Part A-June 2010

CSIR-UGC National Eligibility Test (NET) for Junior Research Fellowship and Lecturer-ship

Some Important Questions Collected from the Memory of Students and Probable Questions and Answers

Previous and Probable (Memory based) Qustions & Answers Paper-1 Part-A June 2010

1. The element present in least amount by weight in human body
1. C             2.  H           3.  N            4.  P
Ans   2   Expln. Refer the simple instant notes. –  Previous Qns. 2009 June(3rd Qn.)
2. Which of the following fact support, “Humans have originated in Africa ?

  1. Fossils of modern-like humans are found in Africa
  2. .Stone tools and other artifacts support African origin
  3. Highest level of genetic variation in DNA
  4. All the above

Ans.  4    Expln.—There are two theories about the origin of modern humans.

a). They arose in one place – Africa and  b) Pre-modern humans migrated from

Africa to become modern humans in other parts of the world. Most evidence points to the first theory because :

    1. Fossils of modern-like humans are found in Africa.
    2. Stone tools and other artifacts support African origin.
    3. DNA studies

Studies of mitochondrial DNA (mt DNA) which occurs only in the cellular organelles called mitochondria, reveal that humans are astonishingly homogeneous, with relatively little genetic variation. In support of an  African origin for Homo sapiens the work of Cann and Wilson has demonstrated  that the highest level of genetic variation in mt.DNA occurs in African populations.       Cont..Refer the simple instant notes.

3. Which of the following is not a polymer ?

1.Vinyl alcohol      2. Polysterene
3. Polyethylene      4. Rubber

Ans. 1

4. In S phase of cell cycle DNA is duplicated, then what happens to chromosome  number?

1. Number remains the same          2. Doubles the number
3. Reduced to half the number        4. Number reduced to one fourth
Ans.  1    Expln.—The series of changes which involve the growth and division of a
cell is called cell cycle. It consists  of two stages, interphase (resting phase)
and M phase (mitotic phase).

The M phase starts with the nuclear division , corresponding to the separation of daughter chromosomes (karyokinesis) and usually ends with division of
cytoplasm (cytokinesis) . The interphase, though called the resting phase, is the time during which the cell is preparing for division by undergoing both cell growth and DNA replication in an orderly manner. The interphase is divided into three further phases:

*    G1 phase (Gap 1)
*    S Phase (Synthesis)
*    G2 phase (Gap 2)

G1 phase corresponds to the interval between mitosis and initiation of DNA replication. During G1 phase the cell is metabolically active and continuously grows but does not replicate its DNA. Cont….. Refer the simple instant notes.

5. Sucrose is formed of
1. Glucose and fructose             2. Glucose and galactose
3. Fructose and mannose           4. Fructose and galactose
Ans. 1

More Questions & Answers Refer Instant Notes