Nucleus

Q.

Why is osmosis called a special type of diffusion?

Q.

What are companion cells?

Q. Differentiate between protoplasm, nucleoplasm and cytoplasm.

Q.

Who first described the nucleus as a cell organelle?

Q.

Who discovered the presence of a nucleus in the cell?

Q. Does osmosis occur in a boiled potato? What types of cells are present in a boiled potato? Explain.

Q. Cell organelles like mitochondria are present in bacteria.

1. True
2. False

Q. Which among the following contains cell wall but lacks a well defined nucleus?

1. Cheek cell
2. Rhoeo leaf cell
3. Onion peel cell
4. Bacterial cell

Q.

Mitochondria is absent in

1. Nerve cells

2. Amoeba

3. Plant cells

4. E. coli

Q. Why cell is a basic unit of the life . Explain the types with examples

Q. Which among the following cells cannot self replicate?

1. Red blood cells
2. Muscle cells
3. 
   Bone cells
4. Liver cells

Q.

Match the phenomenon with the images given.

A --- A, C - diffusion, ​B - osmosis​
B --- A, B - diffusion, ​C - osmosis​

Q. Nucleus has a -layered membrane called the nuclear membrane. This membrane has to allow exchange of materials.

1. double
2. single
3. chromosomes
4. pores

Q.

Who discovered the nucleus in the cell?

Q. Give examples of activities for which our body cells need energy.

Q.

What is a nucleus in biology?

Q.

Question 17
Which of these organisms have a cell wall that isn't made of cellulose?

(a) Bacteria
(b) Hydrilla
(c) Mango tree
(d) Cactus

Q. Which among the following cells do not possess a nucleus?

1. Cheek cells in humans
2. RBC in mammals
3. Muscle cells in humans
4. Sieve tube in phloem

Q.

How is chromatin network related to chromosomes? [2 MARKS]

Q. Question 23
Which of the following does not lose their nucleus at maturity?

(a) Companion cells
(b) Red blood cells
(c) Vessel
(d) Sieve tube cells

Q.

Question 23
Which of the following do not lose their nucleus at maturity?

(a) Companion cells
(b) Red blood cells
(c) Vessel
(d) Sieve tube cells

Q. The matrix inside the nucleus in which the chromosomes are embedded is called ___.

1. Nucleoplasm
2. Nucleic acid
3. Cytoplasm
4. Protoplasm

Q. Nucleus is responsible for the cellular division.

1. True
2. False

Q. Give examples of activities for which our body cells need energy.

Q. Nucleus has a -layered membrane called the nuclear membrane. This membrane has to allow exchange of materials.

1. chromosomes
2. single
3. pores
4. double

Q. Which among the following defines osmosis the best?

(a) Movement of water molecules from a region of its higher concentration to a region of lower concentration of water through a semipermeable membrane
(b) Movement of solvent molecules from its higher concentration to a lower concentration
(c) Movement of solvent molecules from a higher concentration to a lower concentration of solution through a permeable membrane
(d) Movement of solute molecules from a lower concentration to a higher concentration of a solution through a semipermeable membrane

Q.

Match the following organelles with their cellular significance; and choose the correct option from the codes.
$\begin{array}{cc}ColumnI& ColumnII\\ i).\text{Ribosome}& a.\text{Steroid synthesis}\\ ii).\text{Smooth ER}& b.\text{Hydrolytic activity}\\ iii).\text{Lysosome}& c.\text{Formation of Spindle Fibres}\\ iv).\text{Centriole}& d.\text{Protein synthesis}\end{array}$

1. i).➡ a., ii).➡ b., iii).➡ c., iv). ➡ d.

2. i).➡ d., ii).➡ a., iii).➡ b., iv). ➡ c.

3. i).➡ c., ii).➡ d., iii).➡ a., iv). ➡ b.

4. i).➡ b., ii).➡ c., iii).➡ d., iv). ➡ a.

Q. Identify the nucleus in the given cell.

1. 
2. 
3. 
4. 

Q. Chromatin is composed of ____________

1. DNA
2. DNA, RNA and proteins
3. DNA and proteins
4. DNA & RNA only

Q. What are the advantages of flexibility of cell membrane?

1. It enables the cell to undergo exocytosis and endocytosis.
2. It makes the cell impermeable.
3. It makes the cell dead.
4. It has no role.