Question

5)give a brief account of discovery of the cell?
6)describe the proteins of plasma membrane ?
7)enumerate functions of plasma membrane ?
8)give an example of diffussion across plasma membrane?
9)set up an experiment to demonstrate osmosis.
11)write a note on endocytosis?
12)what would happen when eukaryotic cells are placed in hypotonic , hypertonic and isotonic solutions?
13)name the following:-
(a)smallest cell organelle
(b)largest cell organelle;
(c)ER studded with ribosomes
(d)functoinal segments with the DNA molecules

14)distinguish between the following:-
(b)ribosome and centrosome

16)what will happen in a cell if its nucleus is removed?give reasons in support of your answer.
17)explain why do spinach look green, papaya yellow and edible part of watermelon red?

18)write down two main functions of:-
(a)ER
(b)lysosome

19)name the following:-
(a)the cell organelle which synthesize protein.
(b)the type of plastids which store food.

20)"lysosomes are known as sucide bags".why?

21)define the following terms :
(a)cell inclusion
(b)cytosal
(c)protoplasm
(d)nucleoplasm

23)write short notes on :-
(a)mitochondria;
(b)plastids
24)write names of cell organelle.
25)what are three main functional regions ofbthe cell?

26)what is the location of the following in the cell:-
(a)chromatin
(b)chromosome
(c)tonoplast
(d)nucleolus

27)what are the genes?where are they located in the cell?
28)lysosomes are also called digestive bags.why?
29)which organelle is the " power plant " of eukaryotic cell .write in brief its functions.
30)what are centrioles?write about their function.
31)where do lipids and proteins constituting the plasma membrane get synthesised?
32)draw a well labelled diagram of typical prokaryotic cell?
33)what does the term plasmolysed mean when used to describe a cell?

Answer 1

5) Robert Hooke in the year 1665 observed soft bark from Oak tree under magnifying device he made. He observed that the cork resembled the structure of honeycomb consisting of many empty spaces like structure. He thought the work was made up by very small cavities. He called cavities as 'cell'. In Latin 'cell' means little room.
8) oxygen enters into the blood is example of diffusion
9) materials required:raw potato,bowls, pins, water, sharp knife
procedure: take the raw potato and boiled potato. peel off the skins. cut cube shaped cups from them. prepare few ml. of saturated sugar solution.pour sugar solution into potato cup to a level. mark the level of sugar solution by piercing the pin. keep the potato cup in Bowl. pour water in Bowl such. that the cup should not float or submerged. leave it for half an hour.
You can see that the the water is entered into potato cup due to process of osmosis.
11) The flexibility of plasma membrane enables the cell to engulf food and other substances from its external environment by endocytosis.
12) hypotonic solution:burst
hypertonic solution: shrink
isotonic solution: nothing happens
13) a) lysosomes
b)nucleus
c)rough endoplasmic reticulum
d) nucleus
14) ribosome synthesize protein whereas centrosome occurs in cell division process.