The Arts of Living Things
The biological species concept defines
"species" as a population of individuals
that are able to freely breed under
natural conditions.
Ways to consider biodiversity:
-Genetic diversity
-Species
-Structural diversity
Ways to classify species:
-Morphology
-Behaviour
-Geographic location
Loss of biodiversity means:
-threatened food supply
-eliminates sources of natural medecine
-economic impact on tourism & forestry-cause disruption in biogeochemical cycles.
Binomial Nomenclature:
*Two name system (genus-species)*
Traditional Taxonomic ranks:
-Domain
-Kingdom
-Phylum
-Class
-Order
-Family
-Genus
-Species
All living things are descended
from a common ancestor.
6 Kingdoms of Life:
Eubacteria/Archae/Protists/
Fungi/Plants/Animals
Eukaryotes:
any organism whose cells contain organelles; multicellular.
Prokaryotes:
a single-celled organism that does not contain membrane bound organelles.
They can be identified by cell shape, cell wall and movement.
Reproduce asexually by Binary Fission
Reproduce sexually by Conjugation
-Bacteria have cilia, flagellum to help them move.
-Gram negative (purple)
-Gram positive (pink)
Eubacteria & Archae are difficult to distinguish because of small size and lack of internal structure.
Viruses are non-living
Two ways for a virus to reproduce: lytic cycle & lysogenic cycle.
Protists are the most diverse group!
Were the first eukaryotes (endosymbiotic/ folding/ mitochondria & chroloplast).
Binary-fission (asexual)
Conjugation (sexual)
Can be:
Animal-like (amoeba)
Plant-like (algae)
Fungus-like (slime moulds)
Fungi have cell walls made of chitin, majority multicellular (yeast-unicellular), bodies are mesh-like (composed of mycelium), not photosynthetic.
-Major decomposers
-Plants rely on fungi for nutrients
-Responsible for cycling through biosphere
Asexual repro. by dispersing spores
Plants evolved from green algae (charophytes),
multicellular, eukaryotic, photosynthetic, most terrestrial, cell wall made of cellulose etc.
4 main groups:
-Bryophytes
-Pteridophytes
-Gymnosperms
-Angiosperms
Animals could be vertebrates or invertebrates.
-Radial (jellyfish, starfish)
-Bilateral (human)
Most animals are protostomes.
"Cells" divide for growth, development, repair and the formation of gametes.
Genetic information is stored in DNA molecules within the chromosome cells.
-Somatic cells are any cell in the body except sperm &
egg cells.
- 46 chromosomes -----> 2 sets of 23 chromosomes (diploid)
-Sex cells are the egg & sperm cells.
-23 chromosomes -----> 1 set of 23 chromosomes (haploid)
Asexual reproduction=identical offspring from single parent (mitosis)
Sexual reproduction=genetically variable offspring (meiosis)
Mitosis has 3 phases:
1)Interphase
2)Mitosis
3)Cytokinesis
Mitosis: Interphase, Prophase, Metaphase, Anaphase, Telophase, Cytokinesis
Asexual reproduction: binary fission, budding, fragmentation
Cloning is the process of forming identical offspring from a single cell or tissue.
In meiosis- produce four genetically different, haploid(n) reproductive cells.
Two cell divisions; eight steps; reduce # of chromosomes by half; in testes-spermatogenesis/ in ovaries-oogenesis
Meiosis I, involves synapsis, crossing over, formation of tetrads
Metaphase I, homologous pairs line up at the metaphase plate.
Anaphase I, sister chromatids do NOT separate.
-Female-sex chromosomes are homologous (XX)
-Male-sex chromosomes are non-homologous (XY)
Karyotypes are used to view abnormalities (stain, viewed & photographs under a microscope)
Abnormalities could either be monosomy or trisomy non-disjunction.
A monohybrid punnet square codes for one trait.
Dominant alleles may prevent the expression of recessive alleles.
-Homozygous dominant: TT
-Homozygous recessive: tt
-Heterozygous: Tt
Dihybrid crosses are crosses between individuals who differ in two pairs of alleles (usually 9:3:3:1)
Incomplete dominance is a blending of traits.
Codominance occurs when both alleles are fully expressed.
Type O blood is the universal donor.
Type AB blood is the universal recipient
Pedigree charts are used to study the transmission of a hereditary condition.
-Affected female (colored circle)
-Affected male (colored square)
Sex linkage is the passing of traits found on the X chromosome.
**Y chromosome carries no information**
Hemophilia is a recessive X-linked trait.
DNA molecule:
-Double helix
-Twisted ladder
-Thymine(T) & Adenine(A) are complementary bases.
-Guanine(G) & Cytosine(C) are complementary bases.
Nutrients are the chemicals that an organism needs in order to grow, build an and repair tissues and to produce energy.
Nutrients:
Metabolic rate depends on:
-Body size
-Sex
-Physical Activity
-Age
-Hereditary factors
Carbohydrates
Main source of energy
Monosaccharides, Disaccharides, Polysaccharides
Proteins
Building blocks of body
Composed of many amino acids
Lipids
Concentrated source of energy
Help in the absorption of vitamins
Water
The body is made of 55% to 60%
Need to digest food/ get rid of waste products/ chemical reactions
Vitamins
Regulates cell function, growth & development within our bodies
Water or fat soluble
Minerals
Build & repair tissues
Critical in the formation of bone
Digestion in the body
Ingestion takes you to:
Digestion:
-Physical and chemical (amylase)
-Bolus forms and goes down the esophagus (peristalsis)
-Stomach churns and mixes food particles with gastric juice(mucus found in gastric juice for protection)
-Liver produces bile, but gallbladder stores it (pancreas releases hormones and enzymes that'll help the breakdown of proteins)
Absorption:
-Small intestine is where most digestion happens (villi found)
-Large intestine is where the undigested particles are found
Egestion:
-Anus is where the stool is released
Respiratory System
Structure of the lungs:
Thin permeable respiratory membrane through which diffusion can occur
**Pneumothorax causes the lungs to collapse**
----->Difficulty breathing
A large surface area for gas exchange
**Gas exchange happens in the alveoli**
A good supply of blood
A breathing system for bringing-rich air to the respiratory membrane
**Mechanism of ventilation**
----> Exhalation & Inhalation
Tidal volume
Total lung capacity
Inspiratory reserve volume
Expiratory reserve volume
Residual volume
Vital capacity
Circulatory system
Main function:
Transports oxygen to the cells from the lung
Transports carbon dioxide from cells to the lung
Transports essential nutrients to the cells
Carries wastes from cells
Composition of blood:
Blood plasma:
-antibodies/proteins
-nutrients/wastes
Red blood cells:
-carry oxygen
-contain hemoglobin
White blood cells:
-Attack bacteria & other invaders
Platelets:
-control blood clotting process
Types of blood vessels:
Arteries:
-carries blood away from the heart
-usually oxygenated
**Exception pulmonary artery**
-Vasodilation
-Vasoconstriction
Veins:
-carries blood towards the heart
- usually deoxygenated
**Exception pulmonary vein**
Capillaries:
-connect arteries/arterioles to vein/venules
-provides oxygen & nutrients to the cell
**The smallest vessel**
Blood pressure:
Systolic Pressure (heart contracts)
Diastolic Pressure (heart relaxes)
The mechanism that drives evolution is "Natural Selection"
Mutations create new genetic information and add genetic diversity.
Genetic diversity must be present for nature to
favor some individuals over others.
Mutations occur by:
-Substitution
-Insertion
-Deletion
Artificial selection is limited by genetic
variability within the breeding population.
Breeders can't create traits that do not already exist within the population.
Scientists came up with different beliefs...
Aristotle- living things are "Immutable"
Buffon- observed anatomical features (with no purpose).
Carl Linnaeus- classification system.
Erasmus Darwin- believed organisms change over time.
Chevalier de Lamarck- mechanisms of "Use & Disuse"/ "Inheritance of Acquired Characteristics"
Georges Cuvier- "Theory of Catastrophism"
Charles Lyell- "Theory of Uniformitarianism"
Charles Darwin- traveled to "Galapagos Island" & found a remarkable population of plants, birds and reptiles!
**Survival of the fittest**
Types of evidence:
-Biogeography
-Homologous & Analogous features
-Vestigial features
-Competition within populations
Types of natural selection...
Directional selection
Disruptive selection
Stabilizing selection
Sexual selection
What produces evolutionary changes
independently of natural selection?
Genetic drift
Bottlenecks
Founder effect
Types of evolution....
Adaptive radiation
Divergent evolution
Convergent evolution
Coevolution