Which one of the following classesis not a representative of green-algae?
Chlorophyceae
Charophyceae
Euglenophyceae
Crysophyceae
Usually the activity of the enzymes is optimum at normal body temperature. At about 0C the activity of the enzyme is
minimum
maximum
Both (a) and (b)
None of these
Viral genome incorporated into host DNA is called
prophase
plasmid
prophage
bacteriophage
C.
prophage
After infecting the bacterium, the virus can follow lysogenic cycle in which bacterial DNA is not destroyed, instead the viral DNA is incorporated into it and attached to the bacterial DNA in a specific manner and replicates along with this. Bacteria which carry a provirus are called lysogenic bacteria. In this condition the viral DNA is transmitted to the progeny of bacteria such a virus is known as provirus are prophage.
Given below are four methods (A to D) and their modes of action (1 to 4) in achieving contraception. Select their correct matching from the four options that follow.
Column I | Column II |
A. The Pill | 1. Prevents sperms reaching cervix |
B. Condom | 2. Prevents implantation |
C. Vasectomy | 3. Prevents ovulation |
D. Copper- T | 4. Semen contains no sperms |
A - 3; B - 4; C - 1; D - 2
A - 2; B - 3; C - 1; D - 4
A - 3; B - 1; C - 4; D - 2
A - 4; B - 1; C - 2; D - 3
The crossing of a homozygous tall pea plant and homozygous dwarf pea plant would yield plants in the ratio of
2 tall : 2 dwarf
all heterozygous tall
all homozygous dwarf
one homozygous tall; one homozygous dwarf; two heterozygous tall
The offsprings obtained by mating two pure strains having constrasting characters are called as
mutants
hybrids
F2 - generation
P - generation