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Scientific Article Notes, Question and answers, June 2013 Unit 5,
by Stafford Valentine Redden (M.Sc.; M.Ed.; M.A.; Ph.D)

Scientific article for use with Question 7
Naked and ugly: The new face of lab rats
1. In a small room in the lab-animal wing of the University…

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SAQ7. Explain why the mole rat populations may be termed as endemic.
This is because all species of mole rats are found in sub-Saharan Africa alone.

SAQ8. Potato contains a lot of starch. Suggest the importance of potato in the diet of mole rats.…

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SAQ20. Melanin is a pigment found in the skin and fur of mammals. Explain the environmental
influence on the phenotype with reference to melanin production.
High exposure to UV radiation stimulates the increased production of Melanocyte Stimulating
Hormone (MSH) and MSH receptor on melanocytes.…

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9. According to this theory, oxygen-containing free radicals damage the molecules of the body, causing Comment [S39]: a highly reactive atom or group
them to deteriorate over time until they stop functioning altogether. This oxidative damage, as it of atoms with an unpaired electron

is known,…

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10. To her surprise, Buffenstein found the opposite: more telltale oxidative damage in 6-month-olds
than in mice of the same age. Remarkably, however, the damage had no obvious impact on their

Keeping in shape
11. Why is this? To find out, Buffenstein took a closer…

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from both mice and humans multiply until they form a single dense layer. At that point, they stop
dividing, halted by a process called contact inhibition. In cancerous tissues, however, the abnormal
cells continue to multiply, piling up and growing out of control.

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a). G1 (First Gap phase): During this stage
there is rapid synthesis of RNA and proteins
and rapid cell growth occurs during this phase.
The cell has only one copy of the genome.

b). Synthesis (S) phase: DNA replication
occurs. The quantity of DNA doubles in…

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25. When Gorbunova and her team began specifically investigating mole rat cells, they were surprised
at how difficult it was to grow the cells in the lab for study. The cells simply refused to replicate once
a certain number of them occupied a space. Other cells,…

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makes transcription factors the largest group of human proteins. The general transcription factors have
been highly conserved in evolution, with the same factors occurring in different organisms from humans
to simple single-cell organisms.
Mammalian hormones are chemical messengers carried by the blood from endocrine glands to…

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32. This finding is particularly significant because the nerve fibres associated with chemical pain are
also involved in post-traumatic pain in people ­ precisely the type of discomfort researchers would Comment [SVR69]: Post-traumatic stress
like to eliminate. "It's OK to have pain sensation to tell you…


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