Artificial selection to obtain cows yielding higher milk output represents:

1.	Directional, as it pushes the mean of the character in one direction
2.	Disruptive, as it splits the population into two, one yielding higher output and the other lower output
3.	Stabilizing followed by disruptive, as it stabilizes the population to produce higher-yielding cows
4.	Stabilizing selection, as it stabilizes this character in the population

Select the mismatch:

1. Rhodospirillum - Mycorrhiza

2. Anabaena - Nitrogen fixer

3. Rhizobium - Alfalfa

4. Frankia - Alnus

Good vision depends on adequate intake of carotene rich food. 
Select the best option from the following statements: 
(i) Vitamin A derivatives are formed from carotene 
(ii) The photopigments are embedded in the membrane discs of the inner segment 
(iii) Retinal is a derivative of Vitamin A 
(iv) Retinal is a light absorbing part of all the visual photopigments

1. (i),(iii) and (iv)

2. (i) and (iii)

3. (ii), (iii) and (iv)

4. (i) and (iv)

The DNA fragments separated on an agarose gel can be visualized after staining with:

1. Acetocarmine

2. Aniline blue

3. Ethidium bromide

4. Bromophenol blue

The hepatic portal vein drains blood to the liver from:
1. Stomach
2. Kidneys
3. Intestine
4. Heart

The vascular cambium normally gives rise to:

1. Primary Phloem

2. Secondary xylem

3. Periderm

4. Phelloderm

Thalassemia and sickle cell anaemia are caused due to a problem in globin molecule synthesis. Select the correct statement

1. both are due to a quantitative defect in globin chain synthesis

2. Thalassemia is due to less synthesis of globin molecules

3. Sickle cell anemia is due to a quantitative problem of globin molecules

4. Both are due to a qualitative defect in globin chain synthesis

The genotypes of a husband and Wife are I^AI^B and I^Ai. 
Among the blood types of their children, how many different genotypes and phenotypes are possible?

1. 3 genotypes; 4 phenotypes

2. 4 genotypes; 3 phenotypes

3. 4 genotypes; 4 phenotypes

4. 3 genotypes; 3 phenotypes

Which of the following facilitates opening of stomatal aperture?

1. Decrease in turgidity of guard cells

2. Radial orientation of cellulose microfibrils in the cell wall of guard cells

3. Longitudinal orientation of cellulose microfibrils in the cell wall of guard cells

4. Contraction of outer wall of guard cells

In Bougainvillea thorns are the modifications of:

1. Adventitious root

2. Stem

3. Leaf

4. Stipules