Light and Cells chapter worksheet ICSE Class 9

Cell (Q.1)  Why is the plasma  membrane called a selectively permeable membrane?
(Q.2)  Which cell organelle is known as the kitchen of the cell? Why?
(Q.3)   Mention any three differences between prokaryotic and eukaryotic cells?
(Q.4)   Enlist any three differences between plant and animal cell?

Q.5)  Write any four differences between the plasma membrane and cell wall.
(Q.6)  Why are Mitochondria known as power house of the cell?
(Q.7)  What are the types of plastids? Write their names and fuctions.
(Q.8)  Differentiate between prokaryotic and eukaryotic cell.
(Q.9)  State true or false and rewrite the false statements correctly. i. Ribosomes are the power house of the cell. ii. Chromoplast is the pigmented plastid. iii. Animal cell have cell wall. iv. Centrosome is absent in animal cell. v. The reserve food material of animal cell is starch.
(Q.10)  Give one word answer for each of the following. i. Longest cells of the body ii. Reserve food of plant cell iii. Suicidal Bags of the cell iv. Non-pigmented plastid v. Power house of the cell
(Q.11)   Name the plastid that impart colour to flowers and fruit.

(Q.12)   What are those organisms called, which are made up of millions and billions of cells?
(Q.14)   What are those organisms called, which are made up of only one cell.

(Q.15)   Name the plant cells that control opening and closing of stomata?

(Q.16)   Name the basic unit of life.

LIGHT

(Q.1)  Name the mirror which always produces an erect and virtual image.

(Q.2)  State four uses of a plane mirror.

(Q.3)  Draw a neat and clean two ray diagram for the formation of images in two plane mirrors, when mirrors are (i) at right angles to each other (ii) when mirrors are facing each other.

(Q.4)  Reflection of light takes place from a
(A) plane mirror.
(B) concave lens.
(C) convex lens.
(D) bifocal lens.

(Q.5)  State the laws of reflection.

(Q.6)  Why infinite images are not seen when two plane mirrors are kept facing each other? Give two reasons.

(Q.7)  . Calculate the number of images formed in two plane mirrors, when they are held at the angle of

(i) 60⁰   (ii) 40^o.