Genetics Concepts and Punnett Square Analysis

Homozygous

Identical pairs of genes

Law of segregation

Exact alleles an offspring inherits

Outcome of offspring if a dwarf married a heterozygous spouse

50% heterozygous (normal), 50% dwarf

Dominant trait

Always seen if present

Recessive Trait

A trait hidden by the dominant trait

Define Recessive Allele

Only visible when two alleles are present

What is an Allele?

An alternative form of a gene

The father of genetics

Gregor Mendel

Alternate forms of a trait

Allele

Two of the same trait

Homozygous

A visibly seen trait

Dominant Traits

Homozygous dominant could be referred to by?

HH

Homozygous recessive should be represented as?

hh

What is homozygous?

Two alleles are the same

Percent of offspring that will be hybrids when mixing a heterozygous with a homozygous parent

50%

Percentage of these offspring that will be heterozygous

50%

Genotypic ratio of a child whose parents are Dominant homozygous and heterozygous

1:1

Percentage of (true) Dihybrid Genotypes

25%

A dihybrid cross is...

A cross involving inheritance of two alleles for two genotypes

Phenotypic ratio of a (true) dihybrid cross

9:3:3:1

Which of the following shows a (true) dihybrid cross?

SsBb × SsBb

Parent Genotypes in the following Dihybrid cross

BbSs × BbSs

Define Hybrid

Two different alleles, same trait

If seeds are hybrid, his cross-pollinated flowers in F1 are...

Purple and yellow

In a Heterozygous cross, the GTR is

1:2:1

What is a deletion mutation?

Type of frame-shift mutation removing 1 base

What happens during anaphase?

Sister chromatids are pulled away from each other

Offspring can only have a mutation if the mutation affects which type of cell?

Gamete

Longest period of cell cycle

Interphase

What is the key function of the cell cycle (Mitosis)?

All of the above (replace old/damaged/lost cells, generate 2 identical daughter cells, and growth)