Biology ยท Science General

Cell Biology and Structure

3,062 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

According to cell theory,

  1. all cells have cell walls

  2. cells can arise spontaneously

  3. cell is the basic structural unit of living things

  4. all cells have a nucleus
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cell theory states that all living organisms are composed of one or more cells, and that the cell is the basic structural and functional unit of life.

Multiple choice

Amoeba shows

  1. tissue level of organization

  2. organ level of organization

  3. organ system level of organization

  4. cellular level of organization
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Amoeba is a unicellular organism, meaning it performs all life functions within a single cell. Therefore, it exhibits the cellular level of organization.

Multiple choice

Which cell in human body does not grow in number after a certain age?

  1. Nerve cell

  2. Blood cell

  3. Muscle cell

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

Nerve cells (neurons) in the human body are highly specialized and generally do not undergo mitosis or divide once they reach maturity. Other cell types like blood, bone, and muscle cells retain the capacity for regeneration or repair throughout life.

Multiple choice

Cell sap encloses

  1. air

  2. cytoplasm

  3. water

  4. water with salt and sugar
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cell sap is the fluid found in the central vacuole of a plant cell. It consists of water, dissolved sugars, salts, and other nutrients.

Multiple choice

Which cells are likely to show much lysosomal activity?

  1. Damaged cells

  2. Gland cell

  3. Hair cell

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

Lysosomes contain digestive enzymes used to break down waste materials and cellular debris. Damaged cells require high lysosomal activity to clear out broken components or undergo programmed cell death.

Multiple choice

What makes up 'Protoplasm'?

  1. Cytoplasm + Nucleusplasm

  2. Cytoplasm + Organelles - Cytoplasm

  3. Cytoplasm - Organelles

  4. Cytoplasm - Nucleus + Organelles
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Protoplasm is defined as the living part of the cell, which includes the cytoplasm and the nucleoplasm (the fluid inside the nucleus).

Multiple choice

Which of the following statements are FALSE regarding bacterial cell? P. The bacterial cell wall is composed of cellulose. Q. Endoplasmic reticulum is not found in bacterial cell. R. Mesosomes are site of localisation of respiratory enzymes. S. Pili are used for attachment to surfaces for colonisation of bacteria.

  1. Only P and Q

  2. Only P and R

  3. Only P and S

  4. Only Q and R

  5. Only R and S
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Bacteria are protected by a rigid cell wall composed of peptidoglycans. Fimbriae are used for attachment to surfaces for colonisation while pili are used to transfer genetic material during sexual reproduction of bacteria.

Multiple choice

Which of the following statements is not true about plasma membrane?

  1. It is the outermost covering of the cell that separates the contents of the cell from its external environment.

  2. It provides shape to the cell.

  3. It is a selectivity permeable membrane.

  4. It is made up of lipids and proteins only.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

While the plasma membrane is made of lipids and proteins, it also contains carbohydrates (as glycoproteins or glycolipids), making the statement that it is made of lipids and proteins 'only' incorrect.

Multiple choice

Which of the following statements is not true according to the cell theory?

  1. All the living organisms are made up of cells.

  2. Cell is the basic unit of life.

  3. Cells contain components called organellae.

  4. Cells arise from pre-existing cells.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The cell theory states that all living organisms are made of cells, the cell is the basic unit of life, and cells arise from pre-existing cells. The presence of organelles is a feature of eukaryotic cells, not a core tenet of cell theory.

Multiple choice

Which of the following statements is not true for nucleus?

  1. It is covered by a double membrane structure.

  2. It has chloroplasts.

  3. It contains DNA.

  4. It plays a key role in cell reproduction.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Chloroplasts are organelles found in the cytoplasm of plant cells, not within the nucleus.