Biology Times March 19
(AIPMT 2008)
A) Spray with Bordeaux mixture.
B) Control of the insect vector of the disease
pathogen.
C) Use of only disease-free seeds.
D) Use of resistant varieties.
(a) A & D (b) B & C
(c) A & B (d) C & D
- (a) In artificial selection, reproduction of individuals
with desirable traits in a population is done.
- (d) Inbreeding results in increase in the
homozygosity. Therefore, mating of the related
individuals of same breed will increase
homozygosity.
- (d) True breeding is one that, when self-fertilized
only produces offspring with the same traits. True
breeding organisms are genetically identical alleles
for specified traits.
- (b) Auxin & Cytokinin are root and shoot inducing
plant hormones used widely in Plant tissue culture
experiments.
- (c)Interspecific hybridisation in which male and
female animals of two different related species are
mated.
- (c) Mackerel is a marine fish rich in omega-3-fatty
acids.
- (c)Tryptophan is a precursor to neurotransmitters
Serotonin and Melatonin.
8.(d) Pollengrains of many species can germinate
cannot germinate on the stigma of a flower, but
only one pollen tube of the same species grows
into the style.
9.(c) Polyploidy is the phenomenon of occurrence
of more than two sets of chromosomes in the
nucleus of a cell. Polyploidy arises as a result of
total disjunction of chromosomes during mitosis
and meiosis.
10.(c) Ley farming is an agricultural system where the
field is alternately seeded for grain and left fallow
for growing hay or used for pasture.
11.(b) Polyethylene glycol and sodium nitrate are used
for protoplast fusion in somatic hybridisation. This
method reduces cytotoxicity and the frequency of
fusion is very high.
12.(b) Micropropagation is the technique of producing
thousands of plants through tissue culture. In
somatic embryogenesis, embryos are developed
from the somatic cells in tissue culture
13.(a) A plant cell that had its cell wall completely
or partially removed using either mechanical or
enzymatic means.
14.(d) Out breeding is useful in overcoming inbreeding
depression.
15.(b) Pollen tablets are used supplementing agent.
It is rich in Vitamins, Minerals, Proteins, Lipids
and Fatty acids, Enzymes, Carotenoids and
Bioflavonoids. It an antibacterial, antifungal,
antiviral agent that strengthens the capillaries,
reduces inflammation, stimulates the immune
system and lowers cholesterol levels.
16.(d) Germplasm is living tissue from which new
plants can be grown, it can be a seed or another
plant part- a leaf, a piece of stem, pollen or even
just a few cells that can be turned into whole
plant. Germplasm contains the information for a
species ‘Genetic makeup’ a valuable resource of
plant diversity.
17.(b) Green revolution was the notable increase
in cereal-grains production in Mexico, India,
Pakistan, Philippines and other developing
countries in the 1960’s, this resulted in introduction
of hybrid strains of wheat, rice and corn and the
adoption of modern agricultural technologies.
- (a)
19.(b) Bees are pollinators of many of crop species
such as Sunflower, Brassica, apple and pear.
Keeping beehives in crop fields during flowering
period increases pollination efficiency and
improves yield.
20.(d) Polyethylene glycol is used as gene transfer
without a vector; it is commonly used as protoplast
fusion inducing agents commonly known as
chemical fusogens.
- (b) Lampreys and Hag fishes are commonly called
as jawless fishes.
22.(d) Bordeaux mixture is used to control fungal
diseases and no vector is reported for bacterial
blight disease, the use of disease free seeds and
disease resistant varieties can control disease.
