Adult human RBCs are enucleated. Which of the following statement(s) is/ are the most appropriate explanation for this feature? 
(a) They do not need to reproduce 
(b) They are somatic cells 
(c) They do not metabolize 
(d) All their internal space is available for oxygen transport
1. Only (a)
2. (a),(c) and (d)
3. (b) and (c)
4. Only (d)

Capacitation occurs in:

1. Epididymis

2. Vas deference

3. Female reproductive tract

4. Rete testis

Asymptote in a logistic growth curve is obtained when:

1. K=N

2. K>N

3. K<N

4. The value of 'r' approaches zero

Artificial selection to obtain cows yielding higher milk output represents:

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