Q. 1 Which cell organelle is associated with cell respiration.
A: Mitochondrian
Q.2 Define Nucleoid?
A: In some organism like bacteria - prokaryotes) the nuclear region is poorly defined due to absence of nuclear membrane. this is known as nucleoid.
Q. 3 Define
Plasmolysis?
A: Its the phenomenon, in which a living plant cell loses water through osomosis due to which content of cell shrinks away from the cell wall.
Q. 4 Give
function of Smooth Endoplasmic Reticulum in liver cells of Vertebrates?
A: It detoxifies many drugs and poison.
Q. 5 When
do the distance covered and magnitude of displacement of a moving body are equal?
A: When its moves in staight line in one direction.
Q. 6 Draw
a labeled diagram of a Prokaryotic cell?
A: Refer notes or book.
Q. 7 What
would happen if the plasma membrane ruptures or breaks down?
A: If it ruptures or breaks down the constant internal chemical
composition of the cell will be lost and it will not be able to perform its
basic functions. Such a cell with ruptured plasma membrane is dead.
Q. 8 How
is flexible nature of plasma membrane useful for Amoeba? Name this process?
A: its flexibility enables it to engulf food from the external environment by developing pseudopodia. Process is known as ENDOCYTOSYS.
Q. 9 Differentiate
between rough & smooth endoplasmic reticulum. How is endoplasmic reticulum
important for membrane biogenesis?
A; RER:
(a) Appears rough as ribosomes are embeded on its surface
(b) synthesize protein
(c) Enzymes of lysosomes are made by it.
SER:
(a) Appears smooth
(b) synthesize lipid and fat
(c) detoxifies poisons and drugs of liver cell in vertebrates
Membrane Bio-genesis:
Some of protein sythesized by RER and lipid and fat sythesized by SER is used up in building up the cell membrane. this proces is called membrane biogenesis.
Q. 10 Describe
the role played by the lysosomes in the cell. Why are these termed as suicide
bags?
A: (a) It keeps the cell clean by digesting any foreign particles that enters cell like bacteria.
During cellular metabolic disturbance, when the cell get damaged, lysosomes may burst and its enzyme digest its own cell. Hence it is called suicide bag.
Q. 11 A
motorcyclist drives from A to B with uniform speed of 60 km / hr. and returns
back with speed of 40 km/ hr. Find its average speed?
A; Let the distance be 'x' km. Hence total distance = 2x km.
time A to B = x/60 hr [ Time = Distance/ Speeed]
Time B to A = x/40 hr
total time = x/60 + x/40 = 5x/120 hr
Average speed = total distance / total time
[2x] / [5x/120] = 48 km/hr.
Q. 12 An
athlete completes one round of a circular track of diameter 200 m in 40 s. What
will be the distance covered and the displacement at the end of 2 minutes and
20 seconds?
A; Time : 2 min 20 sec = 140 sec.
Round in 40 sec. = 1
Round in 140 sec = [1/40]x 140 = 7/2 rounds.
Distance covered in one round = 2 x pi x r = 2 [22/7] [100] = 400/7 m
Distance in 7/2 rounds = [4400/7] x [7/2] = 2200 m
Displacement:
As after 3.5 rounds the athlete will be diametrically opposite hence dispacement will be = diameter of track = 200m
Q. 13 Draw
a labeled diagram of Mitochondria? Why it is called a strange Organelle?
A: Refer book/notes for figure.
Irt is strange becoze it has its own DNA and Ribososmes.
Q. 14 Name
three types of plastids? State one function of each?
A: Chloroplast : Synthsize food
Chromoplast: Imparts colors to flower and fruits and facilitate pollination by attracting insect.
, Leucoplast: Stores starch, oils and protein granules.
Q. 15 A
train starting from rest moves with a uniform acceleration of 0.2 m/s2 for 5
minutes. Calculate the speed acquired and the distance travelled in this time.
A: Caution : Change the time into seconds.
Given :
Initial Vel., u = 0 ( As train starts from rest)
a = 0.2 m/s2
t = 5 min. = 5 x 60 = 300 sec.
v = u + at = 0 + 0.2 x 300 = 60 m/s
Distance travelled
s = ut + a(t)(t) /2
= 0 + 0.2(300)(300) /2
= 9000 m
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