B17 Inherited change

Question 1

What is a gene

Answer 1

A sequence of bases on a DNA molecules that codes for a protein which results in a characteristic

Question 2

What is an allele

Answer 2

A different version of a gene

Question 3

What is the definition of genotype

Answer 3

The genetic constitution of an organism

Question 4

What is the definition of phenotype

Answer 4

The expression of the genotype and its interaction with the environment

Question 5

Dominant allele

Answer 5

An allele whose characteristic is always expressed even if there is 1

Question 6

Recessive allele

Answer 6

An allele that is only observed in the phenotype if 2 copies are present

Question 7

Co dominant alleles

Answer 7

When both types of alleles are expressed in the phenotype

Question 8

Locus definition

Answer 8

A fixed position of a gene on a chromosome

Question 9

Homozygote

Answer 9

An organism carrying 2 copies of the same allele

Question 10

Heterozygote

Answer 10

An organism carrying 2 copies of different alleles

Question 11

Monohybrid inheritance

Answer 11

Inheritance of a characteristic controlled by 1 single gene

Question 12

Genetic diagram for monohybrid inheritance of 2 homozygous parents for dominant and recessive

Answer 12

Check online lol

Question 13

What is the F1 generation/ offspring

Answer 13

The first set of offspring

Question 14

F2 offspring

Answer 14

I think it’s crossing over the F1 offspring

Question 15

Ratio of heterozygous dihybrid cross

Answer 15

9:3:3:1

Question 16

Ratio of heterozygous dihybrid cross

Answer 16

9:3:3:1

Question 17

What makes a sex linked characteristic

Answer 17

Allele coding for a characteristic is located on a sex chromosome

Question 18

Is Y smaller than X

Answer 18

Yes

Question 19

Why do males more often get recessive linked diseases

Answer 19

Males are XY
Females are XX
So males only require 1 recessive allele for it to be expressed whilst females require 2

Question 20

Autosome definition

Answer 20

Any chromosome that is not a sex chromosome

Question 21

Where are autosomal genes located

Answer 21

On the autosomes

Question 22

Why are genes on the same autosome said to be linked

Answer 22

They will not be separated by independent segregation, only can be split up by crossing over.

Question 23

The closer together the 2 genes are on the autosome the more closely they are to be linked because

Answer 23

Crossing over is less likely to split them up

Question 24

Why won’t you obtain expected phenotypic ratio for autosomally linked genes?

Answer 24

The gametes produced will be limited to the pair that are linked. Therefore a higher proportion of offspring will have their parents genotypes

Question 25

What is epistasis

Answer 25

When the allele of 1 gene masks the expression of an allele of a different gene

Question 26

Dihybrid cross with a recessive epistastic allele ratio

Answer 26

9:4:3

Question 27

Dihybrid cross with a dominant epistastic allele ratio

Answer 27

12:3:1

Question 28

What is the null hypothesis

Answer 28

That there’s no significant difference between the observed and expected values

Question 29

If X^2 is larger than the critical value then

Answer 29

There is a significant difference So we reject the null hypothesis

Question 30

If X^2 is smaller than the critical value

Answer 30

There is no significant difference We can accept the null hypothesis

Question 31

Why is Chi Squared used

Answer 31

Categorical data

Question 32

Autosomal linkage exam question when u compare values

Answer 32

Z individual produced mainly GN and gn gametes. Crossing over produces few Gn or gN gametes. So less Ggnn or ggNn individuals

Question 33

Why don’t the X and Y chromosome form the typical bivalent as other chromosomes do

Answer 33

Y and X are different sizes so the chromatids are unable to line up and form the bivalent shape