Assertion: The nucleus is an integral part of a cell which contains a definite number of chromosomes in each cell of every species.

Reason: Chromosomes carry hereditary units called genes, responsible for transmitting characteristics from parents to offsprings.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Assertion: Leukoplasts are the kind of plastids which do not contain any pigment. They are colourless.

Reason: Leukoplasts do not play any significant role in plants due to the absence of pigments.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Fill in the blanks with suitable words :

1. Inside the nucleus, there is a small, spherical, darker body called …………… .
2. The plastids which do not contain any pigment are called …………… .
3. Cell wall is composed of …………… .
4. …………… contain yellow and red pigments.
5. The process of preparing food by the plants is known as …………… .

Identify the cellular structures with the help of the following clues :

1. It is a colourless, translucent, viscous liquid found between the cell membrane and nuclear membrane.
2. It contains chromosomes.
3. It traps solar energy for the process of photosynthesis.
4. The selectively permeable, thin, delicate and flexible membrane.
5. The hereditary unit which is located on the chromosomes.