Class Notes NCERT Solutions for CBSE Students
Question: What is membrane bio-genesis?
Answer: The endoplasmic reticulum helps in the manufacture of proteins and fat molecules or lipids which are important for the cell function. These proteins and lipids help in the building of the cell membrane. This process is known as membrane bio-genesis.
Question: Which organelle is known as powerhouse of the cell?
Answer: Mitochondria is known as powerhouse of the cell because they store energy in the form of ATP. [Adenosine Triphosphate]
Question: What are genes?
Answer: Gene is a segment of DNA. They are located on chromosomes in linear fashions. One gene may perform one or more function. Genes are carrier of genetic codes.
Question: Draw various cells of human body.
Answer:
Question; Give five points of differences between prokaryotic cell and eukaryotic cell.
Answer:
Characters
Prokaryotic Cell
Eukaryotic Cell
1. Sise
0.5-5 µm diameter.
Diameter 1 µm-40 µm.
2. Nucleus
No true nucleus, single chromosomes, nuclear membrane absent.
True nucleus, nuclear membrane is present, more than one chromosome in present.
3. Organelles
Membrane-bound organelles are absent.
Membrane-bound organelles are present.
4. Ribosomes
Ribosomes are 70s and randomly scattered.
Ribosomes are 80s, can be free or attached to ER.
5. Cell division
Cell divides by simple fission.
Cell divides by mitosis or by meosis.
Question: Draw a neat labelled diagram of plant cell and label its parts.
Answer:
Question: Draw a neat labelled diagram of animal cell.
Answer:
Question: Name the cell organelle for the following:
- Present only in plant cell, provides strength and rigidity to the cell.
- It is the site for lipids synthesis and helps in detoxification of drugs.
- The inner membrane is folded to form cristae, it has its own DNA and proteins.
- It helps in the formation of lysosomes.
- It imparts colour to the fruit and flowers.
Answer:
- Cell wall
- Smooth endoplasmic reticulum
- Mitochondria
- Golgi apparatus
- Chromoplast
