Selina solutions concise biology class 9 icse Solutions for Chapter 2 cell the unit of life

What is the maximum magnification that can usually be achieved by (i) A compound microscope, (ii) An electron microscope?

Name the following:

(i) Any two one-celled organisms.

(ii) The longest cells in the animals.

(iii)Amoeboid cells in humans.

(iv)Shape of white blood cells.

(v) A cell component which is visible only in cell division stages.

Differentiate between (i) an organ and an organelle (ii) a plant cell and an animal cell pertaining to the presence of plastids.

Mention if the following statements are true or false. If false, suggest the change in the information underlined.

(i) Prokaryotic cells have larger ribosomes.

(ii) Eukaryotic cells have mitochondria.

(iii) Amoeba is an example of Prokaryotes.

(iv) Bacteria have no nuclear membrane but possess chloroplasts

How do you say that a cell also has a life span and death like an organism? Give one example.

All organisms excrete. Does an individual cell also do it? Give one example.

Which one of the following cell organelles is correctly matched with its function?

(a) Ribosomes – Synthesis of proteins

(b) Mitochondria – Secretion of enzymes

(c) Plasma Membrane – Freely permeable

(d) Centrosome – Carries genes

All life starts as (a) An egg (b) A single cell (c) A gene (d) A chromosome

Which one of the following is found both in cells of a mango plant and a monkey? (a) chloroplasts (b) centrioles (c) cell wall (d) cell membrane

A plant cell can be identified from an animal cell by the: (a) Absence of centrosome (b) Presence of cell membrane (c) Presence of vacuoles (d) None of the above

Plant cell has a cell wall made of: (a) Protein (b) Fructose (c) Cellulose (d) Fatty acids

The cell organelle that helps in respiration of the cell is: (a) Mitochondria (b) Lysosome (c) Ribosome (d) Centrosome

Name the part of the cell concerned with the following?

(a) Liberation of energy

(b) Synthesis of proteins

(c) Transmission of heredity characters from parents to offspring

(d) Initiation of cell division

(e) Hydrolytic in function

(f) Entry of only certain substances into and out of the cell

State whether the following statements are true(T) or false(F):

(a) All animal cells contain a cell wall. T/F

(b) The cell wall is made of protein. T/F

(c) Centrosome occurs in animal cells T/F

(d) Plant cells contain large vacuoles. T/F

(e) Protoplasm is the part of the cell which surrounds the nucleus T/F

(f) Genes are located in chromosomes. T/F

(g) Anthocyanins are the pigments of flowers, which are dissolved in cell-sap. T/F

How many chromosome pairs are found in human cells?

What is the name of the chemical substance which constitutes the genes?

Match the items in column ‘A’ with those in column ‘B’ Column A Column B (a) Vacuoles (i) Intracellular digestion (b) Nucleolus (ii) respiratory enzymes (c) Lysosomes (iii) Covered by tonoplast (d) Anthocyanin (iv) Dissolved in the cytoplasm (e) Cristae (v) Forms RNA

Fill in the blanks:

(a) _______ consists of membranous sacs and secretes 40 types of digestive enzymes.

(b) _______ is surrounded by microtubules, located near the nucleus

(c) Very thin flexible, living membranes which is differently permeable, is called _______

(d) More than 1000 chromosomes are found in the nucleus of certain _____

(e) ______ are heredity units.

(f) _______ is a plastid which stores starch.

It is said that the protoplasm cannot be analysed chemically. Why?

What is the difference between an organ and an organelle?

Do you think the cells of an elephant would be larger than the cells of a rat? Explain briefly.

Differentiate between the following pairs of terms: (a) Protoplasm and cytoplasm (b) Nucleolus and nucleus (c) Centrosome and chromosome (d) Cell wall and cell membrane (e) Plant cell and animal cell (f) Prokaryotes and eukaryotes

Mention three features found only in plant cells and one found only in animal cells

Why are the cells generally of a small size?

What is the cell theory? Who propounded it and when?

Mention the three differences between a living cell and a brick in a wall.

Name the plastid and pigment likely to be found in the cells of:

(a) Petals of sunflower

(b) Ripe tomato

(c) Skin of green tomato

(d) Cells of potato.

State the major functions of the following:

(a) Plasma membrane

(b) Ribosome

(c) Lysosome

(d) Mitochondria

(e) Golgi apparatus

(f) Cytoplasm

(g) Asters of centrosome

(h) Chromosomes

(i) Glycogen granule

(j) Vacuoles

List any six features found both in plant and animal cells.

Given below are the sketches of two types of cells A and B

(a) Which one of these is a plant cell? Give reason in support of your answer.

(b) List the cell structures which are common to both the types

(c) Name the structures found only in plant cells and those found only in animal cells.