11. Which organs have different basic structures, yet present a similarity in appearance and perform analogous functions?
[A] Kidney and liver
[B] Heart and lungs
[C] Wings of a bat and a bird
[D] Brain and spinal cord
Show Answer
Correct Answer: C [Wings of a bat and a bird]
Notes:
This is a unique example of convergent evolution in which organs can serve similar purposes but originate from very different original structures. Wings of a bat and bird serve the same purpose, flight, yet they have different underlying structures, resulting from a different evolutionary path.
12. Which of the following is the reason behind when one enters a dark room; he is not able to see anything but after some time his vision improves? (UPSC Prelims 1983)
[A] The retina of the eye comes forward
[B] The retina of the eye moves backward
[C] The pupil of the eye contracts
[D] The pupil of the eye dilates
Show Answer
Correct Answer: D [The pupil of the eye dilates]
Notes:
Our eyes cannot see everything clearly when we enter a dark room from a bright light. This is due to the reason that in dark room the pupil is large so when we come out in bright light, a large amount of light enters our eyes and we feel glare.
13. Which of the following clearly define Lineage? (UPSC Prelims 1986)
[A] A straight line joining any two points on the globe
[B] The line of descendants of a particular ancestor
[C] The paleolithic age
[D] The linking of genes
Show Answer
Correct Answer: B [The line of descendants of a particular ancestor]
Notes:
A lineage is a single line of descent or linear chain within the tree while a clade is a monophyletic group, containing a single ancestor and all its descendants. Phylogenetic trees are typically created from DNA, RNA or protein sequence data.
14. Which one of the following vitamins is considered to be a hormone? (UPSC Prelims 1994)
[A] A
[B] B
[C] C
[D] D
Show Answer
Correct Answer: D [D]
Notes:
Vitamin D is a hormone the kidneys produce that controls blood calcium concentration and impacts the immune system. It is also known as calcitriol, ergocalciferol, calcidiol and cholecalciferol.
15. The branch of science that deals with the study of the mental faculties of the brain including emotions is known as__?
[A] Phenology
[B] Phycology
[C] Phrenology
[D] Proctology
Show Answer
Correct Answer: C [Phrenology]
Notes:
The branch of science that deals with the study of the mental faculties of the brain including emotions is known as Phrenology.
16. Why don’t diatoms perish quickly?
[A] Because they are Chitinous
[B] because it has siliceous walls
[C] because Diatoms contain saline soil
[D] because their body is impervious to water
Show Answer
Correct Answer: B [because it has siliceous walls]
Notes:
Diatoms are unique among microorganisms in that they have rigid cell walls made of silica, called frustules. These frustules are intricately patterned and provide protection to the diatom cell. The silica frustules are durable and resist decomposition, which helps diatoms to maintain their structural integrity and avoid rapid decay.
17. Which of the following is analogous to mesosome of bacteria?
[A] Mitochondria of eukaryotes
[B] Golgi apparatus of eukaryotes
[C] Lysosomes of eukaryotes
[D] None of these
Show Answer
Correct Answer: A [Mitochondria of eukaryotes]
Notes:
analogous to mesosome of bacteria is Mitochondria of eukaryotes.
18. Which of the following statements regarding algae is incorrect.
[A] Most algae are photosynthetic
[B] Algae can be classified according to their pigments
[C] All algae are filamentous
[D] Spirogyra does not produce zoospores
Show Answer
Correct Answer: C [All algae are filamentous]
Notes:
Most algae are photosynthetic, Algae can be classified according to their pigments and Spirogyra does not produce zoospores.
19. Which of the following is least likely to be found along the beach?
[A] Brown algae
[B] Red algae
[C] Mosses
[D] All the above
Show Answer
Correct Answer: C [Mosses]
Notes:
Mosses usually form dense green clumps or mats, often found in moist or shady places.
20. Most of the gymnosperms have__?
[A] Only antheridia
[B] Both antheridia and archegonia
[C] Archegonia but no antheridia
[D] Both absent
Show Answer
Correct Answer: C [Archegonia but no antheridia]
Notes:
Archegonia is found in bryophytes, pteridophytes and gymnosperms. It occurs in antheridia bryophytes and pteridophytes.
