Search our library of Biology A Level questions

Top answers

Biology

A Level

Why is genetic drift important in small populations?

Within a population there is genetic variation between individuals. For example, individuals have different combinations of different alleles, which may or may not be passed onto their offspring. Genetic ...

Answered by Bethany P. • Biology tutor

25927 Views

mRNA is used during translation to form polypeptides. Describe how mRNA is produced in the nucleus of a cell. (6)

The first step in biology is always to make sure you understand and always use specialist biological terms - it's often said you almost learn more vocab in biology A level than you do in French, ...

Answered by Omar E. • Biology tutor

4866 Views

Describe the structure and bonding that contributes to a functional protein.

Translation of an mRNA transcript by ribosomes produces the two-dimensional primary structure – a linear sequence of amino acids held together by

Answered by Edwin J. • Biology tutor

3326 Views

Name 2 forms of epigenetic modification, and explain the effect they have on the genotype.

Acetylation: addition of an acetyl group to a histone molecule. Forces DNA strands apart, allowing easier access for RNA polymerase for transcription. Therefore increases expression of target gene(s) due ...

Answered by Nick G. • Biology tutor

2926 Views

Describe the chemical composition of phospholipids and how they form cell membranes? (10 marks)

Phospholipids are amphipathic molecules i.e. they have a hydrophilic (“water-loving”), polar head end, and a hydrophobic (“water-fearing”), nonpolar tail end (1 mark). The major phospholipids in most anim...

Answered by Akash B. • Biology tutor

7362 Views