Question 1

Question 3Assertion. Iodine solution makes the nucleus more distinct.Reason. Nucleus contains starch which becomes blue-black upon absorbing the iodine solution.Both A and R are True.Both A and R are False.A is True and R is False.A is False and R is True.

Accepted Answer

A is True and R is FalseExplanationIodine solution is a common stain used in microscopy to enhance the visibility of certain cellular structures, including the nucleus.The enhanced visibility of the nucleus with iodine staining is not due to the presence of starch. Instead, iodine binds to various cellular components, including nucleic acids, making the nucleus more visible under a microscope.

Question 2

Question 4Assertion. Cell membrane is freely permeable.Reason. Cell membrane permits free movement of the solutions across the membrane when two solutions of different tonicity are separated through it.Both A and R are True.Both A and R are False.A is True and R is False.A is False and R is True.

Accepted Answer

Both A and R are False.ExplanationA cell membrane is semi-permeable. It selectively allows the passage of some molecules while preventing others. Solutions of different tonicity will result in osmotic movement of water, but not necessarily the free movement of solutes across the membrane.

Question 3

Question 5Assertion. Scattered Golgi body in animal cells are called as 'dictyosomes'.Reason. Plant cells have dictyosomes because the entire central space is occupied by a large vacuole.Both A and R are True.Both A and R are False.A is True and R is False.A is False and R is True.

Accepted Answer

A is False and R is True.ExplanationScattered Golgi body in plant cells are called as 'dictyosomes'. Plant cells have dictyosomes because the entire central space is occupied by a large vacuole. They play a role in cell plate formation during cell division.

Question 4

Question 1Define the following terms:(a) Cell(b) Organelles(c) Cytoplasm(d) Protoplasm(e) Nucleus

Accepted Answer

(a) Cell — Cell is the structural and functional unit of life capable of independent existence. All cells are basically alike in chemical composition and metabolic processes and arise from a pre-existing cell.(b) Organelles — Organelles are specialized and membrane-bound, living structures in a cell concerned with definite functions.(c) Cytoplasm — Cytoplasm is the part of the cell which is inside the cell membrane and outside the nucleus. It is a semi-liquid substance and contains several organelles, each concerned with a specific function.(d) Protoplasm — The living parts of the cell which consist of cytoplasm, nucleus and other living bodies collectively constitute protoplasm or protoplast.(e) Nucleus — Nucleus is a large spherical body lying nearly in the centre of the cytoplasm. It is surrounded by a double layered nuclear membrane with nuclear pores.

Question 5

Question 2Distinguish between the following pairs:(a) Plant cell and animal cell(b) Cell wall and cell membrane(c) Centrosome and chromosome(d) Chloroplast and chromoplast

Accepted Answer

(a) Plant Cell and Animal CellFeaturesPlant cellAnimal cellSizeIt is usually larger in size.It is usually smaller in size.Cell wallIt consists of a definite cell wall made up of cellulose.It lacks a cell wall.VacuolesIt consists of large and prominent vacuoles.It consists of small and temporary vacuoles.CytoplasmIt consists of less dense cytoplasm.It consists of denser and more granular cytoplasm.(b) Cell Wall and Cell MembraneCell WallCell MembraneIt is the outermost covering in plant cells.It is the outermost covering in animal cells.It is non-living and rigid layer.It is thin, flexible and living membrane.It is freely permeable.It is semi-permeable.It is made up of cellulose.It is made up of lipoproteins.(c) Centrosome and ChromosomeCentrosomeChromosomeIt is a clear space of cytoplasm located close to the nucleus.It is a highly coiled structure contained within the nucleus.Usually one centrosome is present per cell.Several chromosomes can be present per cell.It consists of two rod-like structures made of protein tubulin.It consists of DNA coiled around histone protein core.It initiates and regulates cell division.It transfers hereditary characters from parents to offspring.(d) Chloroplast and ChromoplastChloroplastChromoplastIt is green in colour.It is variously coloured.It contains the pigment chlorophyll.It contains pigments such as xanthophyll and carotene.It traps solar energy for photosynthesis.It imparts colour to flowers and fruits.

Cell — The Structural and Functional Unit of Life

Assertion Reason Type

Descriptive Type