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
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
During 'gene cloning', which is called 'gene taxi' ?
Plasmid
Protozoa
Vaccine
Bacterium
A.
Plasmid
Gene taxi refers to a vector or a carrier which is used to transfer genes from one cell to another in a bacterial colony.
Plasmids are double stranded closed DNA molecule capable of self replication, which is present as extra chromosomal structures in the bacterial cells. They are commonly used as vectors to produce recombinant DNA for gene cloning.