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

Which of the following is not a function of nuclear membrane?

  1. It separates the nucleus from cytoplasm.

  2. It provides flexibility to the cell.

  3. It allows the movement of material between the nucleus and cytoplasm.

  4. It contains the genetic material present inside the chromosomes.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Nuclear membrane is the outer membrane of the nucleus that allows the movement of materials between the nucleus and cytoplasm. It does not provide flexibility to the cell.

Multiple choice

In humans, the structure of cells varies from one organ to another. Which of the following cells in the human body have elongated and branched structures?

  1. Muscle cells

  2. Red blood cells

  3. White blood cells

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

Nerve cells have elongated and branched structures. These are specialised cells that are designed to stimulate other cells in the body in order to communicate. Neurons are excitable, which means they function by using electrical stimulation. Through this electrical message, known as an action potential, neurons are able to initiate action in the cells they target.

Multiple choice

Lysosomes are called as the suicidal bags of a cell because they

  1. digest foreign materials entering the cell

  2. contain powerful digestive enzymes

  3. burst and their enzymes digest their own cells

  4. digest the old organelles of their own cells
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Lysosomes are called the suicidal bags of a cell because during accidental injuries, if their own cell gets ruptured or injured, these lysosomes burst out and release their hydrolytic enzymes into the cell. These enzymes digest the worn out cell.

Multiple choice

Why is there no demarcation of dividing and non-dividing regions in animals?

  1. Animals are symmetrical.

  2. Cell growth is uniform in animals.

  3. Movement in animals is uniform.

  4. Most of the tissues are dead in animals.

  5. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Yes, it is correct. Cell growth in animals is more uniform and so, there is no such demarcation of dividing and non-dividing regions in animals.

Multiple choice

The cytoplasm of large neurons turns dark blue due to hematoxylin staining on

  1. golgi apparatus

  2. axon hillock

  3. polyribosomes and rough endoplasmic reticulum

  4. lipofuscin

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

Yes, it is correct. The polyribosomes and rough endoplasmic reticulum turn dark blue with hematoxylin due to the presence of ribonucleic acids. Thus, the cytoplasm of large neurons turns dark blue due to hematoxylin staining on it.

Multiple choice

A 50-years-old woman is diagnosed with an acoustic neuroma that is surgically removed and sent to the pathology laboratory for testing. If the tissue stains positively for glial fibrillary acidic protein (GFAP), then the tumour must have originated from which of the following neural cells?

  1. Oligodendrocytes

  2. Astrocytes

  3. Microglia

  4. Schwann cells

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

Yes, it is correct. Glial fibrillary acid protein (GFAP) is a specific intermediate filament protein.

Multiple choice

The blood-brain barrier can be disrupted in patients with traumatic brain injury, allowing an influx of both positive and negative agents. This disruption can be produced by a loss of continuity between type 1 continuous capillary cells and

  1. pseudopodia of the microglial cells

  2. adherens junctions of the ependymal cells

  3. foot processes of the astrocytes

  4. lateral extensions of the oligodendrocytes

  5. tight junctions of the pia mater cells
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The foot processes of astrocytes and type 1 capillary cells contribute to the blood-brain barrier limiting the transport of materials into the central nervous system.