Photo-oxidation is
Answer: D
All three descriptions apply to photo-oxidation.
It is the light-driven and oxygen-driven breakdown of a substance, and it covers photorespiration, in which Rubisco fixes oxygen instead of carbon dioxide, and photolysis, the light-driven splitting of water.
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Which among the following blood protein regulates the amount of water in plasma ?
Answer: D
Albumin regulates the water content of plasma.
It is the most abundant plasma protein and exerts most of the colloid osmotic pressure that holds water inside the capillaries. When albumin falls - in liver disease or malnutrition - fluid leaks into the tissues and causes oedema.
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Which one of the following vitamins is known as the anti sterile factor ?
Answer: B
Tocopherol - vitamin E - is called the anti-sterility factor.
Its deficiency causes reproductive failure in laboratory animals, which is how it was discovered in 1922. It is also the body's principal fat-soluble antioxidant, protecting membrane lipids from oxidation.
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Oparin is known for his hypothesis on
Answer: B
Oparin is known for his hypothesis on the origin of life.
He proposed in 1924 that organic molecules formed in the early reducing atmosphere and accumulated in the sea as a 'primordial soup' from which the first living systems arose. Haldane reached the same conclusion independently in 1929.
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Name the blood cells in which nucleus is absent
Answer: B
Blood platelets have no nucleus.
They are not whole cells but fragments budded off from the giant megakaryocytes of the bone marrow, so they carry no nucleus and live only about ten days. Mature red cells likewise lose theirs; all the white cells keep them.
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Branch of science which deal with the study of causative agent of disease is __________
Answer: B
The study of the causes of disease is etiology, from the Greek aitia, cause.
It identifies the agent, whether infective, genetic, nutritional or environmental. Pathology, by contrast, studies the changes the disease produces in the tissues.
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Which component of plants receives stimulus for flowering?
Answer: C
The leaves receive the stimulus for flowering.
They contain the phytochrome that measures the length of the dark period, and produce the flowering signal - florigen, now identified as the FT protein - which travels through the phloem to the shoot tip, where the flower is actually formed.
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Plants synthesise protein from
Answer: D
Plants build protein from amino acids.
They make the amino acids themselves, combining the carbon skeletons from photosynthesis with nitrogen taken up as nitrate. Animals cannot do this for the essential amino acids and must obtain them from food.
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Water is conducted in vascular plant by-
Answer: D
Water is conducted in a vascular plant by the xylem.
Its tracheids and vessels are dead, hollow, lignified cells forming continuous tubes from root to leaf. Water is drawn up them by the pull of transpiration, helped by the cohesion between water molecules. Phloem carries food, in both directions.
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Who is known as father of medicine
Answer: C
Hippocrates is called the father of medicine.
Working on Kos in the fifth century BC, he separated medicine from superstition, insisting that disease has natural causes. The Hippocratic Oath is named after him.
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