Biology

631. The heat treatment applied to milk to stabilize and to remove disease causing bacteria is called as-

1. Pasteurization
2. Fermentation
3. Coagulation
4. Homogenization

Option “1” is correct.
Pasteurization is the heat-treatment process that destroys pathogenic microorganisms in certain foods and beverages. It is named after the French scientist Louis Pasteur. It is used to stabilize and remove disease from milk.
632. Cockroach cannot survive in the water because its respiratory organ is –

1. Gill
2. Trachea
3. Book lung
4. Pulmonary sac

Option “2” is correct.
Cockroach cannot survive in the water because its respiratory organ is trachea.
633. In which part of the cinchona plant quinine occurs naturally?

1. Root
2. Fruit
3. Seed
4. Bark

Option “4” is correct.
Quinine is a major drug used to treat malaria. Quinine is extracted from the bark of Cinchona tree.
634. Red colour in tomato is due to-

1. Capsaicin
2. Lycopene
3. Xanthophyll
4. None of the above

Option “2” is correct.
Lycopene pigment, which is a red color carotene, is responsible for the redness of tomato.
635. The Scientist known as father of genetics is-

1. Johnson
2. G.J. Mendel
3. F.B. Morrison
4. Morgan

Option “2” is correct.
The law of Inheritance was discovered by Gregor Johann Mendel. He is known as the father of genetics.
636. When ants bite, they inject:

1. Glacial acetic acid
2. Methanol
3. Formic acid
4. Stearic acid

Option “3” is correct.
The acid produced by ants is called formic acid. Chemically it is a simple carboxylic acid.
637. Which one of the following is produced through Viticulture :

1. Silk
2. Earthworm
3. Honey
4. Grapes

Option “4” is correct.
Viticulture is the science, production, and study of grapes.
638. Latest ancestor of modern human is-

1. Java man
2. Cro-Magnon man
3. Neanderthal man
4. Peking man

Option “2” is correct.
Cro-Magnon is a common name that has been used to describe the first early modern humans. However, recent research suggests that the physical dimensions of so-called “Cro-magnon” are not sufficiently different from modern humans to warrant a separate designation.
639. Pungency in chillies is due to the present of:

1. Lycopene
2. Capsaicin
3. Carotene
4. Anthocyanin

Option “2” is correct.
Chillies are valued principally for their high pungency and colour. Pungency in chillies is due to the active constituent “Capsaicin” an alkaloid which is extracted from chillies and is used to the medicine.
640. Which one of the following is considered as a cell within a cell ?

1. Ribosome
2. Chloroplast
3. Lysosome
4. Golgi complex

Option “2” is correct.
Chloroplast is considered as cell within a cell because it contains its own DNA. Hence, it is a semiautonomous organelle. It helps in photosynthesis.