Biology ยท 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

The largest cell in the human body is the

  1. nerve cell

  2. muscle cell

  3. liver

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

The nerve cell (specifically the motor neuron) is the longest cell in the human body. Other options like liver and kidney are organs or tissues composed of many cells.

Multiple choice

Bacterial cell membrane is made up of

  1. proteins & phospholipids

  2. cellulose

  3. chitin

  4. all of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The bacterial cell membrane is a phospholipid bilayer embedded with various proteins. Cellulose and chitin are structural carbohydrates found in plant cell walls and fungal cell walls, respectively.

Multiple choice

Mitrochondria are found everywhere except in human

  1. adipose cells

  2. erythrocytes

  3. hepatocytes

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

Mature mammalian erythrocytes (red blood cells) lack mitochondria and a nucleus to maximize space for hemoglobin. Other listed cells require mitochondria for energy production.

Multiple choice

A prokaryotic cell lacks

  1. nuclear membrane

  2. nucleolus

  3. membrane bound cell organelle

  4. all of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Prokaryotic cells lack a defined nucleus (and thus a nuclear membrane and nucleolus) and membrane-bound organelles like mitochondria or chloroplasts. Therefore, all the listed items are absent.

Multiple choice

Schleiden & Schwan proposed that

  1. all cells are alike

  2. all cells die

  3. the bodies of plants & animals are made up of units called cells

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

Schleiden and Schwann are credited with formulating the Cell Theory, which states that all living organisms are composed of cells as the basic structural and functional unit.

Multiple choice

Physical basis of heridity is

  1. nucleus

  2. nucleolus

  3. nucleosome

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

Chromosomes contain DNA, which carries genetic information from parents to offspring, making them the physical basis of heredity. The nucleus contains the chromosomes, but the chromosomes themselves are the carriers.

Multiple choice

The biggest cell is

  1. ostrich cell

  2. mycoplasma

  3. hen egg

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

The ostrich egg is the largest single cell in existence.

Multiple choice

Plant cell differs from the animal cell by the

  1. cell wall present in the animal cell

  2. vacuoles small & large in number in the plant cell

  3. cell wall & chloroplast present in the plant cell

  4. presence of chloroplast in the animal cell but the absence of cell wall.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Plant cells are distinguished from animal cells by the presence of a rigid cell wall and chloroplasts for photosynthesis. Animal cells lack both of these structures.

Multiple choice

The main controlling cell organelle is

  1. nucleous

  2. mitochrondria

  3. nucleolous

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

The nucleus acts as the control center of the cell because it contains the genetic material (DNA) that regulates cellular activities. Note: 'nucleous' is a typo for nucleus.

Multiple choice

The folds of the inner membrane of mitochondria are called

  1. cristae

  2. grana

  3. cisterns

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

Mitochondrial cristae are folds of the mitochondrial inner membrane that provide an increase in the surface area. This allows a greater space for processes that happen across this membrane.

Multiple choice

A cell organelle which helps in phosphorylation is

  1. centrioles

  2. nucleous

  3. chromosomes

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

Mitochondria are the sites of oxidative phosphorylation, the process by which ATP is generated in the cell. This is why they are often called the powerhouses of the cell.

Multiple choice

The waste disposal system of the cell is called

  1. lysosomes

  2. golgibodies

  3. vacuoles

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

Lysosomes contain digestive enzymes that break down waste materials, cellular debris, and foreign substances, earning them the title of the cell's waste disposal or recycling system.

Multiple choice

The membrane surrounding the vacuole of a plant cell is called

  1. tonoplast

  2. plasma membrane

  3. nuclear membrane

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

The tonoplast is the specialized membrane that surrounds the central vacuole in plant cells, regulating the passage of ions and molecules between the cytosol and the vacuole.