Top answers

Tell me what occurs in the prophase in mitosis.

Prophase The nuclear envelope breaks down exposing the chromatin The chromatin supercoils into chromosomes - can be viewed under the microscopeSpindles starts to form
JG
Answered by Jasleen G. • Biology tutor
2937 Views

(b) In healthy lungs, a gradient is maintained between the concentration of oxygen in the alveoli and the concentration of oxygen in the lung capillaries. (i) Describe how ventilation helps to maintain this difference in oxygen concentration.

Ventilation of the lungs is a mechanism designed to maintain a high concentration of oxygen present in the alveoli. Blood is delivered to the lungs from the heart deoxygenated, meaning the majority of haemog...
Answered by • Biology tutor
12742 Views

How does glycogen act as a source of energy?

Glycogen is an energy storage molecule found in animal cells. It can be found in many different animal cells but is more prevalent in cells with a higher metabolic rate (those which use more energy), such as...
HP
Answered by Henry P. • Biology tutor
13805 Views

Describe the ionic basis of an action potential, and how this is reflected on the cell's membrane potential (6 marks)

At rest (steady state) there is a greater concentration of Na+ ions and a smaller concentration of K+ ions on the outside compared to the inside of the cell, and the membrane potential is about -70mV. Upon d...
KK
5683 Views

What causes the heart to contract?

This type of question requires careful explanation and therefore would need to be broken down into chunks. One of the reasons for this is that it may be completely new concepts for students. My answer to a s...
SR
Answered by Saajan R. • Biology tutor
5689 Views