D3.2 Inheritance

Question 1

P generation

Answer 1

parent generation

Question 2

F(1) generation

Answer 2

offspring generation

Question 3

Ratio of dominant phenotype prescence in F2 generation

Answer 3

3:1

Question 4

Define alleles

Answer 4

different forms/bases of genes

Question 5

Define homozygous

Answer 5

gene having 2 identical alleles

Question 6

Define heterozygous

Answer 6

gene having 2 different alleles

Question 7

Define genotype

Answer 7

combination of alleles inherited by organisms

Question 8

Define phenotypic plasticity

Answer 8

the ability for the phenotype to be shaped by a combination of the environment and the genotype

Question 9

Phenylketonuria (PKU) (3)

Answer 9

recessive disorder (homozygous recessive)

caused by mutation in gene on chromosome 12

cannot produce enzyme involved in converting amino acid phenylalanine into tyrosine

Question 10

Impact of phenyketonuria (2)

Answer 10

high concentrations of phenylalanine build up in brain

intellectual disability + delayed development

Question 11

Punett square problem steps (4)

Answer 11

assign letter to gene

write phenotype + genotype of parents (a x b)

punett square

genotype + phenotype ratios

Question 12

Define gene pool

Answer 12

all of different genes + alleles present in an interbreeding population of species

Question 13

Where allele for blood types is located (2)

Answer 13

found on chromosome 9

ABO gene

Question 14

How different alleles form different blood types (4)

Answer 14

alleles synthesize own type of enzyme

enzyme catalyses production of specific carbohydrate chain (sugar) on outside of red blood cell

sugars capable of producing immune response (antigens)

O blood type lacks antigens

Question 15

Allele of A blood type (2)

Answer 15

A is dominant allele

IA IA, IA i

Question 16

Allele of B blood type (2)

Answer 16

B is dominant allele

IB IB, IB i

Question 17

Allele of AB blood type (2)

Answer 17

A and B are codominant

IA IB

Question 18

Allele of O blood type (2)

Answer 18

o blood is recessive

i i

Question 19

Define incomplete dominance (2)

Answer 19

when 2 parents with different phenotypes give rise to offspring with intermediary phenotypes

neither allele is dominant

Question 20

Incomplete dominance notation

Answer 20

uppercase + lowercase letter for alleles

Question 21

Codominance notation

Answer 21

uppercase letter for gene + 2 superscript upercase

Question 22

Sex Chromosomes

Answer 22

X chromosome is longer than Y - contains more genes

Y chromosome contains SRY gene –> will develop male-typical characteristics

Question 23

Autosomes

Answer 23

chromosomes that are not sex chromosomes

Question 24

Sex linked traits

Answer 24

traits where allele is present on one sex chromosome (usually X)

Question 25

Haemophillia (3)

Answer 25

sex-linked disease causes body to be unable to clot blood recessive gene on X chromosome

Question 26

Haemophillia notation (2)

Answer 26

normale male: XsuperscriptH Y Haemophillic male: Xsuperscripth Y

Question 27

Pedigree chart notation (2)

Answer 27

unshaded circle = unaffected female shaded circle = affected female

Question 28

Define polygenetic inheritance (2)

Answer 28

a single characteristic being influenced by multiple genes continuous variation

Question 29

Linked genes

Answer 29

genes that are found on the same chromosomes and are close together

Question 30

Unlinked genes

Answer 30

genes that are found on different chromosomes

Question 31

Define an independent assortment (2)

Answer 31

alleles for different genes separates independently of one another forms new combinations of alleles

Question 32

Dihybrid cross (2)

Answer 32

inheritance of two traits/2 pairs of alleles heterozygous individuals will always give expected phenotype ratio of 9:3:3:1