Top answers

Explain how capillaries are adapted to their function of exchanging substances, giving 3 examples.

Firstly, capillaries are one cell thick and so this makes them very thin. This reduces the diffusion pathway between the capillary and other cells thus allowing efficient diffusion. Secondly, capillaries als...
RC
Answered by Rebecca C. • Biology tutor
20356 Views

What are the key different types of selection?

Directional selection occurs when a phenotype at the extreme end of a distribution is favoured and so over time the distribution shifts in the direction of the favoured phenotype. An example of this is the d...
AC
Answered by Abigail C. • Biology tutor
3130 Views

Describe the synthesis of ATP in oxidative phosphorylation

Oxidative phosphorylation is a critical component of the cell's metabolic pathway, and is responsible for the generation of most of the cell's ATP. Overall, reducing potential in the form of NADH and FADH2, ...
AG
Answered by Alex G. • Biology tutor
3896 Views

Describe the structure of the human gas exchange system and explain how we breath in and out.

The human gas exchange system includes the trachea, the bronchioles and the alveoli. During inhalation (breathing in) the diaphragm contracts and the external intercostal muscles contract. This increases the...
HI
Answered by Hajira I. • Biology tutor
24587 Views

What is a reflex arc and why is it important?

A reflex arc is made up of a receptor (which detects a stimulus), a sensory neurone , a relay neurone , a motor neurone and an effector (which brings about a response). The neurones are not joined to each ot...
JB
Answered by Janella B. • Biology tutor
5384 Views