Biology : Cell : The Unit of Life

A chromosome carrying the centromere at one of the ends is called

• acentric

• submetacentric

• telocentric

• metacentric

Assertion: Specialization ofcells is advantageous for the organism.

Reason : It increases the operational efficiency of an organism.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both the assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both the assertion and reason are false.

Assertion : The number of cells in a multicellular organism is inversely proportional to the size of body.

Reason : All the cells in the biological world are of same size.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both the assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both the assertion and reason are false.

Barr body is found in the cytoplasm during

• interphase in cell of female mammal

• interphase in cell of male mammal

• prophase in cell of female mammal

• prophase in cell of male mammal

Which of these are most widely used in genetic engineering?

• Plastid

• Plasmid

• Mitochondrion

• Ribosome

Assertion : Plasma membrane is exceedingly thin and not visible as a separate layer. 

Reason : It appears merely as a surface layer of cytoplasm.

• If both Assertion and Reason are true and Reason is the correct explantion of Assertion

• If both Assertion and Reason are true and Reason is not the correct explanation of Assertion

• If Assertion is true but Reason is false

• If Assertion is false but Reason is true

Choose the matched ones.

(A) Vibrio - Rod like bacteria

(B) Mesosome - Helps in cell wall formation

(C) Smooth endoplasmic - Synthesis of lipid reticulum

(D) Vacuoles - Rich in hydrolytic enzymes

• (B) and (C) only

• (A) and (D) only

• (A), (B) and (C) only

• (B) and (D) only

• (B) and (D) only

Which of these organelles does not contain ribosomes?

I. Rough endoplasmic reticulum

II. Chloroplast

III. Golgi apparatus

IV. Mitochondria

• I and II only

• I and IV only

• IV only

• III only

• III only

One type of chromosome has middle centromere whereas
the other has a terminal centromere. They are

• Metacentric and acrocentric

• Metacentric and telocentric

• Sub-metacentric and telocentric

• Telocentric and acrocentric

• Telocentric and acrocentric

Which of the following prokaryotic structures has all the below mentioned roles?

i. They help in respiration

ii. They help in cell wall formation

iii. They help in DNA replication

iv. They increase surface area of plasma membrane.

• Chromosome

• Ribosome

• Mesosome

• Lysosome

• Lysosome