Biology · 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

The outermost cell layer of an organism is ____.

  1. epithelium

  2. elastin

  3. epidermis

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

The epidermis is the outermost layer of cells in multicellular organisms, serving as the protective barrier against environmental factors. It prevents water loss and protects against pathogens. Elastin is a protein, erythrocytes are red blood cells, and epithelium is a broader tissue category.

Multiple choice

The part of the cell which occurs between the plasma membrane and nuclear envelope is called _____.

  1. protoplasm

  2. cytoplasm

  3. chromosome

  4. cellulose
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cytoplasm is the gel-like substance that fills the space between the plasma membrane and nuclear envelope. It contains organelles, cytosol, and various inclusions. Protoplasm refers to all living contents of the cell, chromosome is genetic material, and cellulose is a plant cell wall component.

Multiple choice

The outer boundary of the cell is called ____.

  1. cytoplasm

  2. plasma membrane

  3. protoplasm

  4. nucleus
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The plasma membrane (also called cell membrane) is the outer boundary that separates the cell from its external environment. It controls what enters and exits the cell. Cytoplasm is inside the membrane, protoplasm includes all living contents, and nucleus is the central organelle.

Multiple choice

A cell is made of living substance called _____.

  1. cytoplasm

  2. protoplasm

  3. gene

  4. deoxyribonucleic acid
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Protoplasm is the living substance that makes up a cell, consisting of cytoplasm, nucleus, and other organelles. Cytoplasm is just the gel outside the nucleus, gene is a unit of heredity, and DNA is the genetic material within the nucleus.

Multiple choice

Lessening of the size of a cell, tissue or organ that was once fully developed and of normal size is known as _________.

  1. anemia

  2. atrophy

  3. a deficiency disease

  4. dehydration
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Atrophy is the decrease in size of a cell, tissue, or organ that was previously normal in size, often due to disuse, poor nutrition, or nerve damage. Anemia is a blood disorder, 'a deficiency disease' is too vague, and dehydration is fluid loss - neither describes shrinkage of developed structures.

Multiple choice

Which of the following statements is/are correct? (a) The cytoplasm supports and protects the cell organelles that perform different metabolic functions. (b) The Golgi apparatus consists of stacks of flattened membrane-bound sacs or vesicles, these stacks are called cristae. (c) Animal cells are small, have no cell wall, and have small vacuoles.

  1. only a

  2. only b

  3. only c

  4. both a and c

  5. a, b and c
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Both b and c are correct. b is incorrect. 

Multiple choice

Given below are some functions of cell organelles. Which of these is the function of the inner membrane of mitochondria?

  1. Plays a central role in cellular reproduction

  2. Contains DNA on which genes are present

  3. Site of cellular respiration

  4. The protein synthesizing site of the cell

  5. Storage units in cells
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Mitochondria is the site of cellular respiration in presence of oxygen and ATP formation. This is the correct function of the inner membrane of mitochondria.

Multiple choice

Which of the following cell organelles has the given properties?

Directions: Read these properties carefully and answer the question that follows.
  
1. Found in plant cells only
2. Double membrane bounded structures
3. Do not have cristae but have extra nuclear DNA

  1. Mitochondria

  2. Cytoplasm

  3. Cytosol

  4. Protoplasm

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

This is the correct answer. Plastids are found in plant cells only. They are double membrane bounded structures. They do not have cristae but have extra nuclear DNA. Chromoplasts are colored plastids and leucoplasts are colorless plastids.

Multiple choice

Which of the following statements is incorrect?

  1. The nucleus contains cytoplasms, which are visible as rod-shaped structures, only when the cell is about to divide.

  2. The nuclear membrane has pores, which allow the transfer of material from inside the nucleus to outside.

  3. The functional segments of DNA are called genes.

  4. Rough endoplasmic reticulum has ribosomes on it.

  5. Viruses lack any membranes, and hence do not show characteristics of life until they enter a living body.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Yes, this statement is incorrect, hence the correct answer. The nucleus contains chromosomes, not cytoplasms, which are visible as rod-shaped structures, only when the cell is about to divide. 

Multiple choice

Which of the following organelles is the site for centrioles?

  1. In centrosomes of plant cell only.

  2. In centrosomes of animal cell only.

  3. In centrosomes of plant and animal cells.

  4. In cytoplasm of plant cell only.

  5. In cytoplasm of animal cell only.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Centrioles are found in centrosome of animal cells only. This is the correct option.