Heredity

Question 1

What is a chromosome?

Answer 1

A structure in which DNA (and proteins) are organised. Condensed DNA which is wrapped tightly in coils compacted in chromosomes to be stored in the nucleus.

Question 2

What is a gene?

Answer 2

A sequence/section of DNA that codes for a protein

Question 3

What is a karyotype?

Answer 3

A picture of all the types of chromosomes.

Question 4

How many chromosome pairs are there in a human?

Answer 4

23 pairs

Question 5

What is the last chromosome of a human?

Answer 5

A sex chromosome

Question 6

Female chromosome?

Answer 6

xx

Question 7

Male chromosome?

Answer 7

xy

Question 8

What do people have if they have an extra chromosome?

Answer 8

Disorders

Question 9

What things have chromosomes?

Answer 9

All living organisms have chromosomes

Question 10

What do genes control?

Answer 10

Genes control the characteristics of living organisms

Question 11

Genes are carried on what?

Answer 11

chromosomes

Question 12

Chromosomes are in…

Answer 12

Chromosomes are in pairs, one from each parent meaning genes are pairs.

Question 13

Genes are in…

Answer 13

Genes are in pairs

Question 14

What do genes controlling the same characteristics occupy?

Answer 14

Genes controlling the same characteristics occupy identical positions (locus) on corresponding chromosomes.

Question 15

When a dominant gene is written it is written with ….

Answer 15

A capital letter
e.g B

Question 16

Define dominant gene

Answer 16

an allele which masks the effect of the recessive allele, gene

Question 17

Define recessive gene

Answer 17

An allele which its effects are masked by a dominant allele, gene

Question 18

Define allele

Answer 18

Different versions or alternatives of that gene

Question 19

What is BB genotype? - example

Answer 19

Homozygous dominant

Question 20

What is Bb genotype? - example

Answer 20

Heterozygous

Question 21

What is bb genotype? - example

Answer 21

Homozygous recessive

Question 22

Draw a punnet square

Answer 22

You should know if not sure look in book or online

Question 23

What is a punnet square?

Answer 23

A tool which shows the two genotypes two individuals can produce when crossed

Question 24

Define genotype

Answer 24

The combination of alleles or letters

Question 25

Define phenotype

Answer 25

The observable or physiological characteristics of an organism

Question 26

What is the last pair of chromosomes?

Answer 26

Sex chromosome

Question 27

Genotype of type A blood

Answer 27

I^AI^A or I^Ai

Question 28

Genotypes for type B blood

Answer 28

I^BI^B or I^Bi

Question 29

genotypes for AB blood type

Answer 29

I^AI^B

Question 30

genotype for type O blood

Answer 30

ii

Question 31

Is cystic fibrosis recessive or dominant

Answer 31

recessive

Question 32

is achondroplastic dwarfism dominant or recessive?

Answer 32

dominant

Question 33

is albinism recessive or dominant?

Answer 33

recessive

Question 34

is polydactyly dominant or recessive?

Answer 34

dominant

Question 35

is sickle cell anaemia dominant or recessive?

Answer 35

recessive

Question 36

Which of the following genes are alleles : A and A, A and B, B and C, B and b

Answer 36

A and A, B and b

Question 37

what process separates homologous chromosomes?

Answer 37

Meiosis

Question 38

describe genotype: bb

Answer 38

homologous recessive

Question 39

What is the likely ratio of affected children born to parents of whom are heterozygous for cystic fibrosis?

Answer 39

1 affected: 3 normal

Question 40

What phenotype corresponds to genotype: I^AI^O

Answer 40

Blood type A

Question 41

Expected ratio of offspring from a black rabbit (Bb) and a white rabbit (bb)

Answer 41

50: 50

Question 42

Which of the following is a ‘carrier’ genotype for a disease caused by a recessive gene?

nn, NN, Nn

Answer 42

Nn

Question 43

If a child with cystic fibrosis have normal parents, what must the parents be?

Answer 43

‘Carriers’ - heterozygous for cystic fibrosis - Nn