Biology Answers

State any six different mechanisms how some species decrease the chances of their

mate mating with another individual.

Discuss what happens when an individual with 17 chromosomes mates with an individual of the same species with 16 chromosomes. 

Make use of a neat, annotated schematic representation to discuss the structure and

function of desmosomes.

Pharmaceutical and healthcare companies are very interested in substances that affect the mitochondria and associated energy releasing metabolic pathways. Depending on their effect, such substances may potentially be developed into ‘weight-loss’ drugs or ‘weight-gain’ drugs. Some substances are marketed as nutritional supplements that increase energy levels and enhance athletic performance.

The human hemoglobin is a tetrameric protein of about 64.5 KDa, consisting of two α-

chains and two β-chains tightly bound.

a) Calculate the number of amino acids present in the α-chains

b) What is the length of each β-chain?

c) What is the sum of the length of the two α-chains?

d) Find the length of the tetrameric protein hemoglobin assuming its all an alpha

The human hemoglobin is a tetrameric protein of about 64.5 KDa, consisting of two α-

chains and two β-chains tightly bound.

a) Calculate the number of amino acids present in the α-chains

b) What is the length of each β-chain?

c) What is the sum of the length of the two α-chains?

d) Find the length of the tetrameric protein hemoglobin assuming its all an alpha

Briefly describe the parts of an unmyelinated and a myelinated neurone. State the functions of neurons and neuroglia. (10%- 5 marks for structure of neurones, 5 marks for functions)

Study the polypeptide structuresequence of a β-strand shown below

b)Calculate the weight of the protein in KDa

Lys-Gly-Asp-Trp-Ser-Glu

a)Draw the chemical structure of the polypeptide. Indicate on the structure the

backbone and peptide bonds

c)Calculate the length of the protein.