1)
The kidneys in human beings are a part of the system for
The kidneys in human beings are a part of the system for
(a)
nutrition.
nutrition.
(b)
respiration.
respiration.
(c)
excretion.
excretion.
(d)
transportation.
transportation.
ANSWER:-In human beings, the kidneys are a part of the system for
excretion.
excretion.
2)
The xylem in plants are responsible for
The xylem in plants are responsible for
(a)
transport of water.
transport of water.
(b)
transport of food.
transport of food.
(c)
transport of amino acids.
transport of amino acids.
(d)
transport of oxygen.
transport of oxygen.
ANSWER:-In
a plant, the xylem is responsible for transport of water.
a plant, the xylem is responsible for transport of water.
3)
The autotrophic mode of nutrition requires
The autotrophic mode of nutrition requires
(a)
carbon dioxide and water.
carbon dioxide and water.
(b)
chlorophyll.
chlorophyll.
(c)
sunlight.
sunlight.
(d)
all of the above.
all of the above.
ANSWER:-The
autotrophic mode of nutrition requires carbon dioxide, water, chlorophyll and
sunlight.
autotrophic mode of nutrition requires carbon dioxide, water, chlorophyll and
sunlight.
4
)The breakdown of pyruvate to give carbon dioxide, water and energy takes place
in
)The breakdown of pyruvate to give carbon dioxide, water and energy takes place
in
(a)
cytoplasm.
cytoplasm.
(b)
mitochondria.
mitochondria.
(c)
chloroplast.
chloroplast.
(d)
nucleus.
nucleus.
ANSWER:-The
breakdown of pyruvate to give carbon dioxide, water and energy takes place in
breakdown of pyruvate to give carbon dioxide, water and energy takes place in
Mitochondria.
5)
How are fats digested in our bodies? Where does this process take place?
How are fats digested in our bodies? Where does this process take place?
ANSWER:-Fats
are present in the form of large globules in the small intestine. The small intestine gets the
secretions in the form of bile juice and pancreatic juice respectively from the
liver and the pancreas. The bile salts (from the liver) break
down the large fat globules into smaller globules so that the pancreatic
enzymes can easily act on them.
are present in the form of large globules in the small intestine. The small intestine gets the
secretions in the form of bile juice and pancreatic juice respectively from the
liver and the pancreas. The bile salts (from the liver) break
down the large fat globules into smaller globules so that the pancreatic
enzymes can easily act on them.
The
process takes place in the small intestine.
process takes place in the small intestine.
6)
What is the role of saliva in the digestion of food?
What is the role of saliva in the digestion of food?
ANSWER:
– It moistens the food for easy swallowing. It contains a digestive enzyme
called salivary amylase, which breaks down starch into sugar.
– It moistens the food for easy swallowing. It contains a digestive enzyme
called salivary amylase, which breaks down starch into sugar.
7)
What are the necessary conditions for autotrophic nutrition and what are its
by-products?
What are the necessary conditions for autotrophic nutrition and what are its
by-products?
ANSWER:-Autotrophic nutrition takes place through the process
of photosynthesis. Carbon dioxide, water, chlorophyll pigment, and sunlight are
the necessary
conditions required for autotrophic nutrition. Carbohydrates and O2 are the
by-products of photosynthesis.
of photosynthesis. Carbon dioxide, water, chlorophyll pigment, and sunlight are
the necessary
conditions required for autotrophic nutrition. Carbohydrates and O2 are the
by-products of photosynthesis.
8.)
What are the differences between aerobic and anaerobic respiration? Name some organisms that use
the anaerobic mode of respiration.
What are the differences between aerobic and anaerobic respiration? Name some organisms that use
the anaerobic mode of respiration.
ANSWER: – Parasitic worms, animal muscles use anaerobic mode of
respiration.
respiration.
|
Aerobic respiration
|
Anaerobic
respiration |
|
It occurs in the presence of O2.
|
It occurs in the absence of O2.
|
|
It involves the exchange of gases.
|
Exchange of gases is does not happen.
|
|
It occurs in cytoplasm and
mitochondria. |
It occurs only in cytoplasm.
|
|
It always releases CO2 and
H2O. |
End products vary
|
9)
How are the alveoli designed to maximize the exchange of gases?
How are the alveoli designed to maximize the exchange of gases?
ANSWER:-The
walls of the alveoli
consist of extensive network of blood vessels. Each lung contains 300−350 million alveoli, making it a total of approximately 700
million in both the lungs. The alveolar surface when spread out covers about 80 m2 area. This large
surface area makes the gaseous exchange more efficient.
walls of the alveoli
consist of extensive network of blood vessels. Each lung contains 300−350 million alveoli, making it a total of approximately 700
million in both the lungs. The alveolar surface when spread out covers about 80 m2 area. This large
surface area makes the gaseous exchange more efficient.
10)
What would be the consequences of a deficiency of haemoglobin in our bodies?
What would be the consequences of a deficiency of haemoglobin in our bodies?
ANSWER:-Deficiency
of haemoglobin in blood can affect the oxygen supplying
capacity of blood. This can lead to deficiency of oxygen in the body cells. It
can also
lead to a disease called anemia.
of haemoglobin in blood can affect the oxygen supplying
capacity of blood. This can lead to deficiency of oxygen in the body cells. It
can also
lead to a disease called anemia.
11)
Describe double circulation in human beings. Why is it necessary?
Describe double circulation in human beings. Why is it necessary?
ANSWER:-Human
heart is divided into four chambers − the
right atrium, the right ventricle, the left atrium, and the left ventricle.
heart is divided into four chambers − the
right atrium, the right ventricle, the left atrium, and the left ventricle.
Flow
of blood in the heart:
of blood in the heart:
The
heart has superior and inferior vena cava, which carries de-oxygenated blood
from the
upper and lower regions of the body respectively and supplies this
de-oxygenated blood
to the right atrium of the heart.
heart has superior and inferior vena cava, which carries de-oxygenated blood
from the
upper and lower regions of the body respectively and supplies this
de-oxygenated blood
to the right atrium of the heart.
The
right atrium then contracts and passes the de-oxygenated blood to the right
ventricle, through an auriculo-ventricular aperture.
right atrium then contracts and passes the de-oxygenated blood to the right
ventricle, through an auriculo-ventricular aperture.
Then
the right ventricle contracts and passes the de-oxygenated blood into the two
pulmonary arteries, which pumps it to the lungs where the blood becomes oxygenated.
the right ventricle contracts and passes the de-oxygenated blood into the two
pulmonary arteries, which pumps it to the lungs where the blood becomes oxygenated.
From
the lungs, the pulmonary veins transport the oxygenated blood to the left
atrium of the heart.
the lungs, the pulmonary veins transport the oxygenated blood to the left
atrium of the heart.
Then
the left atrium contracts and through the auriculo-ventricular aperture, the
oxygenated blood enters the left ventricle.
the left atrium contracts and through the auriculo-ventricular aperture, the
oxygenated blood enters the left ventricle.
The
blood passes to aorta from the left ventricle. The aorta gives rise to many
arteries that distribute the oxygenated blood to all the regions of the body.
blood passes to aorta from the left ventricle. The aorta gives rise to many
arteries that distribute the oxygenated blood to all the regions of the body.
12)
What are the differences between the transport of materials in xylem and
phloem?
What are the differences between the transport of materials in xylem and
phloem?
ANSWER:-
|
Transport
of materials in xylem |
Transport
of materials in phloem |
|
Xylem tissue helps in the transport of
water and minerals. |
Phloem tissue helps in the transport
of food. |
|
Water is transported upwards from
roots to aerial parts of plants |
Food is transported in both upward and
downward directions. |
|
Transport in xylem requires physical
forces such as transpiration pull. |
Transport of food in phloem requires
energy in the form of ATP. |
13)
Compare the functioning of alveoli in the lungs and nephrons in the kidneys
with respect to their structure and functioning.
Compare the functioning of alveoli in the lungs and nephrons in the kidneys
with respect to their structure and functioning.
ANSWER:-
|
Alveoli
|
Nephrons
|
|
Structure
|
Structure
|
|
(i) Alveoli are tiny
balloon-like structurespresent inside the lungs. |
(i) Nephrons are tubular structures present
inside the kidneys. |
|
(ii) The walls of the alveoli are one
cell thick and it contains an extensive network of blood capillaries. |
(ii) Nephrons are made of
glomerulus, bowman’s capsule, and a long renal tube. |
|
Function
|
Function
|
|
(i) The exchange of O2 and
CO2 takes place between the blood of the capillaries that surround the alveoli and the gases present in the alveoli. |
(i) The blood enters the kidneys through the
renal artery. The blood is entered here and the nitrogenous waste in the form of urine is collected by collecting duct. |
|
(ii) Alveoli are the
site of gaseous exchange. |
(ii) Nephrons are the
basic filtration unit. |