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Describe and explain the effect of an increase in muscular activity on the heart rate.

An increase in muscular activity increases the rate of aerobic respiration. As a result, more carbon dioxide is formed in the Krebs cycle and the pH is lowered. This reduction in pH is detected by chemorecep...
SW
Answered by Shauna W. • Biology tutor
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How does speciation occur?

Speciation can be s ympatric (both populations in the s ame place ) or allopatric (populations in different places ). Speciation can result from natural selection and isolation. Natural Selection:1) A new se...
NG
Answered by Nicholas G. • Biology tutor
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Explain the sequence of events that occur in the control of the cardiac cycle.

The sino-atrial node depolarises which causes a wave of excitation to pass through the atria (right prior to left) before reaching the atrio-ventricular node. The wave of excitation causes systole of the atr...
HG
Answered by Hannah G. • Biology tutor
8825 Views

What is the difference between haploid and diploid cells? (2 Marks)

Diploid cells contain 2 sets of chromosomes (23 pairs of chromosomes) e.g. body cells . Haploid cells contain half the amount of chromosomes as diploid cells (only 1 set of chromosomes ) e.g. gametes.
KD
Answered by Katie D. • Biology tutor
24626 Views

Describe the stages of the mitotic cell cycle, explaining the appearance of cells at each stage.

The cell cycle can be broken into two. When the cell is replicating its DNA and preparing for division, it is in interphase . Interphase cells have a nucleus with chromosomes arranged as chromatin. When the ...
HM
Answered by Hannah M. • Biology tutor
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