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:
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:
Column I | Column II | |
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 |