Cell Biology MCQ question and answer with solution | Biology Gk MCQs

The plasma membrane is the living boundary of all cells and in some organisms it is externally covered by a cell wall.

In plant cells, the plasma membrane is surrounded by a cellulose cell wall that provides rigidity and protection.

In bacterial cells, the plasma membrane is covered by a peptidoglycan cell wall which maintains cell shape and prevents bursting.

In fungi and algae, the plasma membrane is also covered by a cell wall made of chitin (fungi) or cellulose (algae).

Therefore, the plasma membrane is covered by a cell wall in plants, bacteria, fungi, and algae, making All of the above the correct answer.

Explanation:
Let's break down what interphase is and its different parts.

Interphase is like the preparation stage for a cell before it divides.
It's a long period of growth and activity where the cell gets ready for cell division.

Interphase has three main phases:
G1 phase: This is the first gap phase. The cell grows in size and produces proteins and organelles.
S phase: This is the synthetic phase. The cell duplicates its DNA (DNA replication).
G2 phase: This is the second gap phase. The cell continues to grow and makes more proteins and organelles needed for cell division.

M phase: This is the mitotic phase or cell division phase. (Not part of interphase)

So, the first part of interphase is the G1 phase.
Correct Answer: B

The nucleolus is a dense, spherical structure found within the nucleus of eukaryotic cells.

It was first observed and described by Fontana in 1781, making him the earliest known scientist to recognize this sub-nuclear body.

Robert Hooke is known for discovering cells using a microscope and coining the term "cell".

Stelly and Feldherr are associated with later studies in cell biology but not with the discovery of the nucleolus.

Hence, Fontana is credited with the first recognition of the nucleolus.

Option A: chloroplast
Chloroplasts are organelles found only in plant cells and some algae.
They are responsible for photosynthesis, the process of converting sunlight into energy.
Animal cells do not have chloroplasts, as they obtain energy by consuming food.

Option B: cell wall
Plant cells have a rigid cell wall made of cellulose that surrounds the cell membrane.
This cell wall provides support, protection, and shape to the plant cell.
Animal cells do not have a cell wall.

Option C: cell membrane
Both plant and animal cells have a cell membrane.
The cell membrane is a thin layer that surrounds the cell and controls what enters and exits.
So, this is NOT a difference.

Option D: nucleus
Both plant and animal cells have a nucleus.
The nucleus contains the cell's genetic material (DNA) and controls the cell's activities.
So, this is NOT a difference.

Therefore, the things that make a plant cell different from an animal cell are chloroplasts and cell wall.