Biology · Science General

Cell Biology and Structure

3,221 Questions

Cell biology focuses on the structure and function of cellular organelles. Key topics include cellular respiration, DNA inheritance, and energy production. These fundamental biology concepts are crucial for medical entrance and state service examinations.

Cell organelles functionsCellular respiration sitesDNA and ribosomesAnimal cell structurePlant cell components

Cell Biology and Structure Questions

Multiple choice

Which of the following atoms is most abundant in living organism?

  1. Oxygen

  2. Carbon

  3. Hydrogen

  4. Nitrogen
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Hydrogen is the most abundant atom in living organisms by number, because water (H2O) makes up about 70% of cell mass, and hydrogen is present in almost all organic molecules. Oxygen is second most abundant by atom count, followed by carbon and nitrogen. By mass, oxygen is most abundant.

Multiple choice

Which among the following connective tissue proteins helps various body tissues to resume their shape after stretching or contracting?

  1. Fibrillin-1

  2. Elastin

  3. Fibrillin-2

  4. Fibrillin-3

  5. Elaunin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Elastin is a protein in connective tissue that is elastic and allows many tissues in the body to resume their shape after stretching or contracting. Elastin helps skin to return to its original position when it is poked or pinched.

Multiple choice

Which among the following cells have the potential to live as long as the organism itself?

  1. Osteoblasts

  2. Osteoid

  3. Chondroblast

  4. Osteoclast

  5. Osteocyte
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

An osteocyte, a star-shaped cell, is the most commonly found cell in mature bone, and can live as long as the organism itself. Although osteocytes are relatively inert cells, they are capable of molecular synthesis and modification, as well as transmission of signals over long distances, in a way similar to the nervous system.

Multiple choice

In tissue culture, callus refers to _______ mass of cells.

  1. differentiated

  2. undifferentiated

  3. regular

  4. solidified

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In tissue culture, a callus is an undifferentiated mass of cells that forms from plant tissue explants. These cells have not specialized into specific tissue types (roots, stems, leaves) and can be induced to regenerate into whole plants through different media. This is the opposite of differentiated cells which have specific functions.

Multiple choice

Bacillus is the name given to

  1. rod-shaped bacterium

  2. spherical-shaped bacterium

  3. comma-shaped bacterium

  4. a virus

  5. star-shaped bacterium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bacillus is the name given to rod-shaped bacterium.

Multiple choice

Which of the following correctly describes enrichment medium?

  1. It is a selective medium.

  2. It is a differential medium.

  3. It favours the growth of very small number of desired microbes to detectable limits.

  4. It is a reducing medium and favours the growth of anaerobes.

  5. It is a complex medium.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Enrichment culture medium is used to increase the number of desired type of organisms to detectable limits.

Multiple choice

Capnophiles are the microbes that are grown

  1. at high CO2 concentration

  2. at low CO2 concentration

  3. using CO2 incubators

  4. using CO2-generating packet incubators

  5. Both (3) and (4)
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct answer.

Multiple choice

The term Hyperthermophiles stands for?

  1. Hperthermophiles are also known as extreme thermophiles.

  2. Microbes that can grow at 80 degrees or higher

  3. Organisms living in hot springs associated with volcanic activity

  4. Both the options 1, 2 and 3 are correct

  5. Organisms that grow in sunlit soil
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

True because all the above three options are for hyperthermophiles only

Multiple choice

Which of the following pairs of cell organelles and their functions is correctly matched?

  1. Mitochondrion - It provides and maintains the shape of the cell, and prevents it from drying.

  2. Ribosomes - They are suicidal bags and they help in digestion of foreign, worn out cells and cell organelles.

  3. Plasma membrane - It gives shape to the cell and regulates the transportation of materials in and out of the cells.

  4. Lysosomes - They help in protein synthesis.

  5. Cell wall - It is a network of membranes and provides a large surface area for the life functions to take place.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This option is correct. Plasma membrane gives shape to the cell and regulates the transportation of materials in and out of the cells.

Multiple choice

A major percentage of protoplasm is mainly made up of elements, which are found in the form of chemical compounds. Which of the following elements does not form a part of protoplasm?

  1. Carbohydrates

  2. Proteins

  3. Carbon

  4. Fats

  5. Water
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

99% of protoplasm is mainly made up of elements,  which are found in the form of chemical compounds. Both elements and compounds in the unique combination provide living nature to the protoplasm. Carbohydrates, proteins, fats and water are found in it.