Biology today

16. The new world monkeys possess a narrow nose with closely
    placed and downwardly directed nostrils.


17. Increase in the number of chromosome sets due to coming

together of genome of two or more organisms is called

autopolyploidy.

18. During allopatric speciation a part of population becomes
    geographically isolated from the main population.


19. Gene mutations that involve substitution, deletion or
    insertion of a single nitrogen base, are called point
    mutations.


20. Uranium - lead technique of age determination of fossils

is based on conversion of unstable radioactive nuclei into

stable nuclei over a fixed period of time.

Match The columns

21. Match Column I with Column II.
    Column I Column II
    A. Saltation (i) Oparin
    B. Mesozoic (ii) Pithecanthropus
    C. Jurassic (iii) Age of gymnosperms
    D. Ape man (iv) Hugo de Vries
    E. Abiogenesis (v) Age of Cycads


22. Match Column I with Column II. (There can be more than
    one match for items in Column I)
    Column I Column II
    A. Connecting link (i) Australian Marsupials
    B. Missing link (ii) Prosimians
    C. Adaptive radiation (iii) Ornithorhynchus
    D. Analogous organs (iv) Flippers of Dolphin and
    pectoral fins of shark
    E. Primates (v) Ichthyostega
    (vi) Simians
    (vii) Protopterus
    (viii) Sting of honey bee and
    scorpion
    (ix) Darwin’s finches
    (x) Seymouria

passage Based Questions

23.(A) Complete the given passage with appropriate words or
phrases.
Glucose 6-phosphate dehydrogenase deficiency occurs

as inborn error of (i). It is also called (ii) because (iii)

cause haemolysis in the patients. Antimalarial drugs like

(iv) cause haemolysis in such persons. The haemolysis is

due to production of (v) which is not removed because

of glucose 6-PD deficiency and the result is lack of (vi).

Malarial parasite cannot complete (vii) in glucose 6-PD

deficient patients due to premature death of (viii).

(B) Read the given passage and correct the errors, wherever

present.

Each gorilla somatic cell contains 46 chromosomes. Out of

these chromosomes, 44 are allosomes and 2 are autosomes.

In female XY and in male XX are sex chromosomes. Human

chromosomes are normally taken from Red blood corpuscles

(RBCs) from the peripheral blood. The banding patterns of

chromosomes indicate that all human races such as Asian,

African and European possess different chromosome

number.

Assertion & reason

In each of the following questions, a statement of Assertion

(A) is given and a corresponding statement of Reason (R)

is given just below it. Of the statements, mark the correct

answer as :

(a) if both A and R are true and R is the correct explanation

of A

(b) if both A and R are true but R is not the correct explanation

of A

(c) if A is true but R is false

(d) if both A and R are false.

24. Assertion : Old world monkeys are close to man.
    Reason : They have better developed brain, smaller ear
    pinnae and sensitive finger tips.


25. Assertion : Ichthyostega is regarded as a link between
    the fishes and amphibians.
    Reason : It exhibits characteristics of both reptiles and
    mammals.


26. Assertion : Jurassic period is also called the age of
    amphibians.
    Reason : Amphibians flourished during jurassic period.


27. Assertion : Primitive atmosphere of Earth was reducing
    atmosphere.
    Reason : Hydrogen atoms present in primitive
    atmosphere combined with all oxygen atoms to form
    water, leaving no free oxygen.


28. Assertion : Balanced polymorphism occurs when
    different forms coexist in the same population in a
    stable environment.
    Reason : In humans, the existence of the A, B, AB and
    O blood groups represents balanced polymorphism.