B13

Question 1

What is a chromosome?

Answer 1

its made up of long molecules of DNA

Question 2

What does DNA stand for?

Answer 2

deoxyribonucleic acid

Question 3

What is DNA?

Answer 3

a polymer which is made up of many repeating units, spiralled into a double helix.

Question 4

What is DNA made from?

Answer 4

a sugar, base and phoshate

Question 5

What is a nucleotide?

Answer 5

the combination of a sugar, a phosphate and a base.

Question 6

What are the bases called?

Answer 6

ATCG

Question 7

What are proteins made from?

Answer 7

amino acids

Question 8

What is a mutation?

Answer 8

a random change in the sequence of bases

Question 9

Sexual reproduction…

Answer 9

requires a male and female sex cells (gametes)

Question 10

How many bases code for an amino acid?

Answer 10

3

Question 11

Benefits of asexual reproduction?

Answer 11

quick and doesn’t need a mate

Question 12

Benefits of sexual reproduction?

Answer 12

they a genetically different

Question 13

How many pairs of chromosomes are in a human cell?

Answer 13

23

Question 14

Haploid…

Answer 14

having half the normal number of chromosomes

Question 15

Diploid…

Answer 15

having the normal number of chromosomes

Question 16

Mitosis…

Answer 16

is used for growth and repair - produces two diploid daughter cells (which are identical to each other and parent cell)

Question 17

Meiosis…

Answer 17

is used to produce a gametes - produces four haploid daughter cells (which are different to each other and to the parent cell)

Question 18

Equation for fertilization =

Answer 18

human sperm + human egg cell = human zygote

Question 19

Alleles…

Answer 19

different versions of the same gene

Question 20

Dominant…

Answer 20

stronger gene (only need 1 alleles to express the characteristics)

Question 21

Recessive…

Answer 21

weaker gene (need both alleles to be the same for characteristics)

Question 22

Heterozygous =

Answer 22

alleles which are different eg Bb

Question 23

Homozygous =

Answer 23

alleles which are the same eg BB

Question 24

Genotype =

Answer 24

the genetic make up of an organism (the combination of alleles eg BB)

Question 25

Phenotype =

Answer 25

the observable characteristics that the organism has eg brown fur

Question 26

XY =

Answer 26

male

Question 27

XX

Answer 27

female

Question 28

Cystic fibrosis =

Answer 28

is a genetic disorder that affects many organs of the body especially the lungs, reproduction system and the dg

Question 29

Causes of Cystic fibrosis =

Answer 29

its caused by a recessive allele so it must be inherited from both parents who are carriers

Question 30

Polydactyly =

Answer 30

is when someone is born with an extra finger or toes

Question 31

Symptoms of Cystic fibrosis =

Answer 31

Thick mucus, difficulty in breathing, chest infections

Question 32

Risks of embryo screening =

Answer 32

miscarriages, unexpected birth, false or negative tests