3.7.1-Inheritance

Question 1

Chromosome

Answer 1

Made of proteins in DNA containing hereditary information which is physically pasted onto the next generation

Question 2

Gene

Answer 2

A length of DNA which codes for a protein

Question 3

Allele

Answer 3

Different farms of a gene

Question 4

Genotype

Answer 4

The genetic constitution of an organism

Question 5

Phenotype

Answer 5

The observable characteristics of an organism resulting from its genotype and interactions with the environment

Question 6

Homozygous

Answer 6

Two alleles of a gene at the same

Question 7

Heterozygous

Answer 7

The two alleles of a gene are different

Question 8

Dominant

Answer 8

The allele is always expressed in the phenotype in absence of a dominant allele or homozygous

Question 9

Recessive

Answer 9

The allele which is only expressed in the phenotype in absence of a dominant allele

Question 10

Mono hybrid

Answer 10

Genetic diagrams involving the inheritance of a single gene

Question 11

Codominance

Answer 11

Both all have an effect on the phenotype of the offspring

Question 12

Sex linkage

Answer 12

Any gene which is carried on the X or Ychromosome is sex linked. May Will only have one all of a sex linked gene.
Females need to be homozygous recessive

Question 13

Dihybrid

Answer 13

The inheritance of two characteristics controlled by two separate genes inherited independently

Question 14

Epistasis

Answer 14

One gene locus masks are suppresses the expression of another gene locus

Question 15

Autosomal

Answer 15

Genes are linked if they are inherited on the same chromosome

Question 16

Null hypothesis

Answer 16

States that there is no significant difference between the observed and expected values

Question 17

Multiple alleles

Answer 17

Genes may have more than two alleles
Only two can be present in one individual

Question 18

Genetic diagram rules

Answer 18

Identify the interaction between alleles
Give alleles symbols
State parents phenotype
State parents genotype
Possible damages for each parent always drawn in circles
Punnet squared to show the random fertilisation of the gametes
Offspring phenotypes linked to the punnet square
Phenotypic ratio

Question 19

Expected ratios and actual observation number of offspring will be different because

Answer 19

Fertilisation of gametes is random
Fusion of Gametes is random
Small population/sample size
Selective advantage/disadvantage to allele
Epistasis/linkage

Question 20

Test cross

Answer 20

Cross the unknown parent with a homozygous recessive organism
Observed the phenotype of the offspring
If any of the offspring show the recessive phenotype, the original plan must be heterozygous
It all offspring are dominant parents must be homozygous

Question 21

Codominance notation

Answer 21

Capital letter represents gene/locus
Superscript the allele
All dominant alleles have own capital letter
Recessive alleles have lowercase letter

Question 22

Pedigree to find dominant allele

Answer 22

Only one parent needs to be carrier for Ali to be inherited
Recessive phenotype shown in offspring, not parent

Question 23

Pedigree to find recessive allele

Answer 23

Both sexes affected
Both parents need to have allele for allele to be inherited by offspring

Question 24

Pedigree to find X-linked allele

Answer 24

More common in male
Parents not showing disease but offspring do

Question 25

Dihybrid inheritance general

Answer 25

Dihybrid crosses involve two genes at two locus onto two chromosomes You inhabit one allele for each gene from each parent You inherit one letter from each gene You have two alleles for each gene For dihybrid crosses, you have four letters in your genotype

Question 26

Common dihybrid phenotypic ratio and reason why

Answer 26

9:3:3:1 Heterozygous at both gene Loki Alleles show complete dominance

Question 27

Three types of epistasis

Answer 27

Add dominant allele at one locus masks the expression of allele at the second locus Homozygous recessive alleles at one locus masks the expression of alleles at the second Two enzymes coded fob by 2 genes act sequential in a metabolic pathway

Question 28

If there is no independent assortment, does this mean that there is more or less genetic variation?

Answer 28

Less

Question 29

Explain the effect of linkage

Answer 29

Alleles are linked State common gametes produced Crossing over Will produce other gametes State other gametes Fewer specific individuals will be produced/ more variation

Question 30

Chi squared

Answer 30

Used to compare expected and observed data

Question 31

Student T test

Answer 31

Used to compare means from two sets of data

Question 32

Correlation coefficient

Answer 32

Used to compare data from different variables that have been sampled

Question 33

What type of data is the Chi squared test used for?

Answer 33

Categorical data

Question 34

Formulae for chi squared

Answer 34

(Sum of (O-E)^2)/E

Question 35

How to find the degrees of freedom

Answer 35

Number of different classes - 1

Question 36

P is greater than 0.05

Answer 36

Accept null hypothesis No significance in data Difference in data due to chance

Question 37

Pay is less than 0.05

Answer 37

Reject null hypothesis Significant difference between Difference in data is not due to chance

Question 38

Population

Answer 38

A group of organisms of the same species that lives in a habitat and can interbreed

Question 39

Gene pool

Answer 39

All the alleles of a gene in a population

Question 40

Allele frequency

Answer 40

The number of times in all occurs in a gene pool

Question 41

Hardy Weinberg

Answer 41

Mathematical model, which project predicts that allele frequencies will not change from generation to generation

Question 42

Assumptions made using hardy-weinburg

Answer 42

Population is very large Mating within population is random No selective advantage/disadvantage for any genotype There are no mutations The population is isolated, so no migration

Question 43

Hardy Weinberg equations

Answer 43

p+q=1 p is dominant q is recessive p^2 + 2pq + q^2 =1 p^2 is homozygous dominant q^2 is homozygous recessive 2pq is heterozygous

Question 44

Approach to hardy-Weinberg questions

Answer 44

Write out both equations Identify which equation must be used Work out q^2 Workout q Workoutp Complete calculation and check answers