Which one of the following cellular parts is correctly described?
1. | Centrioles - sites for active RNA synthesis |
2. | Ribosomes - those on chloroplasts are larger (80s) while those in the cytoplasm are smaller (70s) |
3. | Lysosomes - optimally active at a pH of about 8.5 |
4. | Thylakoids - flattened membranous sacs forming the grana of chloroplasts |
Cuscuta is an example of:
1. Brood parasitism
2. Predation
3. Endoparasitism
4. Ectoparasitism
The supportive skeletal structures in the human external ears and the nose tip are examples of:
1. Areolar tissue
2. Bone
3. Cartilage
4. Ligament
Given are the following five statements (I - V) for your consideration:
I: | In Equisetum, the female gametophyte is retained on the parent sporophyte |
II: | In Ginkgo, male gametophyte is not independent |
III: | The sporophyte in Marchantia is more developed than that in Polytrichum |
IV: | Sexual reproduction in Volvox is isogamous |
V: | The spores of slime moulds lack cell walls |
How many of the above statements is/are correct?
1. | Three | 2. | Four |
3. | One | 4. | Two |
Identify the molecules (a) and (b) shown below and select the right option giving their source and use.
(I) | |
(II) |
Molecule |
Source |
Use |
|
1. |
(II) Heroin |
Cannabis sativa |
Depressant and slows down body functions |
2. |
(II) Cannabinoid |
Atropa belladonna |
Produces hallucination |
3. |
(I) Morphine |
Papaver somniferum |
Sedative and painkiller |
4. |
(I) Cocaine |
Erythroxylum coca |
Accelerates the transport of dopamine |
The figure below shows three steps (A, B, C) of Polymerase Chain Reaction (PCR). Select the option giving correct identification together with what it represents.
1. | A - Denaturation at a temperature of about 50ºC |
2. | C - Extension in the presence of heat-stable DNA polymerase |
3. | A - Annealing with two sets of primers |
4. | B - Denaturation at a temperature of about 98ºC separating the two DNA strands |
Identify the likely organisms (a), (b), (c), and (d) in the food web shown below:
(a) |
(b) |
(c) |
(d) |
|
1. |
Dog |
Squirrel |
Bat |
Deer |
2. |
Rat |
Dog |
Tortoise |
Crow |
3. |
Squirrel |
Cat |
Rat |
Pigeon |
4. |
Deer |
Rabbit |
Frog |
Rat |
Which one of the following pairs of chemical substances, is correctly categorised?
1. | Pepsin and prolactin - Two digestive enzymes secreted in the stomach |
2. | Troponin and myosin - Complex proteins in striated muscles |
3. | Secretin and rhodopsin - Polypeptide hormones |
4. | Calcitonin and thymosin - Thyroid hormones |
Vernalisation stimulates flowering in:
1. Turmeric
2. Carrot
3. Ginger
4. Zaminkand
The green revolution in India occurred during:
1. 1970s
2. 1980s
3. 1950s
4. 1960s