to the first bony fishes, placoderms and cartilaginous
fishes.- Assertion : Cro-Magnon is believed to be more
intelligent and cultured than the man of today.Reason : It had a cranial capacity, somewhat more
than ours, being about 1650cc.- Assertion : Random changes in the allele frequencies
of a population, occurring only by chance, constitute
genetic drift.Reason : Two important examples of genetic drift are
founder effect and gene flow.- Assertion : In case of vegetatively propagating plants,
somatic cells produce germ cells.Reason : This is against Weismann’s theory of
continuity of germplasm.- Assertion : Finches of Galapagos Islands influenced
Darwin to think about evolutionary change.
Reason : He called these birds as Darwin’s finches.
Figure Based Questions- Refer to the diagrammatic representation of
evolutionary history of vertebrates and identify the
labelled parts - A, B, C, D, E, F and G.
40. Fill in the blanks using the letters assigned above.
(a) Periods (i) and (ii) belong to coenozoic era,
while (iii) , (iv) , (v) periods belong to mesozoic
era and (vi) , (vii) periods belong to palaeozoic
era.
(b) (i) period is called age of man and herbs, while
(ii) period is called age of dinosaurs and cycads.
(iii) period is called age of mammals, birds,
angiosperms, while (iv) is called age of
amphibians, ferns and coal forests.
SOLUTIOnS
CHAPTER-5 : PRINCIPlES of INHERITANCE AND
vARIATIoN
(a) 2. (c) 3. (b) 4. (b) 5. (b)
(a) 7. (a) 8. (a) 9. (c) 10. (c)
(a) 12. (d) 13. (a) 14. (d) 15. (b)
false. IA and IB express their own types of sugars
not proteins.
false. Pedigree analysis is utilised to trace the
inheritance of a specific trait, abnormality or disease
in multiple generations.
false. Chromosomal aberrations are commonly
observed in cancer cells.
True 20. Tr u e
false. It is caused by substitution of glutamic acid
(Glu) by valine (Val) at the sixth position of beta
globin chain of haemoglobin.
True
23. false. Alleles do not blend although in a few cases
of incomplete dominance an intermediate phenotype
appears. Heterozygotes express dominant phenotype
when there is a complete dominant recessive allele
interaction or both the phenotypes when alleles are
codominant.
24. True
25. false. It was unacceptable to most biologists.
26. A-(iv), B-(i), C-(ii), D-(v), E-(vi), F-(vii), G-(iii)
27. A-(ii, vi), B-(xii, xiii), C-(xi, xiv), D-(i, v), E-(iv, viii),
F-(vii, x), G-(iii, ix)
28.(A) (a) (i) androsperms, (ii) gynosperms, (iii) androsome
(b) (iv) TDF, (v) sixth, (vi) default
(B) Morgan Henking observed during oogenesis
spermatogenesis in a few insects, a structure called Y
X body, which was later named Y X chromosome. It is
an autosome allosome. Presence of one extra copy of
it in a male individual leads to Turner’s Klinefelter’s
syndrome.