Question

6. Short-answer questions
1. Write a short account of discovery of cells by
Robert Hooke.
2. Name the parts of the nucleus and state the
function of the nucleus.
3. Why is a cell called the basic structural unit of
life?
4. What are plastids? What are the various types
of plastids?
5. List any three points of difference between plant
cell and animal cell.
6. Differentiate between temporary and permanent
slides.​

Answer 1

• The cell was first discovered and named by Robert Hooke in 1665. He remarked that it looked strangely similar to cellula or small rooms which monks inhabited, thus deriving the name. However what Hooke actually saw was the dead cell walls of plant cells (cork) as it appeared under the microscope.

• The nucleus is a spherical-shaped organelle that is present in every eukaryotic cell. The Nucleus is the control centre of eukaryotic cells. It is also responsible for the coordination of genes and gene expression. The structure of the nucleus includes nuclear membrane, chromosomes, nucleoplasm, and nucleolus

• The cell is called the structural and functional unit of life as all living organisms are made up of cells. Cells are also essential for performing various life processes required for sustaining life. Furthermore, cells provide form and structure, process nutrients and convert it into useable energy.

• The plastids contain the pigments which may be of various types. Sometimes pigments are absent. On the basis of presence of pigments, the plastids are of two types: (i) the chromoplasts (chromatophores) having pigment, and (ii) the leucoplasts which are colourless plastids.

• Animal cells do not have a cell wall composed of a cell membrane. A plant cell is enclosed by a hard/rigid cell wall along with the plasma membrane. The animal cell is enclosed by a thin, flexible plasma membrane. The nucleus is present in the plant cell and lies in one side of the cell.

• Permanent slides using a liquid mounting medium are difficult to make and do have to be stored horizontally. Temporary slides: These are made for the purpose of short time observations. After the observation session, they are discarded. In most cases the slides use a liquid mounting medium

hope this helps..... :)

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Answer 2

Answer:

1. The cell was first discovered by Robert Hooke in 1665 .He observed a honey comb maze formed by maze cells in a microscope .He gave the name 'cellulae: which means 'little room' to the cell

2.

• parts of nucleus are :-

a) Nucleoplasm

b) Nucleolus

c) Nuclear envelope

d) Chromatin material

• Functions of Nucleus are:-

a) It is the control unit of cell

b) It control cellular activities and help in cell metabolism

c) It contains the genetic information of the organism

3. Cell is called basic structural unit of life because every organism is made up of cell and it provides structure to every organism

4. Plastds are largest cell organelles of plant cell

Two types of Plastid are

• Chromoplast
• Leucoplast

5. Answered above in picture

6.Permanent slides: these can be stored for a long time, provided that they were properly made. The specimens have to be properly conserved and cut into thin sections before they are mounted on the slide. ... Temporary slides: These are made for the purpose of short time observations.