11. How many chromosomes are present in human beings?
[A] 44
[B] 46
[C] 48
[D] 42
Show Answer
Correct Answer: B [46]
Notes:
Human beings have 46 chromosomes in their cells. 22 pairs of autosomes and 2 special chromosomes called sex chromosomes are present.
12. Which of the following statements are correct with respect to homeostasis?
1. Ecosystems are capable of maintaining their state of equilibrium.
2. They cannot regulate their own species structure and functional processes.
Select the correct option from the codes given below:
[A] Only 1
[B] Only 2
[C] Both 1 & 2
[D] Neither 1 & 2
Show Answer
Correct Answer: A [Only 1]
Notes:
Ecosystems are capable of maintaining their own state of equilibrium. They can regulate their own species structure and functional processes. This capacity of ecosystem of self regulation is referred to as homeostasis.
13. Who among the following is considered as the father of microbiology?
[A] Stephen Hales
[B] Antonie Van Leeuwenhoek
[C] Edwin John Butler
[D] Pier Antonio Micheli
Show Answer
Correct Answer: B [Antonie Van Leeuwenhoek]
Notes:
Antoine van Leeuwenhoek used the single-lens microscope he built to make the first observations of bacteria and protozoa. Leeuwenhoek is universally acknowledged as the father of microbiology.
14. What is the term known as a giant growth of algae?
[A] Panic boom
[B] Algal boom
[C] Herbal boom
[D] Patkai boom
Show Answer
Correct Answer: B [Algal boom
]
Notes:
A massive growth or rapid increase in the population of algae in water is known as algal boom.
15. 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.
16. Viral DNA is removed from the host’s chromosomes and the lytic cycle is called which of the following process?
[A] spontaneous induction
[B] inductive infection
[C] resultant induction
[D] spontaneous infection
Show Answer
Correct Answer: A [spontaneous induction]
Notes:
Viral DNA is removed from the host’s chromosomes and the lytic cycle is called spontaneous induction.
17. Which of the following is true about the cell wall of Gram-positive bacteria?
[A] It consists of multiple layers
[B] It is thicker than that associated with gram-negative bacteria
[C] It contains teichoic acids
[D] All of these
Show Answer
Correct Answer: D [All of these]
Notes:
The cell wall of Gram-positive bacteria are: consists of multiple layers, thicker than that associated with gram-negative bacteria and contains teichoic acids.
18. Bryophytes are dependent on water because__?
[A] Archegonium has to remain filled with water for fertilization
[B] Water is essential for fertilization for their homosporous nature
[C] Water is essential for their vegetative propagation
[D] The sperms can easily reach up to egg in the archegonium
Show Answer
Correct Answer: D [The sperms can easily reach up to egg in the archegonium]
Notes:
Bryophytes are dependent on water because the sperms can easily reach up to eggs in the archegonium.
19. What is the arrangement of megaspores in tetrads in gymnosperms?
[A] Decussate
[B] Tetrahedral
[C] Linear
[D] Isobilateral
Show Answer
Correct Answer: C [Linear]
Notes:
These are formed from the mother cells inside the anther. Thus, the tetrad of the megaspore is usually linear.
20. To which family do brown mustard and broccoli belong?
[A] Solanaceae
[B] Fabaceae
[C] Cruciferae
[D] None of these
Show Answer
Correct Answer: C [Cruciferae]
Notes:
Brassicaceae or Cruciferae is a medium-sized family of flowering plants commonly known as the mustard, cruciferous or cabbage family.
