EVENTS
CONVENT HIGH SCHOOL
05/08/2021 CLASS-10 SESSION2021-22(SLOT-1)
SCIENCE
Chapter-6
life process
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Tick the correct option :-
Question 1The kidneys
in human beings are a part of the system for
(i) nutrition
(ii) respiration
(iii) excretion
(iv) transportation
Answer:
(iii) Excretion
Question 2The xylem in
plants are responsible for
(i) transport of water
(ii) transport of food
(iii) transport of
amino acids
(iv) transport of
oxygen
Answer:
(i) Transport of water
Question 3The
autotrophic mode of nutrition requires
(i) carbon dioxide and
water
(ii) chlorophyll
(iii) sunlight
(iv) all of the above
Answer:
(iv) All of the above
Question 4The
breakdown of pyruvate to give carbon dioxide, water and energy takes place in
(i) cytoplasm
(ii) mitochondria
(iii) chloroplast
(iv) nucleus
Answer:
(ii) Mitochondria
Question 5How are fats
digested in our bodies ? Where does this process take place ?
Answer:Digestion of
fats takes place in the small intestine.
Bile juice secreted by
the liver poured in the intestine along with pancreatic juice. The bile salts
present in the bile juice emulsify fhe large globules of fats. Therefore, by
enulsification large globules break down into fine globules to provide larger
surface area to act upon by the enzymes.
Lipase enzyme present
in the pancreatic juice causes break down of emulsified fats. Glands present in
the wall of small intestine secrete intestinal juice which contains lipase
enzyme that converts fats into fatty acids and glycerol.
Question 6What is the
role of saliva in the digestion of food ?
Answer:Saliva contains
salivary amylase enzyme that breaks down starch into sugars like maltose.
Saliva keeps the mouth
cavity clean and moistens the food that help in chewing and breaking down the
big pieces of food into smaller ones.
Question 7What are the
necessary conditions (or autotrophic nutrition and what are its by-products ?
Answer:Necessary
conditions for autotrophic nutrition :
(i) Presence of
chlorophyll in the living cells.
(if) Provision of
supply of water to green plants or cells of the plant.
(iii) Sufficient
sunlight.
(iv) Sufficient supply
of carbon dioxide.
By-product of auto
tropic nutrition is oxygen.
Question 8What are the
differences between aerobic and anaerobic respiration ? Name some organisms
that use the anaerobic mode of respiration.
Answer:Aerobic respiration Anaerobic respiration
1. It takes place in
the presence of oxygen. 1. It takes place in the absence of
oxygen.
2. Complete breakdown
of food occurs in aerobic respiration. 2.
Partial breakdown of food occurs in anaerobic respiration.
3. The end products in
aerobic respiration are carbon dioxide and water. 3. The end products in anaerobic respiration may be ethanol
and carbon dioxide (as in yeast plants) or lactic acid (as in animal muscles).
4. Aerobic respiration
produces a considerable amount of energy. 4.
Much less energy is produced in anaerobic respiration.
Some organisms which
use anaerobic respiration are yeast, bacteria etc.
Question 9How are the
alveoli designed to maximise the exchange of gases ?
Answer:(i) The alveoli
are thin walled and richly supplied with a network of blood vessels to
facilitate exchange of gases between blood and the air filled in alveoli.
(ii) Alveoli have
balloon-like structure. Hence, provide maximum surface for exchange of gases.
Question 10What would
be the consequences of a deficiency of haemoglobin in our bodies?
Answer:Due to the
deficiency of haemoglobin in blood, its oxygen carrying capacity decreases. As
a result the production of energy by oxidation will become slower. Therefore,
one would fall sick and would feel fatigue most of the time.
Question 11Describe
double circulation in human beings. Why is it necessary ?
Answer:In our heart
blood enters twice and also pumped out twice from the heart. The deoxygenated
blood from the body is brought to the right atrium through vena cava from where
it is sent to right ventricle. From right ventricle, the blood is pumped to the
lungs for oxygenation through pulmonary artery. The oxygenated blood from lungs
again enters the left atrium of the heart through pulmonary veins. From left
atrium it is send to left ventricle, from where this oxygenated blood is pumped
to different parts of body through the arteries. In this way the blood flows
through the heart twice, that’s why it is called ‘double circulation’.
Necessity of double
circulation: The right side and the left side of the human heart are useful to
keep deoxygenated and oxygenated blood from mixing. This type of separation of
oxygenated and deoxygenated blood ensures a highly efficient supply of oxygen to
the body. This is useful in case of humans who constantly need energy to
maintain their body temperature.
Question 12What are
the differences between the transport of materials in xylem and phloem ?
Answer:
Xylem Phloem
1. Xylem conducts water and dissolved minerals
from roots to leaves and other parts. 1.
Phloem conducts prepared food material from leaves to other parts of plant in
dissolved form.
2. In xylem, the
transport of material takes place through vessels and tracheids which are dead
tissues. 2. In phloem,
transport of material takes place through sieve tubes with the help of
companion cells, which are living cells.
3. In xylem upward
movement of water and dissolved minerals is mainly achieved by transpiration
pull. It is caused due to suction created by evaporation of water molecules
from the cells of a leaf. 3. In
translocation, material is transferred into phloem tissue using energy from
ATP. This increases the osmotic pressure that moves the material in the phloem
to tissues which have less pressure
Question 13Compare the
functioning of alveoli in the lungs and nephrons in the kidneys with respect to
their structure and functioning.
Answer:
Alveoli Nephron
1. Alveoli are
functional unit of lungs. 1.
Nephrons are functional unit of kidney.
2. A mature lung has
about 30 crore alveoli. 2. A
kidney has about 10 lakh nephrons.
3. Alveoli provide a
wide surface for gaseous exchange. 3.
The surface area of a nephron is not much more.
4. The exchange of O2
and CO2 takes place through the network of capillaries in alveoli. 4. The Bowman’s capsule in nephron
regulates the concentration of water and salts.
