Top answers

Describe the process of DNA replication

In DNA replication, first the hydrogen bonds between the nitrogenous bases are broken catalysed by the enzyme helicase, causing the DNA double helix to unwind and unzip, leaving the nitrogenous bases exposed...
HN
Answered by Helena N. • Biology tutor
15427 Views

Describe the process of phagocytosis and how antigen presentation leads to antibody production (9 marks)

White cell (macrophage/neutrophil) detects bacteria antigen by binding to cell surface receptorsWhite cell engulfs bacteria (this is endocytosis), bacteria is held in a phagosome Lysosomes enter phagosome an...
CR
Answered by Caine R. • Biology tutor
3527 Views

Describe how the body adapts the solute pressure of the blood (thorough its use of ADH) after a person has drank a large volume of water.

Located at the base of the hypothalamus is the pituitary gland which contains osmoreceptor cells that sense the solute potential of the blood and release ADH in response to changes of the solute potential. I...
DD
Answered by Daniel D. • Biology tutor
3239 Views

Describe and explain how the small intestine is adapted for its function?

The small intestine contains microvilli which increase the surface area of the membrane. It also has a rich blood supply, this maintains the concentration gradient. The small intestine has a membrane which i...
UI
Answered by Uma I. • Biology tutor
28475 Views

What are some key components within the cell surface membrane, and what are their functions?

The cell surface membrane is formed of a phospholipid bilayer, in which the hydrophillic phosphate heads point outwards and the hydrophobic tails point inwards. This forms a barrier for large molecules such ...
MK
Answered by Maria K. • Biology tutor
3206 Views