Carbon dioxide is called green-house gas because it is
Answer: C
Carbon dioxide is a greenhouse gas because it is transparent to sunlight but traps heat.
Incoming solar radiation is short-wave and passes through; the earth re-radiates it as long-wave infrared, which carbon dioxide absorbs and re-emits in all directions, including back to the surface.
Please log in or register to report this question.
Which of the following part modified into pitcher in pitcher plant-
Answer: B
The pitcher of a pitcher plant is a modified leaf.
The lamina forms the pitcher, the petiole its tendril and the leaf apex the lid. Insects that fall in are digested by enzymes in the fluid, supplying the nitrogen the boggy soil cannot.
Please log in or register to report this question.
Which one of the following is a protein fiber?
Answer: C
Silk is a protein fibre, made of fibroin secreted by the silkworm and coated with the protein sericin.
Wool is the other natural protein fibre, made of keratin. Cotton is cellulose, and nylon and polyester are synthetic polymers.
Please log in or register to report this question.
Which of the following diseases is due to an allergic reaction?
Answer: A
Hay fever is an allergic reaction - allergic rhinitis, provoked by pollen.
The immune system treats a harmless protein as a threat, and IgE antibodies trigger mast cells to release histamine, causing the sneezing, running nose and itching eyes.
Please log in or register to report this question.
Human insulin is being commercially produced from a transgenic species of
Answer: C
Human insulin is produced commercially from transgenic Escherichia coli.
The human insulin gene is inserted into a plasmid and the bacteria are cultured in fermenters. Marketed as Humulin from 1982, it was the first genetically engineered medicine, and it replaced the pig and cattle insulin used earlier.
Please log in or register to report this question.
Carcinoma refers to
Answer: A
Carcinoma is a malignant tumour of the skin or of a mucous membrane - that is, of epithelial tissue.
A malignant tumour of connective tissue is a sarcoma, and one of the blood-forming tissue a leukaemia or lymphoma. Carcinomas are much the commonest human cancers.
Please log in or register to report this question.
Starch is an example of-
Answer: A
Starch is a polysaccharide - a polymer of hundreds or thousands of glucose units.
It occurs as amylose, an unbranched chain, and amylopectin, a branched one. It is the storage carbohydrate of plants; glycogen plays the same role in animals.
Please log in or register to report this question.
A fertilized egg is known as-
Answer: D
A fertilised egg is a zygote.
It is diploid, having received one set of chromosomes from each gamete, and it divides repeatedly to form the embryo. Zoospores and conidiospores are asexual spores and involve no fertilisation.
Please log in or register to report this question.
Virus multiplies in
Answer: A
A virus multiplies only in living tissue.
It has no metabolism, no ribosomes and no means of making protein, so it must use a living host cell's machinery. This is why viruses cannot be grown on a culture medium as bacteria are, and are cultured in eggs or cell lines instead.
Please log in or register to report this question.
Which of the following plant only produce seed but not fruit?
Answer: C
Cycas produces seeds but no fruit.
It is a gymnosperm, and the word means naked seed: the ovules sit exposed on a modified leaf with no ovary around them. A fruit is a ripened ovary, so only the angiosperms have one.
Please log in or register to report this question.
