Mutations And Diseases

Question 1

What is a mutation?

Answer 1

A change in a gene or a chromosome. It can cause a change in a characteristic.

Question 2

Sometimes mutations can be _______, but sometimes mutations can be ________ or even _________.

Answer 2

Harmful
Neutral
Beneficial

Question 3

What was one of the first mutations studied?

Answer 3

In the fruit fly. The normal eye color is red. But a mutant white eye form was discovered. A gene controlling eye color color had suddenly changed. This was due to a change in the DNA base sequence. The gene no longer coded for the production of red eye color. It now coded for white eyes.

Question 4

In albinos a gene controls production of the skin pigment ________. This protects the skin from ultra-violent light. It gives you freckles and suntan. The structure of a gene ________, so it is no longer coded for the production of melanin.

Answer 4

Melanin

Mutates

Question 5

If a pathogen like a bacterium developed a mutation that gave it resistance to an _________. The mutant gene codes for an _______ that breaks down the antibiotic. So the bacterium increases in numbers out-_________non-________ forms.

Answer 5

Antibiotic
Enzyme
Competing
Resistant

Question 6

Gene mutations are usually ________.

Answer 6

Recessive

Question 7

What can cause mutations?

Answer 7

Radiation and some chemicals can cause mutations. Ultra-Violent radiation and gamma rays are the most damaging. Greater the does the greater the chance of mutation

Question 8

Give an example when there was mass doses of radiation.

Answer 8

WW2 When atomic bombs were dropped on Japan. Many babies were born with defects and over a number of years people developed various cancers.

Question 9

How many people are affected with cystic fibrosis?

Answer 9

1 in 2000

Question 10

Effects of cystic fibrosis:

Answer 10

They produce thick sticky mucus. This can block air passages and the tubes that carry digestive juices to the gut. So the child sometimes has difficulty breathing and absorbing food.

Question 11

Treatment for cystic fibrosis:(2)

Answer 11

Chest therapy

Gene therapy- Inhalers are used to spray millions of copies of the correct gene into cells lining the lungs

Question 12

The _______ is a good breeding ground for germs. Sufferers often get __________ and have to be treated with strong antibiotics. Each infection leaves the lung more damaged and the child becomes more ill.

Answer 12

Mucus

Infections

Question 13

Cystic is cause by a _________ allele.

Answer 13

Recessive

Question 14

Huntington’s shows up in 1 in ________. It shows up when the patient is about ___ to ____ years old.

Answer 14

20000
30
40

Question 15

Effects of Huntington’s

Answer 15

The cells of the brain degenerate and the patient makes clumsy and jerky movements. Sufferers become moody and depressed. Their memory is affected and they eventually become totally disabled.

Question 16

Huntington’s is caused by a _______ allele.so only _____ allele is needed to give the disease.

Answer 16

Dominant

One

Question 17

What is sickle cell anaemia?

Answer 17

Inherited disease of the blood in which the red blood cells have formed an S-shape like sickle.

Question 18

Effects of sickle cell:

Answer 18

Red cells have abnormal haemoglobin amusing the shape which makes it hard for the red cells to carry oxygen.

Question 19

Where is sickle cell mostly found?

Answer 19

West Africa

Question 20

Sickle cell is caused by a ________ allele. The child inherits the allele from each parent and is ____________ recessive.

Answer 20

Recessive

Homozygous

Question 21

Advantages of sickle cell:

Answer 21

Being a carrier makes you resistant to malaria.