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How do we control the concentration of urine?

Osmoregulation is the homeostasis of water in the body. It is important that water volumes are kept relatively constant as this influences electrolyte concentrations and cell activity. There are many ways in...
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Answered by Adam B. • Biology tutor
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What does the term "Semi-conservative" mean in relation to DNA?

DNA is a double stranded helix. During DNA replication, the strands are separated from each other (using an enzyme called DNA helicase). The unzipped DNA strands then utilize another enzyme, known as DNA Pol...
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Answered by Catherine A. • Biology tutor
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Explain the role of T-cells in immune response to viral infection

When T cells bind to viral antigens presented by macrophages they undergo mitosis to form 4 distinct cell variants: Memory T cells- remain in the blood stream to initiate a faster immune response upon re-exp...
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Answered by Will S. • Biology tutor
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Explain how FHS and oestrogen illustrate the principle of negative feedback during the menstrual cycle, and explain therefore why oestrogen may be used as a contraceptive.

FHS is released from the anterior pituitary gland in the brain and causes the follicle to develop in the ovary. the developing follicle produces and secretes oestrogen. This release of oestrogen stimulates t...
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Answered by Catrin P. • Biology tutor
4355 Views

Explain how a synapse between two neurons functions

When impulse arrives at pre-synaptic terminal, the depolarisation opens the voltage-gated Ca2+ ion channels. This causes Ca2+ to enter synapse due to differences in concentration. This causes the vesicles to...
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Answered by George B. • Biology tutor
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