Life Cycle & Meiosis

form of sexual reproduction

2 consecutive cell divisions

Meiosis I

starts with bivalent chromosomes

Anaphase: Chromosome disjunction

2 haploid daugher cells

Meiosis II

no homologous chromosomes

Chromatid disjunction

4 haploid daugheter cells

gurantees continuity of genetic information from 1 generation to another

Subtopic

form of asexual reproduction

single cell division

2 identical daughter cels

limits geographical distribution

temperature

precipitaton

competition

predators and pathogens

soil type

slight variations in niche that allow species to coexist

the maximum individuals of a population that an environment's resources can support

Factors that promote population growth

Rate of reproduction

ability to withstand adverse conditions

defense mechanisms

Factors that oppose population growth

Diseases

Predations & Pathogens

Insufficient food

Competition

Emmigration

Adverse Weather Conditions

BR - DR / 10

State of having more than 2 sets of chromosomes

May result in new species

Unreduced gametes

Hybrids

Tetraploid

Examples: Tragopogon & Triticum

development of new species from common ancestor due to adaptations to different environments

group of plants & animals interconncected by energy and mineral flow

Produceers

productivity

Primary Prodcutivity

Net Primary Productivity=Gross primary productivity - plant respiration

Consumers

Primary

Secondary

Tertiary

Detritivores

23rd Pair of Chromosome (XX or XY)

First 22 pairs of chromosomes

2 sets of chromosomes; one inherited from each parent

Trisomics

Down Syndrome

Monosomics