Search our library of Biology A Level questions

Top answers

Biology

A Level

In the process of mitosis, which stages occur? Describe each stage.

Mitosis is a form of cell division that produces genetically identical cells and it includes 4 main stages. Before Mitosis can occur the cell undergoes Interphase, in which DNA and organelles are replicat...

Answered by Holly C. • Biology tutor

8886 Views

How is an action potential (AP) transmitted across a synapse?

As an action potential (AP) arrives at the synaptic knob and depolarises the presynaptic membrane, voltage-gated Ca2+ channels open, allowing the entry of Ca2+ ions, This caues vesicles (membrane-bound or...

Answered by Young C. • Biology tutor

6066 Views

1) Gluconeogenesis 2) Glycogenesis 3) Glycolysis. Which is stimulated by glucagon production? [A] 1, 2, 3 [B]1 [C] 2, 3 [D] 1,2

B is the answer. Glucagon stimulates an increase in blood sugar/ [glucose] Gluco means glucose is the product Glyco mea...

Answered by James M. • Biology tutor

3239 Views

Describe the different levels of protein structure during the production of a protein

Primary Structure: Peptide bonds form between the carboxyl and amino groups of adjacent amino acids, forming a long polypeptide chain.

Answered by Grace T. • Biology tutor

2521 Views

A bacterial infection that cannot be treated with one sort of penicillin can be treated with a different sort. Use your knowledge of enzyme action to explain why the different sort of penicillin is effective in treating the infection.

Penicillin inhibits an enzyme that forms cross links in bacterial cell walls halting bacterial reproduction. Different penicillins have different shapes or structures. The penicillin that is not effective...

Answered by Georgia D. • Biology tutor

5973 Views