Of the following, which mechanisms are important in the death of erythrocytes (pron:eh-rith-reh-sites) in human blood? Is it
Answer: D
All three mechanisms destroy red cells.
Most are engulfed by macrophages in the spleen and liver - phagocytosis. Some rupture in the circulation, which is haemolysis, and some are damaged mechanically forcing through narrow capillaries. A red cell lives about 120 days.
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Who invented Insulin
Answer: B
Frederick Banting, with Charles Best, discovered insulin at Toronto in 1921.
They extracted it from dog pancreas and showed it controlled blood sugar, first in dogs and then in a fourteen-year-old patient. Banting shared the 1923 Nobel Prize and sold the patent for a dollar.
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Hardest Part of the Human Body?
Answer: A
Tooth enamel is the hardest substance in the body.
It is about 96 per cent mineral, mostly hydroxyapatite crystals packed into rods, and rates 5 on the Mohs scale. Being acellular it cannot repair itself, which is why a cavity never heals.
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Vivipary is defined as germination
Answer: B
Vivipary is germination of the seed while it is still on the parent plant, within the fruit.
Mangroves show it: the seedling develops a long pointed radicle and drops into the mud already rooted, an adaptation to soil that is waterlogged and saline.
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Which of the following tests helps in diagnosis of cancer ?
Answer: A
A biopsy diagnoses cancer.
A sample of the suspect tissue is removed and examined microscopically; only the appearance of the cells themselves can confirm malignancy and grade it. Blood and urine tests may suggest a cancer but cannot establish it.
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When during the Cell Cycle are Chromosomes visible?
Answer: B
Chromosomes are visible only during cell division.
Through interphase the DNA is dispersed as fine chromatin, too thin to resolve. It condenses at prophase into the compact rod-like chromosomes that can be seen and counted, and disperses again at telophase.
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Quinine is extracted from the bark of :
Answer: D
Quinine is extracted from the bark of the cinchona tree.
It was the first effective treatment for malaria and was in use from the seventeenth century, when Jesuit missionaries brought the bark from Peru. India grows cinchona in the Nilgiris and Darjeeling.
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Osmosis is the flow of solution from higher concentration to a solution of lower concentration through a semi permeable membrane. What is incorrect in this statement?
Answer: C
The statement is wrong because a solution does not flow through a semipermeable membrane - only the solvent does.
Osmosis is the movement of solvent, not solution, and it runs from the region of lower solute concentration to the higher. The membrane holds the solute back, which is the whole point.
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The insects do not have blood pigments because
Answer: B
Insects have no blood pigment because their blood has no respiratory function.
Oxygen reaches the tissues directly through a branching system of air tubes, the tracheae, which open at the spiracles. The haemolymph carries food and waste but no oxygen, so it needs no carrier.
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What do genes code for?
Answer: A
Genes code for proteins.
The DNA sequence is transcribed into messenger RNA and translated at the ribosome into a chain of amino acids, three bases specifying each amino acid. Some genes code instead for functional RNAs, but the classical gene specifies a protein.
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