ib biology SL genetics 3.1

Haemoglobin is made up of how many polypeptide chains?

• 1

• 2

• 3

• 4

What are the units of heredity responsible for influencing our traits (characteristics)?

• proteins

• ribonucleic acid

• genes

• hormones

What is the name of the position occupied by a gene on a chromosome?

• allele

• mutation

• polarity

• locus

The different forms of a gene are known as

• alleles

• antigens

• exact copies

• recessive

A nucleosome

• consist of DNA only

• consists of histone protein only

• consists of DNA and histone protein

• consists of DNA, histone protein and ribosome

Sickle cell anaemia is the result of

• a single RNA mutation

• a single base substitution of DNA

• a three base change in DNA

• a nonsense mutation

The result of the mutation in the HBB gene is that

• valine replaces glutamic acid

• glutamic acid replaces glycine

• glutamic acid replaces valine

• valine replaces glycine

The mutation that occurs in the DNA sequence of the haemoglobin gene is

• Adenine replaces the thymine in GTG

• Thymine replaces adenine in GAG

• Cytosine replaces adenine in GAG

• Guanine replaces thymine in GTG

Which of the following conditions makes a person a carrier of sickle cell anaemia?

• having two normal versions of the HBB gene

• have one normal and one faulty version of the HBB gene

• having two faulty versions of the HBB gene

• having no HBB gene at all

Which one of the following is incorrect about the effects of sickle cell anaemia?

• higher frequency of blood clotting

• irregular blood flow

• lower oxygen carrying capacity

• lower resistance to malaria