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

Cells are small in size because of their outer ____________.

  1. length

  2. volume

  3. surface area

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

Cells are limited in size by their surface area to volume ratio. As a cell grows, its volume increases faster than its surface area, making it difficult to transport enough nutrients and waste across the membrane.

Multiple choice

All organisms are made up of _______.

  1. compounds.

  2. atoms

  3. organs

  4. cells
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cells are the fundamental structural and functional units of all living organisms. While organisms contain atoms and compounds, cells are the specific biological building blocks.

Multiple choice

_____ explains the organization of cells.

  1. Cellular hierarchy

  2. Molecules

  3. Organisms

  4. Substances
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cellular hierarchy describes how cells are organized into tissues, organs, and organ systems to perform complex functions in an organism.

Multiple choice botany water absorption and ascent of sap in plants apoplast and symplastic pathway transport of water in plants water transport

Apoplast is located

  1. Outside the plasma membrane

  2. In the entire cytosol

  3. inside the plasma membrane

  4. In the plastidial content
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In the Apoplast pathway water cannot enter the protoplasm.

It travels through  the space between the cell wall and cell membrane and intercellular spaces.
So the correct answer is 'Outside the plasma membrane'.

Multiple choice biology movement in and out of the cell diffusion across cells diffusion and osmosis inter cellular movement

To initiate cell photosynthesis, salt solution should be 

  1. Isotonic

  2. Hypotonic

  3. Hypertonic

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

(A) An isotonic solution is a solution where there is no net movement of molecules due to equal concentration on both sides of the cell.
(B) Hypotonic solution is a solution where the movement of molecules is from outside to the inside of the cell.
(C) A hypertonic solution is a solution where the movement of molecules is from inside to outside of the cell.
A hypertonic solution is a solution which contains a high concentration of salt.
When the salt solution is the hypertonic solution then water will enter from outer soil inside the cell so that water will be available for photosynthesis.
So, the correct answer is 'Hypertonic'.
Multiple choice bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

Which of the following statements is not correct?

  1. In plant cells, vacuoles are absent.

  2. Vacuole is bounded by a single membrane.

  3. In Amoeba, contractile vacuole is important for excretion.

  4. Flagellum is important for transport of bacteria.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Plant cells typically have large central vacuoles, which are essential for maintaining turgor pressure and storage. Therefore, the statement that vacuoles are absent in plant cells is incorrect.

Multiple choice bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

A higher plant cell covered with cutin and suberin is placed in water. After 15 minutes the cell

  1. Will be killed

  2. Size will increase

  3. Size will remain unchanged

  4. Size will decrease
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Suberin and cutin are complex macromolecules which mainly function as a barrier to movement of water and solutes. Thus if a higher plant cell is covered with cutin and suberin and placed in water then there will not be any change in the size of the cell as cutin and suberin are hard and water repulsive substances. There will not be any exosmosis or endosmosis in such type of cell.

So the correct answer is 'Size will remain unchanged'.

Multiple choice bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

Osmotic pressure of a cell kept in water is chiefly regulated by

  1. Vacuoles

  2. Plastids

  3. Ribosomes

  4. Mitochondria
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Vacuoles are the organelles that store all the extra water and salts that are the basis of creating osmotic pressure in the cell. The vacuole takes up a huge central place in the cell. The solution outside the cell is hypertonic, hypotonic or isotonic with respect to the contents inside the vacuole. Plastids are the centres for photosynthesis, Ribosomes are small granule-like structures that help in protein synthesis whereas mitochondria generate energy for the cell by utilising sugars. 

So the correct answer is 'Vacuoles'.

Multiple choice biology life processes: control and coordination nervous system in animals structure of neuron structure and function of neuron

Presynaptic ending contains 

  1. Mitochondria

  2. Lysosomes

  3. Centrioles

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • The synapse consists of :
1) presynaptic ending that contains neurotransmitters, and supporting cell organelles like mitochondria and endoplasmic reticulum. 
2) postsynaptic ending contains receptor sites for neurotransmitters. and 3)synaptic cleft is the space between the presynaptic and postsynaptic endings.
The function of mitochondria in presynaptic endings is the calcium homeostasis.
  • Hence Presynaptic ending contains Mitochondria.
  • So, the correct answer is 'Mitochondria'.

Multiple choice zoology our health harmful microorganism for humans microbes and diseases categories of diseases

Metabolic reactions tak place

  1. In vitro

  2. In vivo

  3. Both (a) an d(b)

  4. Only in unicellular organisms
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 Metabolic reactions are those chemical reactions through which a complex substance break into smaller molecules and produces the energy which helps in completing the life cycle of an organism. Metabolic reactions can take place in a living system e.g. digestion and respiration in the living organism. metabolic reactions also take place in an isolated cell-free system e.g. reactions take place in the test tube. Metabolic reactions take place in unicellular as well as multicellular organisms.

So, the correct answer is  ' Both (a) an d(b) '