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

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

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

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