a) rice hybrids
b) red gram hybrids
c) sorghum hybrids
d) groundnut hybrids
2) In crop improvement programme haploids are of great important because they
a) grow better under adverse conditions
b) are useful in the study of meiosis
c) requires only about half the amount of chemical fertilizers compared to diploids
d) give homozygous lines
3) Mexican wheat variety introduced in India was
a) Sonora 64
b) Lerma Rojo 64-A
c) Sonora 63
d) all of these
4) Breeding for disease resistance requires
a) a good source of resistance
b) planned hybridization
c) disease test
d) all of the above
5) Which one is required for protoplastfusion ?
a) treatment with cellulase &pectinase
b) electrofusion or PEG treatment
c) both a & b
d) recombinant DNA technology
6) An economically useful somaclonal variation is
a) short duration sugarcane
b) high protein content in potato
c) leaf hopper resistance in rice
d) all of the above
7) South-East Asia is thought to be centre for the origin of
a) rice
b) rice & sugarcane
c) rice, sugarcane & mango
d) rice, sugarcane, mango & banana
8) Cellular totipotency was demonstrated by
a) Theodore Schwann
b) A.V.Leeuwenhoek
c) F.C. Steward
d) Robert Hooke
9) Indias wheat yield revolution in the 1960s was possible primarily due to
a) hybrid seeds
b) increased chlorophyll content
c) mutations resulting in plant height reduction
d) quantitative trait mutations
10) In maize, hybrid vigours is exploited by
a) inducing mutations
b) bombarding the protoplast with DNA
c) crossing of two inbreed parental lines
d) harvesting seeds from the most productive plants
11) polyploidy leads to rapid formation of new species, because of
a) isolation behavior
b) genetic recombination
c) development of multiple sets of chromosomes
d) mutation therapy
12) The plant material, which is widely used in the preparation of culture medium is
a) Cycas revoluta
b) Cocos nucifera
c) Pinus longifolia
d) Borassus flabellifer
13) In which one of the following combinations ( a-d) of the number of chromosomes is the present day hexaploid wheat correctly represented?
Combination Monosomic Haploid Nullisomic Trisomic
a) 21 28 42 43
b) 7 28 40 42
c) 21 7 42 43
d) 41 21 40 43
14) A major application of embryo culture is in
a) clonal propagation
b) induction of somaclonal variations
c) overcoming hybridization barriers
d) production of embryoids
15) Hybrid vigour is mostly due to
a) heterozygosity
b) homozygosity of pure characters
c) superiority of all the genes
d) mixing up of cyctoplasm of the male with that of female exclusively
16) Anther culture may be used as a technique for producing haploid plants. However , some diploid plants may also be obtained in the process due to
a) fusion of male & vegetative cells
b) development of exine &entine
c) development of another wall cells
d) fusion of male cells
17) Somatic hybridization refers to
a) fusion of male gamete with the egg cell
b) fusion of male gamete with the polar nuclei
c) fusion of protoplasts
d) fusion of male gamete with the antipodals
18) In crop improvement programmes, virus-free clones can be obtained through
a) embryo culture
b) shoot apex culture
c) grafting
d) hybridization
19) Leucaena leucocephala is
a) called subabul
b) a small leguminous tree with edible fruit & seeds
c) a fodder plant as its pods and leaves are consumed by cattle
d) all of the above
20) Mating between two individuals differing in genotype to produce genetic variation is called
a) domestication
b) introduction
c) hybridization
d) mutation
21) In cross fertilized plants, the flowers are first emasculated. Which organ of the plant is removed in this process?
a) ovary
b) ovules
c) stigmas
d) stamens or anthers