Biology M.C.Q (1 Marks)

Reduction in BOD

A.1& 5; 5 &1

Rapid divergence of traits among populations inhabiting a given geographical area.

5´ UAACGG 3´

(i) and (ii)

present in the medium and it binds to the repressor.

B. 4000 bp/s
It completes replication process in 18 minutes i.e. 18x 60 seconds.
Rate of polymerization = 4.6 x 106 bp/ 18x 60 s
= 460000/108
= 4259.1bp/s or approximately 4000 bp/sec Thus, the correct option is B.

B. CGTA

A. 23%
According to Chargaff’s rules, in DNA, A =T and G=C;
Thus, A +T+G+C =100
Given T = 27% so A=T =27%
Thus A+T = 27 +27 =54%
Thus, G+C =100 – 54 = 46%
Since G = C so G = 46/2 =23%

B. 2000
Formation of one seed requires fertilsation between one pollen grain and one egg. To produce 1600 seeds, 1600 pollen grains and 1600 eggs will be required. Each microspore mother cell results in the formation of 4 pollen grains after one cycle of meiotic division. So, 400 meiotic divisions will result in the production of 1600 pollen grains. One megaspore mother cell after one cycle of meiotic division results in the formation of 1 egg; so, 1600 meiotic divisions will take place to form 1600 eggs. Thus, total number of meiotic divisions required for the formation of 1600 seeds will be 400 + 1600 =2000.

Both placenta as well as fully developed foetus.