SB3j Gene Mutation

Question 1

why is it an advantage to have brown eyes in a hot country?​

Answer 1

the colour brown is a result of a high concentration of melanin in the iris causing more light to be absorbed and less light to be reflected, giving them more protection from the sun

Question 2

what causes mutations?

Answer 2

a mistake in copying DNA during cell division

Question 3

what can mutations cause? 3

Answer 3

~protein to be made incorrectly
~have no effect
~could cause major changes in how the body functions

Question 4

what is malaria?

Answer 4

a serious disease caused by parasites

Question 5

how is malaria spread?

Answer 5

by bites from infected mosquitoes

Question 6

what happens when you get malaria and what are some symptoms?

Answer 6

~malaria parasites enter red blood cells
~cause fever, vomiting
~can be fatal

Question 7

sickle cell allele?

Answer 7

allele that makes someone more resistant to malaria

Question 8

what caused the sickle cell allele?

Answer 8

a genetic mutation that occurred in malaria prone areas many years ago

Question 9

disadvantages of sickle cell allele?

Answer 9

if both parents have the recessive gene the child may be born with sickle cell anaemia

Question 10

is sickle cell allele recessive or dominant?

Answer 10

recessive

Question 11

genome?

Answer 11

all the DNA in a living organism

Question 12

what is the human genome project?

Answer 12

project to map the human genome

Question 13

2 ways in which the information of a human genome can be useful in medicine?

Answer 13

~predict disease
~to target medicines

Question 14

human genome positives?

Answer 14

~identification of new genes
~genes analysed for mutations causing disease
~detailed information about the genome

Question 15

human genome - negatives

Answer 15

~people may be put under pressure to not have children or terminate pregnancy
~may lead to ‘designer babies’ with selection for specific characteristics

Question 16

Explain how mutation can lead to variation in the phenotype. (3 marks)​

Answer 16

mutation can change the DNA base sequence. This causes a change in the amino acid sequence which creates a different protein and this changes the phenotype