Strategies for Enhancement in Food Reproduction — BIOLOGY STD 12 Science — Question

Which phenomenon gives 2: 1 ratio instead of 3: 1 ratio? Describe with graphical representation.

Name the part of the flower that contributes to fruit formation in strawberry and guava respectively.

Why water is called as ‘Elixir of Life’?

Is there a relationship between the size of an organism and its life span? Give two examples in support of your answer.

List the four different human male accessory ducts.

(i) Provide tissues for human transplants
(ii) Cancer research
(iii) E. coli hygromycin resistant gene
(iv) Supply of factor IX.

Column A: (Transgenic animal)	Column B : (Application)
(a) Transgenic mice	——————
(b) Transgenic cattle	——————
(c) Pig clones	——————
(d) Transgenic fish	——————

The density of a population in a habitat per unit area is measured in different units. Write the unit of measurement against the following:

1. Bacteria.
2. Grass.
3. Banyan.
4. Deer.
5. Fish.

What is puffed up appearance of Idli/ Dosa due to which metabolic pathway is involved in it?

(i) Why DNA replication is called semi-conservative replication?
(ii) Name the scientist who experimentally proved the same.

Mark the odd one in each series.

1. Scrotum, rete testis, Fallopian tube, vas deferens.
2. Ovary, uterus, vagina, ejaculatory duct.
3. Prostate, testis, seminal vesicles, Cowper's gland.
4. Fallopian tubes, vagina, uterus, ovaries.