11. Which of the following are longest cells of human body?
[A] Epethelial cells
[B] Pancreatic cells
[C] Nerve cells
[D] Epidermal cells
Show Answer
Correct Answer: C [Nerve cells]
Notes:
A neuron or nerve cell is a cell that carries electrical impulses. Neurons are the basic units of the nervous system. Every neuron is made of a cell body (also called a soma), dendrites and an axon. Dendrites and axons are nerve fibers. It is the longest cell of human body.
12. How does a Unicellular Organism reproduce?
[A] Cell reproduction
[B] Cell division
[C] Fragmentation
[D] Cell synthesis
Show Answer
Correct Answer: B [Cell division]
Notes:
Cell division is the process by which a Unicellular Organism reproduce and divides into two or more daughter cells. Cell division usually occurs as part of a larger cell cycle.
13. Which one of the following is a modified stem? (UPSC Prelims 1996)
[A] Carrot
[B] Sweet Potato
[C] Coconut
[D] Potato
Show Answer
Correct Answer: D [Potato]
Notes:
Potato tuber bears buds in small pits known as eyes. Buds develops to branches. Some of the branches become green, erect and leafy stems that grow horizontally underground.
14. Which among the following types of bees does not have commercial importance?
[A] Dammer bee
[B] The little bee
[C] The Indian hive bee
[D] None of the above
Show Answer
Correct Answer: D [None of the above]
Notes:
There are around 20,000 different species of bees in the world but only 7 of them are honeybees. Of them only five of them have commercial importance in India, they are as follows:
1. The rock bee
2. The Indian hive bee
3. The little bee
4. The European bee
5. Dammer bee
15. The most abundant biomolecule on earth is__?
[A] Minerals
[B] Salts
[C] Carbohydrates
[D] Vitamins
Show Answer
Correct Answer: C [Carbohydrates]
Notes:
Carbohydrate is a biomolecule that is found in the most abundance on earth. Carbohydrates are mostly produced by green plant cells, algae and some bacteria.
16. The change from lysogeny to lymph is usually induced by?
[A] ultraviolet light
[B] chemicals
[C] irradiation
[D] all of these
Show Answer
Correct Answer: A [ultraviolet light]
Notes:
The change from lysogeny to lymph is usually induced by ultraviolet light. Lysogeny is a type of life cycle that occurs when a bacteriophage infects certain types of bacteria.
17. Zygotic meiosis is characterized by__?
[A]
Fucus
[B] Funaria
[C] Marchantia
[D] Chlamydomonas
Show Answer
Correct Answer: D [Chlamydomonas]
Notes:
Chlamydomonas is a genus of green algae that includes about 150 species. All these unicellular flagellates are found as “snow algae” in stagnant water and on moist soil, in freshwater, seawater and even ice. A zygotic meiosis is the meiosis of a zygote immediately following the karyotype, which is the fusion of two cell nuclei.
18. Pyrenoids are the center of the formation of__?
[A] Enzymes
[B] Proteins
[C] Fats
[D] Starch
Show Answer
Correct Answer: D [Starch]
Notes:
Pyrenoids are the center of the formation of Starch. Pyrenoids are non-membrane-bound organelles found in the chloroplasts of algae and hornwort plants. It can be seen by light-microscopy.
19. In which of the following colour, rate of photosynthesis is maximum?
[A] Red
[B] Blue
[C] Green
[D] Yellow
Show Answer
Correct Answer: A [Red]
Notes:
The rate of photosynthesis is maximum in red colour and minimum in yellow colour. This happens because in the absorption spectrum, the red and blue colour gets absorbed and the majority of green light gets reflected.
20. Which is the only metal present in chlorophyll?
[A] Sodium
[B] Iron
[C] Magnesium
[D] Cobalt
Show Answer
Correct Answer: C [Magnesium]
Notes:
Chlorophyll or green leaves contain magnesium ions present in the chloroplast of all green plants. Magnesium ion is found in the middle of the porphyrin ring.
