MUTATIONS

Question 1

Describe albinism

Answer 1

• Marked by the absence of pigment from the hair, skin and eyes.
• The hair of a person with albinism tends to be whitish blond, the skin extremely pale and the eyes pinkish.
• The result of one missing protein.

Question 2

Describe cystic fibrosis

Answer 2

• The mutation occurs in a huge gene on chromosome 7. The gene has the code for 1480 amino acids that make up a protein that regulates the passage of chloride ions across the cell membrane.
• Symptoms: salty-tasting skin, persistent coughing, wheezing.
• RECESSIVE

Question 3

Describe Duchenne Muscular Dystrophy

Answer 3

May arise through a mutation in the mother, which can then be inherited by her sons. The mutation may also occur in a male zygote so that he child develops the disease.
Results in a wasting of the leg muscles and later the arms, shoulders and chest.

Question 4

Describe Tay-Sachs disease.

Answer 4

Disorder of lipid metabolism that is inherited in an AUTOSOMAL RECESSIVE pattern. A lethal recessive condition as the missing enzyme results in the accumulation of a fatty substance in the nervous system.

Question 5

Describe Klinefelter syndrome

Answer 5

Also known as XXY syndrome, it is a genetic donation in which a male is born with an extra copy of the X chromosome.

Question 6

Describe Turner syndrome

Answer 6

A chromosomal disorder in which a female is born with only one X chromosome.

Question 7

Name the different types of chromosomal mutations.

Answer 7

Deletion, translocation, inversion, duplication, non-disjunction.

Question 8

What is deletion?

Answer 8

Part of a chromosome is lost

Question 9

What is duplication?

Answer 9

A section of chromosome occurs twice. May occur if part of a chromatid breaks off and joins onto the wrong chromatid.

Question 10

What is inversion?

Answer 10

Breaks occur in a chromosome and the broken piece joins back in, but the wrong way around. May disrupt the pairing of homologous chromosomes during meiosis.

Question 11

What is translocation?

Answer 11

A part of a chromosome breaks off and is re-joined to the wrong chromosome.

Question 12

What is non-disjunction?

Answer 12

During meiosis, a chromosome pair does not separate and so one daughter cell has an extra chromosome and one daughter cell has one less than the normal number.

Question 13

What is monopsony?

Answer 13

Monopoly is where an individual is missing a chromosome and they have only one copy instead of the normal two.