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

Match the following:

 
a. ER 1. It is a set of membrane-bounded, fluid-filled vesicles, vacuoles and flattened cisternae.
b. Golgi apparatus 2. It is the part of cell that occurs between the plasma membrane and nuclear envelop.
c. Cytoplasm 3. It is the membraneous network inside the cell enclosing a fluid-filled lumen that almost fills up the intracellular cavity.

  1. a - 3, b - 2, c - 1

  2. a - 1, b - 3, c - 2

  3. a - 1, b - 2, c - 3

  4. a - 2, b - 1, c - 3

  5. a - 3, b - 1, c - 2
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

ER is the membraneous network inside the cell enclosing a fluid-filled lumen that almost fills up the intracellular cavity. Golgi apparatus is a set of membrane-bounded, fluid-filled vesicles, vacuoles and flattened cisternae.

Multiple choice

Which of the following acts as a cytoplasmic inclusion?

  1. Endoplasmic reticulum

  2. Golgi bodies

  3. Ribosomes

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

A small amount of the carbohydrate is always virtually stored in the form of glycogen, which is an insoluble polymer of glucose that can be depolymerised and used rapidly to supply the cell’s energy needs.

Multiple choice

Which of the following is not a characteristic of plant cell walls?

  1. They are found only in the sporophyte phase of life cycle.

  2. Among other compounds, they contain compounds built of simple sugars.

  3. They may contain enzymes that are biologically active.

  4. They often contain strengthening polymers.

  5. A site of active secretion.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Plant cell walls are present in BOTH sporophyte and gametophyte phases of the plant life cycle, not just the sporophyte. This makes option A incorrect and thus the answer to 'which is NOT a characteristic'. Cell walls contain sugar-based compounds (cellulose), can have active enzymes, and contain strengthening polymers (lignin).

Multiple choice

Which of the following statements does not characterise receptors?

  1. They speed up the reactions by chemical messengers.

  2. Many of them are proteins being lying in the cell membrane.

  3. They get attached to the chemical messengers such as neurotransmitters or hormones.

  4. Receptors accomodate a shallow cleft on their surface known as binding site.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The binding site of receptors is analogous to the active site of enzymes. However, no reaction is catalysed. 

Multiple choice

Membranes of which of the following two organelles are contiguous?

  1. Golgi complex and lysosome

  2. Mitochondria and Golgi complex

  3. Endoplasmic reticulum and Golgi complex

  4. Nucleus and endoplasmic reticulum
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Endoplasmic reticulum (ER) is the largest intracellular compartment with an extensive array of interconnecting membrane tubules and cisternae that extend throughout the cell including the nuclear envelope. The outer membrane of nuclear envelope is continuous with that of the ER.

Multiple choice

What is the marker enzyme of Golgi apparatus?

  1. Hexokinase

  2. Galactosyl transferase

  3. Pyruvate kinase

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

Galactosyl transferase (GT) belongs to the glycosyl transferases. In several tissues and cell lines, the enzyme is localised by immunocytochemistry to the two to three trans cisternae of the Golgi complex and thus, may be considered as a specific membrane component of this type of endomembrane. As a consequence, it is the most common Golgi "marker" enzyme in cell fractionation studies.

Multiple choice

Receptor mediated endocytosis from plasma membrane involves which one of the following coat proteins?

  1. Clathrin

  2. SNARE

  3. Arrestin

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

Most of the cases receptor mediated endocytosis from plasma membrane involves clathrin-coated vesicles. Macromolecules bind to cell-surface receptors, accumulate in clathrin-coated pits and enter the cell as a receptor and ligand complexes in clathrin-coated vesicles. Clathrin consists of three copies each of heavy chain and light chain, forming a three-legged structure called a triskelion.

Multiple choice

Mitochondria are energy-converting organelles, which are present in virtually all eukaryotic cells. These are also called semi-autonomous organelles because of the presence of mitochondrial DNA genome, special mitochondrial ribosomes, tRNAs and various enzymes required for the expression of the mitochondrial genes.

Which of the following characteristics is/are true for mitochondria?

  1. Double membrane bound organelle

  2. Inner membrane contains specialised structures called cristae.

  3. Outer membrane contains no transport proteins.

  4. Only 1 and 2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Mitochondria are double membrane bound organelles. It has an outer membrane, an inner membrane and an inter-membrane space. The inner membrane is highly convoluted, forming folds called cristae.