17.1

Question 1

Genotype

Answer 1

Genetic makeup of an organism

Alleles it contains

Question 2

Phenotype

Answer 2

Observable or biochemical characteristic expressed in organism

Interaction between genotype and environment

Question 3

Gene

Answer 3

length of DNA that is sequence of nucleotide bases that code for particular polypeptide

Question 4

Locus

Answer 4

position of gene on DNA

Question 5

Reasons ratio isn’t expected ratio

Answer 5

-fertilisation of gametes is random

-sex-linkage

-co-dominance

-samples taken from small populations

Question 6

Law of independent assortment

Answer 6

Chromosomes arrange themselves randomly on the equator during meiosis - each fertilisation combination is pure chance

Question 7

Codominance

Answer 7

Both alleles are expressed in phenotype

Question 8

Meiosis producing genetic variation

Answer 8

-crossing over between chromatids creates different combination of alleles

• independent assortment

Question 9

Epistasis

Answer 9

When alleles mask or supress expression of genes at different locus

Question 10

Sex linkage

Answer 10

Characteristics only coded for by genes found on sex chromosomes

Question 11

X-linked disorders more common in men

Answer 11

• X chromosome is much longer than Y so has more genes that don’t have homologous conterpart

-Males only have one copy of X chromosome so are more likely to have recessive phenotype

Question 12

Autosomal linkage

Answer 12

When genes are close together on the same autosome

Question 13

Autosomal linkage unexpected ratio

Answer 13

-more likely to be inherited together in gametes and offspring
-stay together during independent segregation in meiosis 1
-only 2 outcomes(reduced variation)

Question 14

Recombinant genes

Answer 14

Only formed by crossing over in meiosis 1
Have a lower frequency

Question 15

Parental genes

Answer 15

Autosomaly linked genes
Have a higher frequency

Question 16

Chi squared conditions

Answer 16

1- sample size must be large
2- data must be discrete categories
3- only raw counts not %
4- compare experimental results with theoretical ones

Question 17

Chi squared fomula

Answer 17

Chi squared = sum of
(observed numbers - expected number)^2 / expected numbers

Question 18

Significant results

Answer 18

If chi squared is less than critical value

Reject null hypothesis

Question 19

Null hypothesis

Answer 19

There is no significant statistical difference between the observed number and expected number and it is due to chance

Question 20

Non-significant results

Answer 20

If chi is greater or equal to critical value

Accept null hypothesis