Mendelian Genetics (Basics)

A simplified explanation of meiosis could be?

Divide-Restore

in a diploid plant, where do the two alleles for each gene come from?

1 from the egg, 1 from the pollen

if a plant has 2 different alleles, where can each allele go?

1 can go to an egg, the other can go to the pollen, or vice versa

What do Punnet squares help with?

organizing alleles

What is homozygous?

when an organism has both copies of the same allele

what is heterozygous?

when the two alleles in an organism are not the same

what can be used if there are more than two forms of an allele in an organism

superscript numbers

if there are two forms of an allele, how are they differentiated?

Capital letter, lowercase letter

(Homozygotes, Heterozygotes) are considered true breeding

Homozygotes

(Homozygotes, Heterozygotes) Segregate

Heterozygotes

Segregation can be described as…

Different alleles go to different gametes

how are alleles defined?

heterozygote phenotype

the Dominant allele is…

the allele expressed in the heterozygote phenotype

The recessive form of an allele is typically…

broken or nonfunctional

T/F: Organisms can be carriers for recessive traits because in most cases the dominant gene compensates

True

What can incomplete dominance be described as?

An intermediate phenotype

what is an example of incomplete dominance?

Red flower x White Flower = Pink Flower

T/F: Solid color x no color = spots is an example of codominance

False. That is an example of mosaics

T/F: Codominance is super rare

True

What is an actual example of codominance?

Blood types (A, B, O, AB), Self Incompatibility

Codominance is…

Both alleles are expressed at 100% in each cell

Dominance is dependent on…

Perspective

What is a typical phenotypic and genotypic ratio for combining two heterozygotes of Bb

¼ BB, ½ Bb, ¼ bb (Genotypic) (1:2:1)

¾ B, ¼ b (Phenotypic) (3:1)

Is a gene’s dominance always obvious in nature?

No, sometimes the dominant gene may be being selected against by environmental conditions or predators, which can make it harder to predict.

Segregation is like..

flipping two coins

What do different letters represent in a dihybrid cross?

Different genes

Most genes are separated _____ in gametes

independently (Independent assortment)

T/F: As more genes are added, Punnet squares become less effective

True

What becomes better when working with many genes?

fractional trees