Biology MCQs
11. Which of the following statements about cell theory is true?
[A] Cell theory does not apply to fungi
[B] Cell theory does not apply to algae
[C] Cell theory does not apply to virus
[D] Cell theory does not apply to microbes
Show Answer
Correct Answer: C [Cell theory does not apply to virus]
Notes:
The classical cell theory was proposed by Theodor Schwann in 1839. Robert Hooke published the book Micrographia in 1665, a book full of illustrations and descriptions of organisms observed under the recently invented microscope. Cell theory does not apply to viruses because it states that all living beings are made up of cells.
12. What is the total number of chromosomes in a normal human being?
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Correct Answer: C [46]
Notes:
In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46, of which 22 pairs, called autosomes, look the same in both males and females.
13. When is reverse transcriptase a useful enzyme?
[A] an RNA virus converts its RNA to DNA
[B] there are no host cells present
[C] nutrients are scarce
[D] spikes are forming in the new virus
Show Answer
Correct Answer: A [an RNA virus converts its RNA to DNA]
Notes:
Reverse transcriptase is a useful enzyme to have when an RNA virus converts its RNA to DNA. Reverse transcriptase converts RNA sequences into cDNA sequences that are capable of being inserted into different regions of the genome.
14. Whooping cough is caused by which of the following?
[A] Bordetella pertussis
[B] Helicobacter pylori
[C] Yersinia pestis
[D] Treponema pallidum
Show Answer
Correct Answer: A [Bordetella pertussis]
Notes:
Pertussis is a respiratory disease commonly known as whooping cough. It is a very contagious disease caused by a type of bacteria called Bordetella pertussis.
15. How many ribosomes are there in eukaryotic cells?
[A] 70S
[B] 60S
[C] 80S
[D] Not specific
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Correct Answer: C [80S]
Notes:
All prokaryotes have 70S (S = Svedberg units) ribosomes whereas eukaryotes have large 80S ribosomes in their cytosol.
16. Which of the following is absent in the phloem of pteridophytes?
[A] Bast fibers
[B] Companion cells
[C] Phloem parenchyma
[D] sieve cells
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Correct Answer: B [Companion cells]
Notes:
Pteridophytes are vascular, spore-forming, non-seed-forming, non-flowering plants. The phloem of pteridophytes does not have companion cells.
17. What are the important nutrients required by the plants?
[A] macronutrients
[B] micronutrients
[C] Both 1 and 2
[D] None of these
Show Answer
Correct Answer: C [Both 1 and 2]
Notes:
Plants require two types of nutrients and they are macronutrients and micronutrients. Macronutrients include nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur. Micronutrients include boron, chlorine, copper, iron, manganese, molybdenum, and zinc.
18. When did the effect of cytokinin first appear?
[A] adding the liquid endosperm of papaya
[B] adding the liquid endosperm of coconuts
[C] adding the liquid endosperm of mango
[D] adding the liquid endosperm of grapes
Show Answer
Correct Answer: B [adding the liquid endosperm of coconuts]
Notes:
The effect of cytokinin was first observed when the addition of liquid endosperm of coconut to developing plant embryos in culture promoted their growth.
19. Which of the following is the formation of male and female gametes?
[A] Gametogenesis
[B] Gamete transfer
[C] Megasporogenesis
[D] Microgametogensis
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Correct Answer: A [Gametogenesis]
Notes:
Gametogenesis is the formation of male and female gametes while Gamete transfer brings the male and female gametes together.
20. What is the meaning of invertebrate from the following?
[A] lacks of backbone
[B] non cartilaginous
[C] bony vertebrates
[D] none of these
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Correct Answer: A [lacks of backbone]
Notes:
An invertebrate is any animal that lacks a vertebral column, or backbone, as opposed to cartilaginous or bony vertebrae.
