Genetic and sex inhertiance, codominance

Rember after punnet square

ratio

pedigree female

circle

pedigree male

square

not affected

no coloured in

pedigree affected

coloured in

pedigree dead

crossed out

pedigree married

line horizontal

pedigree children

line vertical

pedigree twin

angled line from same point

What is sex determined by

The entire chromosome pair

Why does the father determine the sex of a child

He is the only one with the Y chromosome

What is the femal chromosome and male chromosome

XX XY

Who carried the sex-linked chromsomes

sperm and egg

What do we use in a punnet square that is unusal and why

Chromosomes instead of alleles since sex depends on chromsomes not alleles.

What is codominance

When both alleles within a genotype are expressed in the phenotype of an individual

Give an example of codominant inheritance

blood group

What are the three alleles governing blood groups

I^O I,^A, I^B (supercript

What does I and the releavnt supercript represent

The gene is I and the supercrip is the allele

What are the four blood types

A, AB, O B

What alleles are codominant in blood group

I^B I^A

What are the codominant alleles dominant to

I^O

When are antigens in blood produced or not

I^A I^B will have antigens but I^O will not

What is the phenotype of I^A I^B

AB blood

antigen

surface cell protein that identifies if a cell belong in an organism

Explain how inhertiance of biological sex is determined in humans

Sex is determined by the sex chromosomes x and y which are passed in by gametes where sperm has either X or Y and eggs have only X.

State genetic term for two of same thing (WHAT MUST U REMEBR)

homozygous RECCESSIVE

Was is sex linked inhertiance

When the alleles that control a particular characteristic are found on the sex chromosomes

Where are alleles almost alwayss found for sex-linked inhertiance aND WHY

Only on the X chromosomes as Y chromosome is much smaller.

Why are males more likely to have sex-linked recessive conditions

They only have one x chromsomes

WHy do females have as lower chance of carrying sex linked recessive conditions

They have two copies of the X chromosome and so are likely to inherit one dominant allele