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In humans, cystic fibrosis is caused by a recessive allele, f. A man and a woman are both heterozygous for the cystic fibrosis allele. What is the probability that they will produce a girl who has cystic fibrosis?

The genotype for someone heterozygous for the cystic fibrosis allele would be Ff . Thus the father’s genotype (including sex chromosomes) would be FfXY and the mother’s would be FfXX . In order to work out t...
YM
Answered by Yasmin M. • Biology tutor
6760 Views

What are the main functions of the liver?

The liver has 4 main functions. In detoxification, toxins (poisonous chemicals produced by living cells or organisms) are broken down, often by enzymes found in the liver, for example catalase which breaks d...
AJ
Answered by Abigail J. • Biology tutor
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Describe and explain some of the adaptations xerophytes have against living in extreme dry conditions.

Xerophyte adaptations include: Curled leaves - create a micro-climate of more humid surrounding air, hence less water is lost to the dry surroundings. Small hairs on leaves - slow surrounding air flow, there...
MJ
Answered by Marlon J. • Biology tutor
10863 Views

Describe the function of the enzymes DNA helicase and DNA polymerase.

DNA helicase unwinds DNA by breaking H bonds between DNA strands. DNA polymerase joins adjacent nucleotides by forming phosphodiester bonds between them.
SC
Answered by Susannah C. • Biology tutor
3583 Views

Describe the function of Anti-diuretic Hormone in the maintenance of a constant volume of water in the body.

Anti-diuretic Hormone (ADH) is secreted from the hypothalamus in the brain. If more ADH is produced, it makes the collecting ducts in the nephron of the kidneys, more permeable to water. Therefore, less wate...
VH
Answered by Vinaya H. • Biology tutor
3690 Views