Kategorier: Alle - phenotype - genetics - inheritance - alleles

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Mind Maps Biology 2021 Grade 11

Gregor Mendel, often regarded as the father of genetics, made groundbreaking contributions to the understanding of inheritance through his meticulous experiments with pea plants. His work laid the foundation for the principles that govern genetic inheritance, such as the laws of segregation and dominance.

Mind Maps Biology 2021 Grade 11

Biodiversity

Characteristics of Living Things

The first stage of Organization
Eukaryotic Cell: Has a ‘true nucleus’ and is membrane bound; multicellular
Prokaryotic Cell: most ancient cell type; no membrane bound nucleus (i.e. bacteria); unicellular
Where Do We Start?
Species can be classified by:

Phylogenetic Species Concept

Morphological Species Concept

Biological Species Concept

Species do exhibit structural diversity—diversity that is based on external and internal structural forms—that allow us to organize and identify.
All of the millions of species on Earth share certain fundamental similarities
Why is it Important to Classify Living Things?
Classification can assist in:

environmental conservation of organisms

increasing crop yields and disease and pest resistance

tracing the transmission of disease and the development and testing of possible treatments

the discovery of new drugs, hormones, and other medical products

Many groups of peoples, collect plants for medicinal uses—very important to be able to identify the plants.
Doctors need to be able to identify bacteria
Farmers and gardeners need to be able to identify weeds
7 Characteristics of Living Things
7. …adapt to their environment.
6. …reproduce.
5. …grow.
4. …respond to their environment.
3. …use energy for maintenance and growth.
2…have different levels of organization.

Organism - any complete living thing.

Organ system - a group of organs that perform a common function.

Organ - a group of tissues that perform a common function.

Tissue - a group of cells that perform a common function.

Living things organize cells at several levels:

Living things must be able to organize simple substances into complex ones.

Both molecular and cellular organization.

1…are composed of cells.

In multicellular organisms, specialization increases until some cells do only certain things

Single-cell organisms have everything they need to be self-sufficient.

The Three domains
Organisms can be:

Heterotrophic – can not make their own food

Autotrophic – can make their own food

Multicellular – made up of many cells

Unicellular – single-celled; made up of one cell

Eukaryotic – cells that contain a nucleus

Prokaryotic – cells that lack a nucleus

Organisms are placed into domains and kingdoms based on their cell type, their ability to make food, and the number of cells in their bodies.
III. Eukaryota: all life forms with eukaryotic cells
II. Bacteria : more advanced forms of bacteria
I. Archeae: very primitive forms of bacteria
All organisms belong to one of three domains, depending on their characteristics. A domain is the most inclusive (broadest) taxonomic category. A single domain can contain one or more kingdoms.

The Six Kingdoms of Life

III. Domain Eukarya (Eukaryota)
Kingdoms:

Animals (Animalia)

live in diverse environments

Plants (Plantae)

Cell wall of cellulose

most live on land

autotrophic

multicellular

Fungi

Cell wall made of chitin

include yeast (unicellular), molds, mildews, and mushrooms

heterotrophic

most are multicellular (yeast-unicellular)

Protista (Protists)

Some have a cell wall

some are autotrophs, others are heterotrophs

most are unicellular, others are multicellular

eukaryotic

includes any organism that can not be classified as a animal, plant, or fungus

the “odds and ends” kingdom;

II. Domain Bacteria
2. Kingdom EuBacteria

Cell wall made of peptidoglycan

They are unicellular, prokaryotic, some are autotrophic and others are heterotrophic.

They are found everywhere on Earth except extreme environments.

I Domain Archaea
1. Kingdom Archaebacteria

found in thermal vents, hot springs, very salty water, swamps, and the intestines of cows

they thrive in the most extreme environments on Earth; they are often referred to as “extremophiles”

known as “ancient bacteria”; they are the most primitive type of organisms

Cell walls of different compositions

They are different from bacteria in the structure and chemical makeup of their cells.

they are unicellular, prokaryotic and some are autotrophic and others heterotrophic

Eukaryotic Evolution: Endosymbiosis Theory

3. Inner membrane composition
Surely enough these proteins are found on outer membranes of ancient bacteria membranes (supporting the engulfing process)
The inner membrane has proteins that do not exists on the outer membrane .
Cholorplasts and mitochondria have an inner membrane and an outermembrane.
2. Reproduction/binary fission
Choloplasts and mitochondria in eukaryotes reproduce EXACTLY the same way as ancient bacteria
1. DNA and ribosomes
Ribosomes in chloroplasts and mitochondria also have the same structure as ancient prokaryotes (yet the ribosomes in the rest of the eukaryotic cell look different)
The DNA is circular🡪 very similar to ancient prokaryotes
Chloroplasts and mitochondria both contain their own DNA and ribosomes
Evidence in support of the endosymbiotic theory:
Similarities between mitochondria, chloroplasts, & prokaryotes:

3. Inner membrane Composition

2. Reproduce similarly/binary fission

1. Circular DNA and ribosomes

Membrane-Bound Organelles
Chloroplast = membrane-bound organelle that captures sunlight and uses it to make food for the cell
Mitochondria = membrane-bound organelle that produces energy for the cell

Mitochondria and chloroplasts are a result of prokaryotes engulfing purple bacteria ( aerobic bacterium) and photosynthetic bacteria(cyanobacterium)

What Exactly Happened?

Classifying Life

How Do We Name a Species?
Rules when Writing Scientific Names

The entire name must be EITHER typed in italics OR underlined if written by hand

The second name is the species name → this is NOT capitalized

The first name is the Genus name → This is capitalized

Canis familiaris– dogs

Example: Homo sapiens - humans

The scientific name of a species consists of two parts:

Species name

Genus name

Why Do We Classify Organisms?
To determine evolutionary relationships among organisms.
To determine a particular organism
Species: A group of organisms that resemble one another physically, behaviourally, or genetically, and that can interbreed under natural conditions to produce fertile offspring.
The hierarchy is domain, kingdom, phylum, class, order, family, genus and species
Taxonomy-The branch of biology that considers the classification of organisms.

Mostly Micro-Organisms

Bacteria and Medicine
Antibiotics work to stop bacteria from growing by interfering with specific processes that are essential for growth and reproduction

Kill bacteria Inhibit bacterial growth

Bacteria and Health
Clostridium botulinum

The same toxin produced by C. botulium is used for cosmetic purposes to prevent wrinkles and prevent excessive sweating

Causes botulism, a type of food poisoning

Bacteria can:

Produce necessary vitamins

Aid in digestion

Improve the look of wrinkles

Cause disease

Sour milk

Spoil food

Spore Formation
Used to resist extreme environments.
During this stage, endospores do not grow or reproduce
The bacteria form a tough outer covering that surrounds the DNA and a small portion of cytoplasm—forms endospores.
The life cycle of some bacteria include a dormant stage.
Plasmids
They are used to introduce foreign genes into bacterial cells.
Plasmids can be transferred from one bacterial cell to another during conjugation.
Plasmids are small loops of DNA that are separate from the main chromosome.
Chromosomes are not the only part of the cell to contain DNA.
Sexual Reproduction
Asexual Reproduction
Cell Wall Structure
Gram Negative: thin protein layer and stain PINK
Gram Positive: thick protein layer on cell wall and stain PURPLE
Gram stain identifies differences in cell walls such as amino acid and sugar arrangements
Growth pattern
Bacteria often grow in characteristic patterns, or groupings

Strepto- (arranged in chains)

Staphylo- (arranged in clusters (think: grapes))

Diplo- (arranged in pairs)

Shapes and sizes
Vibrio (comma-shaped)
Spirilli (spiral-shaped)
Bacilli (rod-shaped)
Cocci (round)
KINGDOM: EUBACTERIA
Can be classified by their shape, cell wall structure, and source of food and energy
Most live as single cells

Some live in colonies or link together to form filaments

Prokaryotes
Kingdom Archaea
Thermoacidophiles

Use sulfur as their source of energy

Grow best at temperatures above 80°C

Live in hot sulfur springs, volcanoes, deep sea vents.

Heat and acid-loving archaea

Halophiles

To prevent an exodus of water from the cell, halophiles offset the high salt in the environment by accumulating such compounds as potassium and glycine-betaine. This allows a balance of salts inside and outside of the cell preventing water from flowing outward as would be the case if lower salt levels existed within the cells.

The caretonoids give them a pinkish color,

Incorporate pigmentation in the form of bacteriorhodopsin, for photosynthesis, and carotenoids for UV protection.

Live in salt pools (15% salt)

Salt-loving archaea

Methanogens

Methane is the waste product

Use CO2 gas, and H2S as a source of energy

Live in oxygen-free environments (swamps, marshes, sewage disposal plants)

Methane producing archaea

Obtain energy from inorganic molecules or from light
Also called extremophiles

Volcanoes, piles of hot coal, in rocks deep below the Earth’s surface

Hot springs, sea-floor vents, alkaline or acidic waters, saline environments

Found in extreme-environments

Introducing the Virus

Viral Reproduction - Lysogenic Cycle
When viruses infect cells they can sometimes enter into a dormant or "sleep-like" state where we wouldn't see the infection. Although it may seem like the virus isn't doing anything to our bodies, they are slowly replicating.
To exit the lysogenic cycle, some kind of trigger, a chemical, change in temperature or even pH can set off the virus in all the infected cells. At that point the viral infection enters the lytic cycle where we can see the symptoms of the infection.
Step 4: The cell continues to replicate, copying the viral DNA with it's own.
Step 3: Viral DNA mixes with the cell's DNA.
Step 2: The virus' DNA enters the cell.
Step 1: The virus attaches to the cell
Viral Reproduction: Lytic Cycle
Lysis - disintegration of a cell by rupture of the cell wall or membrane.
Step 5:The cell breaks open and viruses are released.
Step 4:New viruses are made inside of the host cell using the DNA and protein in step 3.
Step 3:The cell's DNA is destroyed and the cell is forced to make new viral DNA and proteins.
Step 2:The virus' DNA enters the cell.
Step 1:The virus attaches to the cell
Virus Structure
Tail Fibre - These structures help secure the virus onto it's host ("victim")
Capsid - This protein coat protects the DNA.
DNA - This is the genetic material for the virus
Viruses come in different shapes and sizes, but all have general features that are similar to each other. Pictured to the right is a typical bacteriophage, a virus that infects bacteria.
What is a virus?
When it reproduces it has to take over another cell in order to do so (can’t reproduce on its own)
Can reproduce quickly
Has genetic material (either DNA or RNA)
Non-living

Genetics

Mendel and Monohybrid

Gregor Mendel and the Principles of Inheritance
Mendel and the Pea

Complete Dominance

The only way a short pea plant can be produced is if an offspring inherits two recessive alleles

In our example tall is completely dominant over short

Complete dominance means that one allele is always dominant over the other

Both of the examples that we examined demonstrate complete dominance

Punnett Squares

Let’s explore how a monohybrid cross works by using a Punnett square with an example.

To illustrate how traits are inherited Mendel utilized a Punnett square, which is a tool used to show the various combinations of alleles that result when two parents mate.

This is referred to as a monohybrid cross

When Mendel studied pea plants he initially examined the inheritance of one trait at a time.

Principle of Dominance

Law of Segregation

Each allele comes from one parent’s sex cell that was formed through the process of meiosis

Two alleles code for a trait (e.g. Yy)

Developed by Mendel

When organisms are crossbred only dominant traits will be expressed

Monohybrid Cross

Dominant and Recessive Alleles

Recessive allele

E.g. w is used for a continuous hairline

Designated with a lower case letter

Only expressed in the absence of a dominant allele

Dominant allele

E.g. W is used for widow’s peak

Designated with a capital letter

Expressed when present

From the experiment Mendel concluded that the trait for tall plants was dominant and the trait for short plants was recessive.

Cross-Pollinating Plants

It is through this process Mendel controlled reproduction of the pea plants.

Pollen from another plant is directly applied to purple flower.

The stamens which contain pollen is removed from one plant. This is important to prevent self-pollination.

Crossing the Parent Generation

The parent plants made up the parent generation (P generation)

Mendel cross-pollinated pure-bred plants that were different for one trait e.g. height

Pure breeding Plants

Pure breeding plants always have offspring with the same traits as the parents.

This plant was ideal for several reasons:

Many observable traits to study e.g. flower colour, pea shape

Reproduction was controllable

Could self-pollinate or cross-pollinate

Grew and reproduced quickly

readily available

utilized the pea plant to study the inheritance of traits

Gregor Mendel

Laid down the groundwork for further studies in the mechanisms of inheritance

Became a monk and studied hereditary in pea plants

attended the University of Vienna

Was going to be a high school teacher

Studied math and botany

Patterns of Inheritance
Pure, Homozygous - having the same alleles for a trait
Hybrid, Heterozygous – having 2 different alleles for a trait
Phenotype - the appearance of the trait in an organism
Genotype –the genetic makeup of an organism

Recessive alleles are described using lower case. (do not code for proteins)

Dominant alleles are described using a capital letter. (code for proteins)

DNA & RNA

RNA
Genetic Changes

Causes of Mutations

High Temperature

Chemicals- asbestos, formaldehyde

Radiation- X rays, UV damage

Mutagens

May be Spontaneous

Chromosomal Alterations

Few mutations resulting in chromosomal alterations actually are passed on because Zygote often dies

Homologous chromosomes do not pair or separate correctly: Down’s Syndrome.

Very common in plants, but can happen in all organisms

Part of chromosome may be lost

May occur in meiosis.

Types of Mutations

Frame-Shift Mutation - A single base pair is added or deleted. The entire strand shifts over. Entire protein is changed.

Point mutation- One change in a nucleotide can change the entire meaning.

The dog bit the car.

The dog bit the cat.

Mutations in body cells:

Impaired function of the cell (loss of function) or impaired cell division (cancer)

Not passed to offspring but may be harmful to the individual

A mutations in reproductive cells means the gene becomes part of the organism and can result in:

Death of the organism

Structural or functional problems

Non working proteins

New trait

Mutations- caused by errors in replication, transcription, cell division or by external agents.

Translation to Proteins

Similar to a computer binary code 001100101000111110

64 possible combinations of the 20 AA.

20 AA act like the alphabet for DNA (26 letters make millions of words.)

Nucleotide sequence transcribed from DNA to mRNA is the genetic message. The complete info for life.

There are also STOP codons and START codons

Remember CODONS? (the sets of 3 that DNA is arranged in)

There are 20 possible combinations and as a result 20 amino acids

These code for Amino acids

mRNA leaves the nucleus with the code for the protein

RNA Structure

Contains URACIL(U) vs. of thymine (T)

Ribose sugar vs. deoxyribose

Single stranded vs. double stranded

RNA differs from DNA in 3 ways:

DNA
From DNA to Protein

So how does DNA get its message to the rest of the body?

THE MESSENGER =mRNA

DNA needs a messenger to travel to the cell (ribosomes via rough ER) to make a protein and then the protein can travel all over the body.

DNA does not leave the nucleus.

Proteins fold into complex 3-D shapes and become key regulators – forming muscle tissue, enzymes and controlling chemical reactions.

This information is put to work through proteins.

Sequencing of nucleotides in DNA contain information.

DNA Replication

ALL organisms undergo DNA replication.

Before the cell can divide it first makes a copy of its chromosomes through DNA replication

Each cell in the body has a copy of DNA that was present in the original fertilized egg of the zygote.

Importance of Nucleotide Sequence

Order matters!

SANTA and SATAN same letters different order

SEQUENCING

A-T-T-G-A-C has different information than T-C-C-A-A-A

A cattail, a cat and a catfish are all different organism composed of proteins with the same 4 nucleotides. The difference?

DNA and Genes

It is these proteins and combination of proteins that give us a unique phenotype.

This unique sequence of bases will code for the production of a unique protein.

Each unique gene has a unique sequence of bases.

A gene is a section of DNA that codes for a protein.

DNA Structure

Each nucleotide consists of:

Nitrogenous base

Pentose sugar

Phosphate group

A molecule of DNA is made up of millions of tiny subunits called Nucleotides.

DNA consists of two molecules that are arranged into a ladder-like structure called a Double Helix.

All living things contain proteins and all the actions of living things depend on proteins called enzymes.
DNA achieves control because it determines the structure of proteins.
Although environment has some impact on the traits of an organism, DNA has the final word.

Sex Linkage

SEX-LINKED DISORDERS
Male pattern baldness, red-green colour blindness, myopia, night blindness, hemophilia
Recessive lethal X-linked traits result in death.
Males are at a much greater risk for inheriting sex-disorders because they only inherit one X, so if the X has the allele for the disorder, they will suffer from the disorder.
Most are found on the X chromosome, Y-linked disorders are rare.
Some sex-linked traits are associated with disorders.
SEX-LINKED INHERITANCE
Most known sex-linked traits are X-linked (carried on the X chromosome). This is probably because the X chromosome is much larger than the Y chromosome.
Some traits are located on the sex chromosomes, so the inheritance of these traits depends on the sex of the parent carrying the trait.
SEX DETERMINATION
Therefore the sperm determines the sex of a child
A sperm can donate an X or Y
An egg can donate an X
The sex of an individual is determined by the sex chromosomes contributed to the zygote by the sperm and the egg

Non-disjunction

Results in gametes with incorrect number of chromosomes
When Chromosomes do not divide correctly in meiosis

Heredity and Genetics

co-dominance
Example: In come chickens

Black Chicken x White 🡪 Speckled Chicken

Both alleles contribute to the phenotype.
In codominance, neither allele are dominant; both are expressed. A cross between organisms with two different phenotypes produces offspring with has both phenotypes of the parental traits shown.
Incomplete dominance
Result: Heterozygous phenotype somewhere in between homozygous phenotype.
In Incomplete Dominance, every genotype has its own phenotype. (One allele not completely dominant over the other.) Third phenotype that is a blending of the parental traits. (2 alleles produce 3 phenotypes.)
Dihybrid Crosses
a cross that shows the possible offspring for two traits

Meiosis

Stages
Sex Chromosomes
** If the offspring has one “X” chromosome and one “Y” chromosome it will be a male.
** If the offspring has two “X” chromosomes it will be a female.
The Sex Chromosomes code for the sex of the offspring.
Autosomes
Karyotype
In Humans the “Autosomes” are sets 1 - 22
(The Autosomes code for most of the offspring’s traits)
Homologous Chromosomes
Humans have 23 pairs of homologous chromosomes.

22 pairs of autosomes

1 pair of sex chromosomes

Each locus (position of a gene) is in the same position on homologues.
Homologous pairs (tetrads) carry genes controlling the same inherited traits.
Pair of chromosomes (maternal and paternal) that are similar in shape and size.
Chromosomes
Most organisms are diploid. Humans have 23 sets of chromosomes,
One of the homologues comes from the mother (and has the mother’s DNA).… the other homologue comes from the father (and has the father’s DNA).
If an organism has the Diploid number (2n) it has two matching homologues per set.
Fertilization
A zygote is a fertilized egg
The fusion of a sperm and egg to form a zygote.
Fertilization results in the formation of the Zygote. (fertilized egg)
Fertilization, in Humans, occurs in the Fallopian tube.
During Ovulation the ovum is released from the ovary and transported to an area where fertilization, the joining of the sperm and ovum, can occur.
Somatic Cells and Gametes
Gametes are the “sex” cells and contain only ½ the normal number of chromosomes…. called the “Haploid” number (the symbol is n)….. Sperm cells and ova (egg) are gametes.

The Female Gamete is the Ovum (ova = pl.) and is produced in the female gonad the Ovaries

The Male Gamete is the Sperm and is produced in the male gonad the Testes

Somatic Cells are “body” cells and contain the normal number of chromosomes ….called the “Diploid” number

Cell Division

Asexual & Sexual Reproduction
Sexual

Sexual reproduction is any reproduction that does involve meiosis.

Individuals that are better adapted will survive and perpetuate the species

Sexually reproducing organisms are better able to adapt to changing environments because of differences between individuals

Requires more energy and time than asexual reproduction

(offspring are genetically different from parent)

Genetic information from parent cells are combined to produce a new organism

Asexual

Asexual reproduction is any reproduction that does NOT involve meiosis.

3. There are no specialized structures required by the parent.

2. Often produces many offspring rapidly

1. A single parent gives rise to offspring that are genetically identical to the original parent (clones)

Meiosis vs Mitosis
The purpose of meiosis is to produce gametes (sex cells) which unite during sexual reproduction (the number of chromosomes in each sex cell is half of parent cell)
The purpose of mitosis is to maintain genetic continuity (the number of chromosomes in each daughter cell stays the same)
Phase 4 of Mitosis: Telophase
Organelles are distributed between the two daughter cells and the cell membrane pinches inward
Cytokinesis occurs after telophase:
Single-stranded chromosomes uncoil to become chromatin
Two nuclear envelopes form
Phase 3 of Mitosis: Anaphase
Single-stranded chomosomes are pulled to opposite poles by spindle fibres contracting
Chromatids separate at the centromere
Phase 2 of Mitosis: Metaphase
Centrioles duplicate
Chromosomes line up across the equator of the cell
Spindle fibres attached to centromeres pull chromosomes into place
Phase 1 of Mitosis: Prophase
Nuclear membranes starts to disappear
Spindle fibres form between the centrioles
Chromatin condenses and shortens into chromosomes
Centrioles move to opposite poles of the cell
Interphase
DNA is visible in the nucleus as strands called chromatin
G2 phase: cell prepares for mitosis
S phase: DNA is replicated
G1 phase: cell grows
Mitosis & the Cell Cycle
The cell cycle consists of mitosis, cytokinesis and interphase
Cytokinesis refers to the process of separating the cytoplasm and its contents into equal parts
Mitosis refers to the process of dividing the nuclear material
Mitosis occurs when a parent cell divides to produce two identical daughter cells
DNA Replication and Cell Division
Healing and tissue repair
Growth (e.g. 1 fertilized egg --> human of ~100 trillion cells)
Reproduction (e.g. unicellular organisms)
DNA must replicate so that during cell division, the new cells formed each receive a complete set of genetic information

Evolution

Pathways of Evolution

One Origin, Three Paths of Evolution
Over time, evolution can follow many different paths

Coevolution

Co-evolution is likely to happen when different species have close ecological interactions with one another

Mutualistic species

Competitive species

Predator/prey and parasite/host

Used to describe cases when two (or more) species reciprocally affect each other’s evolution

The evolution of the morphology of a plant may affect the morphology of a herbivore that eats that plant, which may affect the evolution of the plant, which might affect the evolution of the herbivore and so on, and so on

Convergent

An evolutionary pattern when two or more species become increasingly similar in phenotype in response to similar selective pressures

species of different ancestry begin to share analogous (similar in appearance but different evolutionary origins) traits because of a shared environment or other selection pressure

Adaptive Radiation

Species “radiates out” from common ancestor

Commonly occurs after mass extinction

One original species gives rise to three or more species.

Occurs when divergent evolution occurs in rapid succession, or simultaneously, among a number of populations

Divergent

An evolutionary pattern where two species become increasingly different

On a smaller scale, it is responsible for the evolution of humans and apes from a common primate ancestor

On a large scale, divergent evolution is responsible for the creation of the current diversity of life on earth from the first living cells.

Often happens when two closely related species diversify to new habitats

Result of differing selective pressures or genetic drift

Natural Selection

Descent with Modification
Darwin believe that all life has one common origin, and from that origin life diversified to the forms that we see on Earth today.

Change does not demonstrate progress (improvement)...it is simply change.

Each living species has descended, with changes, from other species over time.

Natural selection does not demonstrate progress, but merely results from the ability of species to survive local conditions and to pass on the traits that helped them survive.

Evolution by Natural Selection
Selection

Individuals with traits that are not well suited to their environment either die or leave few offspring.

Evolution occurs when good traits build up in a population over many generations and bad traits are eliminated by the death of the individuals.

The individuals with the best traits / adaptations will survive and have the opportunity to pass on it’s traits to offspring.

Ex: When a predator finds its prey, it is due to the prey’s physical characteristics, like color or slow speed, not the alleles (BB, Bb)

Natural selection acts on the phenotype (physical appearance), not the genotype (genetic makeup)

Competition

Natural selection occurs through “Survival of the fittest”

Not all individuals survive to adulthood

Fitness: the ability to survive and reproduce

Individuals COMPETE for limited resources:

Food, water, space, mates

Variation

The more variation of types of species in an habitat, the more likely at least some will survive

EX: Dinosaurs replaced by mammals

Since the environment changes….

EX: If everyone is the same, they are all vulnerable to the same environmental changes or diseases

The more variation within a species, the more likely it will survive

Adaptation: an inherited trait that increases an organism’s chances of survival

Each individual has a unique combination of inherited traits.

Overproduction

More individuals are born than can be sustained by their environment, which creates a struggle for existence

Each species produces more offspring than survive

Darwin’s Questions

Could species have been modified from an ancestral form that arrived on the Galapagos Islands shortly after the islands were formed?

Why did the Galapagos species so closely resemble organisms on the adjacent South American coastline?

Why would living and fossilized organisms that looked similar be found in the same region?

Why were all types of organisms not randomly distributed?

Darwin’s Observations

Finch beaks were adapted to the food source on each island.

Finches found on islands resembled continental finches but were different in some characteristics.

He found fossils of extinct animals that looked similar , but not identical, to living animals.

The flora and fauna were different in different regions.

Information

Wrote a book called “The Origin of Species” to propose his theory of natural selection, which is a mechanism for evolution

As the ship’s naturalist, he made observations of organisms in South America and the Galapagos Islands

Darwin went on a 5-year trip around the world on the ship, the HMS Beagle

Proposed a mechanism for evolution, natural selection

Father of Evolution

Artificial Selection
Artificial selection is a selective pressure exerted by humans on populations in order to improve or modify particular traits.

chickens bred to produce more eggs

cows bred to increase muscle for meat consumption

cats bred for appearance

Selective Pressure

to select for certain characteristics in some individuals and select against certain characteristics in others

change in competition

change in predators

light level change’

temperature change

If an organism produces offspring that also survive to reproduce, that organism is said to be fit for the environment.
Natural selection describes the process of change in the characteristics of a population of organisms over many generations.
Recap: Variation in Species
Adaptations are the result of a process of gradual, accumulative changes due to mutations, that help an organism survive and reproduce
A mutation is a permanent change in the genetic material of an organism and is the only source of new genetic variation.
Variation is created by the different combinations of genetic information (alleles) that offspring inherit from their parents.

Theories of Evolution

Charles Darwin
There are three types of natural selection:

3. disruptive selection

Large lobsters mate by force and small lobsters sneak in female populations in alpha male territory

Example - mating lobsters

Select against average or intermediate phenotype because it is less fit than the extremes

Selects for (favours) 2 extreme phenotypes that each have specific advantages

2. directional selection

Selects against other phenotypes

Selects for (favours) one extreme phenotype

Populations genetic variance shifts towards a new phenotype when exposed to environmental change

1. stabilizing selection

Results in a decrease of populations genetic variance

Selects against extreme phenotypes

Selects for (favours) average phenotypes

Descent with Modification - changes do not demonstrate progress (improvement) - it is simply change
Organisms with traits that are better suited will survive, reproduce, and pass on those traits to offspring
Selective pressures determine which organisms survive - “survival of the fittest”
Variation exists within species - mutations are the sources of variations
Stephen Jay Gould & Niles Eldredge
Punctuated Equilibrium

Balance of stasis and punctuated events

During periods of stasis change is slow, however, sudden events (punctuated events) i.e. a flood or volcanic eruption can put huge selective pressures on a population requiring a rapid rate of evolution in a short time frame

That evolution occurs both gradually and in small punctuated events

Thomas Malthus
Populations are limited by: predators, food, shelter, water, disease, competition
Carrying capacity is the sustainable balance achieved between population and environment
- May lead to creation of new species if separation continues
- Leads to selection of those more suited to survive
- Break or sudden event interrupts
Jean-Baptiste Lamarck

Traits cannot be gained just because they would be useful

Doesn’t reflect how we inherit traits

Inheritance of Acquired Traits (use and disuse)

Body parts that are not used would be lost over time

Traits acquired during an organism’s life can passed on to offspring

Organisms become increasingly better adapted to their environments

Theory states that species increased in complexity over time until they reached a level of perfection

Georges Cuvier
(other information…)

Suggested that catastrophes killed many species (catastrophism) and that these events corresponded to the boundaries between the fossil strata

Discovered that the oldest fossils are in the deepest layer

Discovered that each stratum (layer) of rock held a unique group of fossil species

Limitations in Theory

Doesn’t take into account that changes can also be slow and subtle, specifically changes within a population

Theory of Catastrophism

Theory of catastrophism states that natural events like floods and volcanic eruptions killed species living in a region and allows species from neighboring areas to repopulate an area, resulting in change

Noted that species are found in particular rock layers and that new species appear and disappear over time

Developed Paleontology - the study of ancient life through fossils

Charles Lyell
Limitations of Theory

Doesn’t take into account varying geological processes like natural disasters, catastrophes, climate change, impact of human activity

Principles of Uniformitarianism

Provided a geological perspective that inspired Darwin

Slow subtle processes that happen over a long period of time lead to substantial changes in the long term

Theory states that geological processes operate at the same rate today as they have in the past

Speciation

Types of speciation
Sympatric Speciation

Occurs in populations that live in the same geographic area

Happens when gene flow is diminished by:

Sexual selection

habitat differentiation

Polyploidy

Less common than allopatric speciation

Parapatric Speciation

Occurs when part of a population enters a new habitat bordering the range of the parent species

Some gene flow may occur between populations in border zone

Allopatric Speciation

Gene flow is interrupted when a population is divided into geographically isolated subpopulations

Basic info
can be caused by a change in just 1 gene or a set of genes causing some sort of isolation
Rate of speciation depends on generation, time, environmental conditions, etc.
Development of a new species through a variety of factors

Macroevolution

Subtopic
Reproductive Isolating Mechanisms
POST-ZYGOTIC mechanisms that prevent development of a zygote

Hybrid breakdown

the first generation hybrids are fertile, but when these hybrids mate, offspring of the next generation are sterile or weak.

Hybrid sterility

even though the hybrid is healthy and vigorous, it is not able to reproduce

Hybrid inviability

even though the zygote is created, it fails to develop to maturity due to genetic incompatibility

PRE-ZYGOTIC mechanisms that prevent mating or fertilization

Gametic isolation

two populations exchange sperm and eggs but rarely fuse to form a zygote

Mechanical Isolation

two populations do not exchange alleles because they are anatomically incompatible

Ecological/Habitat Isolation

two populations do not exchange alleles with each other because they are in different geographic places or at different places within the same ecosystem

Temporal Isolation

two populations do not exchange alleles because they are only available to exchange alleles at different times of year or even of the day

Behavioral isolation

two populations do not exchange alleles because they do not respond to each others mating rituals

Macroevolution: major evolutionary change. The term applies mainly to the evolution of whole taxonomic groups over long periods of time.

Mechanisms of Microevolution

Non-Random Mating
Sexual selection is natural selection for mating based, in general, on competition between males and choices made by females

Often, males and females in a population have drastically different physical characteristics such as colourful plumage in male birds and antlers in male deers - this difference is called sexual dimorphism

Inbreeding occurs when closely related individuals breed together

As homozygous genotypes become more common, harmful recessive alleles are more likely to be expressed

Close relatives share similar genotypes, so inbreeding leads to increases in frequency of homozygous genotypes

is the mating among individuals on the basis of mate selection for a particular phenotype or due to inbreeding

This is in contrast to random mating where breeding partners are randomly selected - the likelihood of specific genotypes mating is based on the allele frequencies within a population

The Effect of non-random mating is that it increases the proportion of homozygous individuals in a population

Genetic Drift
The Bottleneck Effect

is the changes in gene distribution that result from a rapid decrease in the population size

Since the survivors have only a fraction of the original population alleles, the gene pool has lost diversity

Starvation, disease, human activity, and natural disasters can quickly reduce the size of a large population

The Founder Effect

is a change in a gene pool that occurs when a few individuals start a new isolated population

Occurs frequently on islands

Diversity in the new gene pool will be limited

These founders will carry some, but not all, of the alleles from original population

Often, new populations are formed by only a few individuals, or founders

Genetic drift is the change in frequencies of alleles due to chance events in a breeding population

Think of flipping a coin 1000 times versus 10 times

Sample size can greatly impact the gene pool of a population - the smaller the population, the more likely that the future generations won’t reflect the parent generation

Gene Flow
Gene flow may change allele frequencies in either or both populations through a “flow”, or movement of genes (alleles)
Gene flow describes the net movement of alleles from one population to another as a result of the migration of individuals
Mutations
Mutation are the only way that new alleles are introduced into populations
The effect of mutations is that they introduce new alleles into a population, which changes allele frequencies
Mutations are changes that occur in the DNA of an individual, a heritable mutation has the potential to affect an entire gene pool
Basic Information
Genes

We have two alleles for each gene. These alleles "work" together in determine what our hair colour, height, eye colour etc will be.

These variations of a gene are called alleles.

Whenever we look at any trait, such as hair colour, we have variations of that trait (e.g. red, black, blonde and brown).

Genes are segments of DNA that code for a specific trait, such as hair colour, eye colour, height, eyelash length etc.

These changes when sustained over many generations and a long period of time can lead to macroevolution and the creation of a new species
Microevolution is the change in the allele frequency for a population

Evidence for Evolution

Evidence from DNA
For example, humans and chimpanzees have more similarities in their DNA than humans and dogs, so humans and chimpanzees have a more recent common ancestor.
If two different organisms have similar patterns in their DNA, then they must have both inherited that DNA from a common ancestor.
We know that organisms pass on DNA to their offspring (children).
DNA is the blueprint for an organism and scientists have been able to determine how closely related two organisms are by comparing how similar their DNA is.
Evidence from Embryology
For example, all vertebrates have similar stages of early embryo development because all vertebrates have a common ancestor.
Embryology has been used to determine relationships between different organisms.
Embryology is the study of the early pre-birth stages of an organism’s development.
Evidence from Biogeography
Also, organisms on islands often closely resemble animals found on the closest continent. Lemurs are only found on Madagascar but there are lemur fossils in India (Madagascar broke off from India 88 million years ago).
For example, cacti are only found in the Americas even though there are deserts in Africa. Since all cacti have a common ancestor, it makes sense that they are located in the same parts of the world.
Organisms that live closely together are more similar than organisms that live far away but in similar habitats.
Biogeography is the study of the distribution of organisms throughout the world.
Evidence from Anatomy
Also, some organisms have what are called vestigial structures. Vestigial structures are those that have lost their function but exist because they had a function in a common ancestor. For example, some birds have wings but can’t fly (like the Kiwi bird).
Even though they are used for different functions, they all contain the same set of bones, and are organized in similar ways because they all originated from a common ancestor.
Vertebrate forelimbs can be used for various functions, such as flying (bats), running (horses and cats), and swimming (whales and seals).
Homologous structures are those that have similar structural elements and origin but may have different functions.
Evidence from Fossil Records
When an organism dies, it may form a fossil. A fossil is the remains or impression of a prehistoric organism cast in rock. The following data has been collected around the world:

fossil records show that fish are the oldest vertebrates (animals with backbones) and it isn’t until more newer layers of rock do you find other vertebrates (reptiles, mammals, birds, etc.).

Fossils appear in chronological order in the rock layers.

Fossils found in young layers of rock (rock closer to the surface) are more similar to species living today than fossils found in older deeper layers of rock.

Adaptation & Variation

Selective Advantages
A selective advantage is a genetic advantage that improves an organism’s chances of survival in terms of both survival in a changing environment and reproduction.
Adaptation & Survival
Mimicry is a type of structural adaptation. Harmless species physically resemble a harmful species. Predators avoid the harmless species as much as they do the harmful one.
Adaptations are the result of a process of gradual, accumulative changes due to mutations, that help an organism survive and reproduce.
Variations Within a Species
Interaction with the environment determines whether a variation is positive or negative for the individual organism.
These changes are the result of random, heritable mutations in DNA that accumulate over generations.
The variations within a species are the structural, functional, or physiological differences between individuals.

24 Hour Biological Timeline

9 PM to 11:59 PM
6 minutes after 9 the first multicellular life forms appear on Earth, first it was:

Humans (11:59:30)

First mammals

Dinosaurs

Reptiles

Insects

Fish, then

1 PM to 9PM
Increase in oxygen concentration allowed for more complex life forms to thrive as we need more oxygen to perform cellular respiration

Cellular respiration is a process where we take glucose and convert it into ATP (a usable energy molecule for our cells)

The increase in oxygen concentration allowed for the formation of the ozone layer

Protects us from harmful ultraviolet radiation from the sun

Oxygen levels rise from less than 1% to 21%
5 AM to 1 PM
These bacteria produced oxygen gas as a by-product which filled the oceans with oxygen gas and eventually the air
Evidence of this transition can be found with stromatilites found in Western Australia
Bacteria that had chlorophyll was able to survive and reproduce passing along their trait to the next generation

These bacteria are distant relatives to the cyanobacteria that we find on Earth today

These bacteria are able to conduct photosynthesis and produce sugar to survive

Life was able to move to the surface
The heavy bombardment ended
12 AM to 5AM
First Life Forms

Archaebacteria

Carbon, nitrogen, oxygen and hydrogen

Elements key to life on Earth are present

Various types of archaebacteria such as:

Halophiles – can live in environments that are very salty i.e. dead sea and pink sea salt formed from bacteria

Methanogens – can live in methane rich environments i.e. the bacteria found in the South African mines

Acidophiles – can live in acidic environments i.e. snotites and phlegm balls

Bacteria capable of living in extreme environments

Though to first evolve 3.8 Billions of years ago

Heavy Bombardment Period

No oceans

This period of time was thought t o aid in the formation of amino acids

Earth was frequently hit by asteroids and meteors

Atmosphere filled with carbon dioxide and hydrogen sulfide

Catastrophic beginning with lots of collisions (ie. Mars sized object hit the Earth to form our Moon)

Animal Systems

Digestive System

Elimination of Wastes

Anus: Controls discharge of waste (feces).

Rectum

Collects waste for excretion.

Chemical digestion is finished at the large intestine.

7. LARGE INTESTINE

Absorption

Lacteals: are small vessels that transport fat to the circulatory system

Microvilli: are a microscopic projection on cell membrane

Villi: small finger-like projects that extend into the small intestine which increase surface area for absorption.

Gall Bladder:

Releases bile when chyme is present in the small intestine.

Stores bile (if stomach empty)

Liver

Recycles damaged red blood cells

Responsible for detoxifying blood (ex. Alcohol)

Removes excess sugar from blood and stores it.

Produces bile for physical digestion of lipids.

Colon is largest part of large intestine; stores waste so that water as well as some inorganic salts, minerals and vitamins can be absorbed.

Cecum – storage (chyme); ends with appendix.

Wider and shorter than the small intestine.

6. SMALL INTESTINE

Small Intestine Absorption

Fats

Lipase is broken down into absorbable fat that enters the lacteals of the villi in the small intestine

Lipase is an enzyme produced and released by the pancreas

Bile is chemically digested with the use of lipase

Bile is produced by the liver and stored in the gall bladder

Are physically broken down from large fat droplets into smaller fat droplets with the use of bile

Amino acids are absorbed into the capillaries of the villus

Trypsin, an enzyme produced and released by the pancreas breaks down polypeptides into amino acids

Broken down into amino acids

complex carbohydrates are broken down into simple carbohydrates like glucose with the use of an enzyme called amylase

these simple sugars (monosaccharides) are absorbed into the capillaries of the villus

amylase is produced and released by the pancreas

nutrients are broken down and absorbed

3 Parts

Ileum: less absorption occurs here, unabsorbed particles are pushed through.

Jejunum: has many folds that continue breakdown and absorption of remaining proteins and carbohydrates

Duodenum: most digestion occurs here

5. STOMACH

Food broken down into chyme(thick liquid).

juices

Pepsinogens

enzymes that when exposed to a low pH (1-3) such as conditions in the stomach, turns into its active form pepsin which is a enzyme the digests proteins

Gastric juice

Hydrochloric acid (HCl) mucus, pepsinogens and other materials

Movement of food in and out of stomach is regulated by sphincters

Pyloric sphincter: regulates food from stomach to small intestine

Esophageal sphincter: regulates food from esophagus (acts like a valve)

J-Shape organ that can store up to 1.5 L of food

4. ESOPHAGUS

Peristalsis: rhythmic, wavelike contraction of smooth muscle that moves food through the esophagus

3. Epiglottis:

Protects / prevents food from entering the windpipe.

Covers the trachea

2. Pharynx:

Divides food and air

Swallowing (gag/swallow reflex)

1. MOUTH

Saliva

At this point food can be “tasted”

Dissolves food particles

Lubricates food to be swallowed

Contains amylase which breaks down complex to simpler carbohydrates

Fluid secreted by salivary glands

Tongue

Helps swallow (movement of food)

Has taste buds.

Strong muscle.

Teeth

Used for mechanical/physical digestion (mastication). They are necessary for breaking food into smaller particles.

molars: crushing

pre-molars: grinding

canine: sharp for tearing

incisors: specific for cutting

Digestion
4 Stages in Digestion

4. Elimination

The removal of waste food materials from the body.

3. Absorption

The transport of digested nutrients to tissues of the body.

2. Digestion

smaller components by enzymes.

The breakdown of complex organic molecules into

1. Ingestion

The taking in of nutrients

Types of Digestion

Chemical: enzymes and water break down food so that it can eventually be absorbed by body cells.

Physical/Mechanical: is the act of breaking down food into smaller pieces using teeth (mastication), as well as contractions of the stomach.

Energy
Nutrients aid in GROWTH, MAINTENCE and REPAIR of tissues.
Supplies body with energy and raw materials for synthesis of chemical compounds.
Organic compounds

Vitamins

We do not obtain energy from vitamins; however, some vitamins are necessary to run energy-related processes in cells.

Vitamins play many different roles in metabolism.

Minerals

Most minerals can be found in whole grains, fruits, vegetables, nuts, and meats. Highly processed foods may be deficient.

Sodium, potassium, zinc, iron, calcium,magnesium among the minerals that humans need.

Proteins

Examples: insulin, enzymes, hemoglobin, collagen, antibodies

Amino acids from digested proteins are used by cells to build all the proteins that our body needs. Proteins provide structure and support, speed up chemical reactions, provide immunity, transport ions

Carbohydrates

Examples: fructose, lactose, cellulose, glycogen, maltose, glucose

Glucose is needed by all body cells as energy. Nerve cells must have glucose to operate.

Sugars and starch are the carbohydrates that humans can digest. “Fiber” is indigestible carbohydrates, such as cellulose and inulin.

Lipids

Lipids are used for storing energy, making cell membranes, and synthesizing steroid hormones.

Lipids are energy dense, containing 9 calories per gram.

Examples:are fats, oils, and waxes.

Medical Technologies

Computer software used in viewing 3D models of
Modelling consists of 3 phases:

Images and data from the body’s movement is combined with computer software to create a 3D model

Walking in a lab attached to infrared markers on pelvis and knees

Using a CT scanner, images are taken

Ultrasounds
A transducer is placed on the body which emits sound waves. These sound waves reflect off structures and interpreted by a computer which displays an image
Viewing internal anatomy using high frequency sound waves
Arthroscopic Surgery
Used to fix ligaments, repair tendons
Small incision, minimally invasive , less scarring, quicker recovery
Nuclear Medicine

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Allows us to look into the body and make appropriate diagnosis and treatment decisions
A radiopharmaceutical is injected and concentrates in the disease areas
CAT Scans

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A contrast medium will be injected to enhance imaging
Takes many x rays form different angles to create a 3D image of your internal body
Magnetic Resonance Imagining (MRIs)

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4 parts :

Software: creates pictures out of the data

Computer: collects data picked up by the antenna

Antenna: detects radio signals given off by the water molecules

Magnets: causes water molecules to line up in one direction and spin around to give off energy

Magnetic resonance imaging
Lasers

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Risks (not high): blurry vision, partial or complete blindness
Laser breaks down bonds or organic material in the eye so that the surgeon can reshape the cornea
Surgery that can help change the shape of the eye and its focal point
Endoscopes
Used to detect abnormalities in the small intestine (ex: tumors, bleeding)

Respiratory System

Structure
Lower Respiratory

Diaphragm

Dome shaped, thin, muscular

Increases and decreases volume of chest cavity

Pleural membrane

Filled with fluid that reduces friction between lungs and chest cavity during inhalation

Reduces friction between lungs and chest cavity

Surrounds lungs and lines chest cavity

Aveoli

Coated with “surfactant” (a lipoprotein) to prevent sticking.

Single cell layer, surrounded by capillaries.

Very thin tiny sacs (large surface area).

~150 million per lung!

Site of external respiration (gas exchange).

Bronchioles

NO cartilage rings

Smooth muscle walls

Many branched tubes, smallest passageways, to increase surface area

Able to change diameter to regulate air flow

Many branches carry air to alveoli

Bronchi

Full cartilage rings for support

Each carries air into lungs and splits into many bronchioles

One goes to each lung.

Upper Respiratory

Trachea

Semicircular cartilage rings to prevent collapse -Cilia and mucus

~10-12cm long

Filter particles

Passage of air into 2 bronchi, “windpipe”.

Larynx

“Adam’s Apple” – a thick band of cartilage that surrounds and protects the larynx.

Two flaps of cartilage, vibrate when air passes through

Contains the vocal chords – for sound, aka “voice box”. Opening to lungs

Epiglottis

Small, flexible flap of tissue

A flap that prevents food from entering the lungs by blocking the glottis (opening of trachea)

Pharynx

Cilia in top portion move food towards mouth to be swallowed

Connects nasal and oral cavity to larynx

Nose and Mouth

Human Adaptations
2. The respiratory surface must be large( inorder to exchange oxygen and carbon dioxide quickly enough to meet the body’s needs)
1. Water must be present at the respiratory surface(moist enviornments allows for gases to dissolve in water)
Composition of Air We Breathe
1% CO2 and Trace Elements (e.g., Argon)
21% Oxygen (O2)
78% Nitrogen (N2)

The Circulatory System

Problems of the Circulatory System
Heart Attack is a blockage of the flow of blood to the heart.
Stroke usually results from blood clots that block vessels in the brain, or from the rupture of a blood vessel.
Hypertension: is a condition in which blood pressure is consistently higher than normal, which can lead to heart attack, stroke, or kidney failure.
Hemophilia is a disease in which the blood plasma does not contain substances that help the blood to clot.
Leukemia is a disease in which extra white blood cells are produced.
Anemia is an abnormally low level of hemoglobin, a protein that binds to oxygen in red blood cells.
Blood Pressure
Diastolic Pressure

As your heart relaxes to refill, blood pressure is at its lowest point.

Systolic Pressure

as your heart contracts to push blood into your arteries, your blood pressure is at its highest point.

Blood
Platelets

help blood form a clot at the site of a wound. A clot seals a cut and prevents excessive blood loss.

White Blood Cells

help fight disease and infection by attacking germs that enter the body.

Red Blood Cells

carry oxygen to cells and carbon dioxide away from them.

Plasma

92% water. It transports blood solids, nutrients, hormones, and other materials.

Blood Vessels
Capillaries

Very thin, small red blood cells travel in single file in capillaries

Site of gas, waste, and nutrient exchange

Veins

Carry deoxygenated blood

Carry blood from the body towards the heart

Arteries

Have thicker walls because the pressure in the arteries is highe

Carry oxygenated blood

Carry blood away from the heart

The Heart
The L ventricle pumps blood to the aorta which distributes the oxygenated blood throughout the rest of the body.
From the L atrium blood flows to the L ventricle.
The oxygenated blood is brought back to the heart by the pulmonary veins which enter the L atrium.
The R ventricle pumps the blood to the lungs where it becomes oxygenated.
Blood enters the R atrium and passes through the right ventricle.
circulatory system
Systemic Circulation

It picks up carbon dioxide and waste products.

It carries oxygen and nutrients to the cells.

Systemic circulation provides a functional blood supply to all body tissue.

Pulmonary Circulation

transports oxygen-poor blood from the right ventricle to the lungs where blood picks up a new oxygen supply. Then it returns oxygen rich blood to the left atrium.

Two Types of Systems
Closed Transport System

blood is pumped around the body in a network of vessels (for collection, distribution and exchange) blood circulates in only one direction Gases and nutrients must pass through walls of blood vessels to reach cells

Open Transport System

blood bathes the cells directly Moves through muscle contractions

Plant Unit

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Application of Plant Hormones

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Native plants
Able to survive harsh conditions
spoiled
raspberry spoiling others

ethylene gas causes all other to ripen

released ethylene gas

one spoiled

herbicides
Excessive growth to kill

Gibberellins

cytokinins

Auxins

Growth
Not grow as much
Away from light
Kill weeds
Limit growth

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Availability

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Publishing information

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Author

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Response to Environmental Stimuli

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Nastic Response vs. Tropism
Tropism

Thigmotropism

The response will continue resulting in a “winding” effect

The side of a plant in contact with a surface of a stimulus will produce auxins on the non-contact side, producing growth

Thigmotropism is the growth of a plant in response to contact

Gravitropism

Plant’s response will be to return to the upward position

The stem demonstrates negative response by growing against gravity

The roots demonstrate positive response by growing towards gravitational pull

Gravitropism is a plants natural growth response to the effects of gravity

Phototropism

Less auxins produced on the side of the plant towards the light

Phototropism is a growth response of a stem towards light, so that it can receive the maximum amount of light for photosynthesis

Tropism: A plant’s growth response to external stimulus coming from one direction in the environment
Nastic Response: A plant’s movement in response to a stimulus that is not associated with the direction of the stimulus
Terms
Plant adapt to new situations by modifying their growth, by means of chemicals called growth regulators[hormones].
Response is a form of defence that allows organisms to survive.
The ability to detect change and to respond is called sensitivity.

Successtion

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Ecological Disturbances
The greater the plant diversity in an ecosystem, the more resilient the ecosystem is to disturbances
i.e Fallen trees open spaces in the canopy, allow shade intolerant plants the opportunity to establish themselves
Provide opportunities for other plant growth
They are frequent and important
Secondary Succession
Often seeds and roots remain, some seeds will only germinate after a fire i.e. Jack or Lodge pine
It is the recolonization of an area after an ecological disturbance in which the soil remains in tact.
Primary Succession

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Climax community is the final stage of ecological succession. i.e. mature oak/hickory forest
Plants compete for light and space, some species better able to survive in changing environment
i.e. after glacial retreating, cooled lava, geologic upheaval
Establishes a community in an area of exposed rock that does not have topsoil

Plant classification

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Adaptations
Rainforest

some plants do not obtain enough nutrients from the soil and consume insects such as the Venus fly trap and the pitcher plant

competition for sunlight results in some plants called epiphytes that grow on trees with trailing roots such as orchids, some mosses and ferns

great competition for pollinators by use of complex flower structures and scents

Desert

Waxy skin to reduce water loss

Spines prevent predators from getting to the water

Have accordion pleats to allow the plant to expand

Catci are capable to storing large quantities of water e.g. 6 m tall cactus can store 400 L of water

Long shallow root systems

Arctic

faster lifecycle to take advantage of the limited sunlight

built in antifreeze to withstand the cold

Roots are shorter and the plants are shorter

mosses, lichens, trees and shrubs live here

Gymnosperm vs. Angiosperm
Angiosperm

Most abundant plant form on Earth

Best adapted to the various climates on Earth

Play a large role in feeding people

Fruits are designed to disperse seeds

Plants bear fruits

Often called flowering plants (but not all of them are flowering plants)

Gymnosperm

Wide spread root systems (anchor themselves and helps to get nutrients)

Tend to be found in harsh environments, found worldwide

Generally trees

Requires pollen to produce

Do not produce seeds or fruit

Most are cone bearing

Most have long, thin needles (these are their leaves)

Seeded vs. Seedless
Seedless

Seedless plants do not have seeds and are spread by windblown spores. They tend to live in moist areas and examples include ferns and horsetails.

Seeded

Seeded plants contain an embryo surrounded by a seed coat. Inside the seed is nutrients that help feed it as it grows.

Vascular vs Non-Vascular

Select as needed:

available

unavailable

Non Vascular

No system of vessels to transport water and nutrients (xylem and phloem) No true leaves, roots or stems Depend on diffusion, osmosis and active transport to get nutrients Need to grow close to water (for reproduction and growth) Grow close to the surface and when they die they leave soil for plants to grow

Vascular

A vascular plant has specialized tissue that helps to transport water and nutrients Most plants are vascular to transport water and nutrients(xylem and phloem) Have roots, leaves and stems ability to live away from major water sources e.g. ponds, lakes Ex. Flowers, trees, shrubs and grasses

Introduction

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Plant Behavior

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Protection

When preyed on it will releases SOS signal that predators will take care of

Tobacco plant uses nicotine poisons to induce seizures, paralysis, adn morality

No Roots

Knows which plant it likes more

Obligate Parasites lives off host

Producing it's own food

Roots

Plant roots slow down when passing nutrients for efficiency

Plant roots accelerate growth to travel to patches of nutrients

Growth towards the sun