ap Bio Unit 5 topics 1-3

Genes

Genes

Segments of DNA that code for basic units of heredity

What alternates in sexual life cycles?

Fertilization and MEIOSIS

Fertilization

A sperm cell (haploid) fuses w an egg (haploid) to form a zygote (diploid)

A dihybrid cross results in what ratio of phenotypes

9:3:3:1

Is AaBb x AABB a dihybrid cross?

No, dihybrid crosses are hetero x hetero

What does a monohybrid cross result in?

Phenotype: 3:1

Genetic: 1:2:1

Allele

Alleles are alt versions of genes

2n = 40, how many pairs of homologous somatic cells?

20

Stage of meiosis where an abnormality would happen!

Anaphase 2

Meiosis is exposed to a toxin, hat stages would be most affected?

Anaphase 1 & 2

AABbCCDd x how mnay unique gamates?

4

Law of independent assortment

The alleles of 2 or more diff genes get sorted into gamates independently from one another

Whihc chromosomes do NOT determine the sex of the organism?

Autonomies

Fertilization

Two gametes fusing together

When 2 gametes fuse during fertilization, what do they form?

A zygote

Crossing over (occurs in the chiasmata)

When the homologous chromosomes pair up and trade sections of dna

Synapsis

In Prophase 1; homologous chromosomes pair up and physically connect to each other (this forms a tetrad)

When 2 sets of homologous chromosomes pair up to cross over prophase 1, what do they form?

A tetrad

True breeding

The process of passing the same PHENOTYPIC traits to offspring after generations of SELF BREEDING