Meiotic division during oogenesis is different from that in spermatogenesis. Explain how and why?

3

(a)

The evolutionary story of moths in England during industrialization reveals, that "evolution is apparently reversible". Clarify this statement.

3

(a)

Comment on the statement that "evolution and natural selection are end result of consequences of some other processes but themselves are not processes.

3

(a)

What could have triggered mass extinction of species in the past?

3

(a)

What does 'red' indicate in the IUCN red list (2004)?

3

(a)

Explain as to how protection of diversity hot spots alone can reduce up to 30% of the current rate of species extinction.

3

(a)

How does species diversity differ from ecological diversity?

3

(a)

Compare the primary structure of nucleic acid and protein

3

(a)

Why was it believed earlier that proteins could be genetic material?

3

(a)

A _______ is the development of seeds from unfertilised female gamete.
B. Parthenocarpy is the development  of______in an unfertilised flower, resulting in a_______
C. Polyembryony is the presence of more than one_______ in the_______
D. There are usually three germ pores in _______and one in _______
E. The anther wall is composed of_______to_______layers. 
F. The flowers producing _______ and _______ with bright _______ attract the insects.
G. Plants with reduced power of _______ reproduction, _______ dormant period of seed or _______ viability are propagated through vegetative reproduction.
H. The integuments of ovule surround the_______all around expect at the apex, leaving a narrow passage, called the _______.
I. The wind-pollinated flowers are generally _______sexual.
J. In many dicots, the reserves in the _______ and consumed by the developing embryo.

3

(a)

List the condition found on the primitive earth.

3

(a)

Correct the following statement giving reasons -
"The mature insulin molecule consists of three short polypeptide chains".

3

(a)

What will you do to get your cow crossed artificially by an exotic bull?

3

(a)

Identify the phenomenon in the following example-
"Sickle cell anaemia is an autosomal recessive trait.It is caused by the substitution of anino acid glutamic acid by valine at the sixth position of the beta globin chain of haemoglobin.This substitution of amino acid occurs due to phenomenon in which the sixth codon of beta globin gene is transformed from GAG to GUG".

3

(a)

Explain why ecological succession will be faster in a forest devastated by fire than on a bare rock? Also, compare succession in case of an abandoned land after floods with that on a bare rock?

3

(a)

In which parts of the body of the hosts do the following events in the life cycle of Plasmodium take place? Name both the body part and the host.
(a) Fertilization   (b) Development of gametocytes   (c) Release of sporozoites  (d) Asexual reproduction.

3

(a)

What are methanogens? Name the animals in which methanogens occur and the role they play there

3

(a)

'Prevention is better than cure'. Comment.

3

(a)

Differentiate the following and give examples of each.
(i) Innate and acquired immunity.
(ii) Active and passive immunity.

3

(a)

In which way have microbes played a major role in controlling diseases caused by harmful bacteria?

3

(a)

While creating and the presence of variation is directionless, natural selection is directional as it is in the context of adaptation.comment

3

(a)

Identify A,B,C and D with reference to gametogenesis in humans in the flow chart given below.

3

(a)

Mention three uses of PCR.

3

(a)

How bacterial cells are made competent to take up DNA?

3

(a)

Draw a labelled sketch of sparged-stirred tank bioreactor. Write its application.

3

(a)