Extra 30 short questions and answers from Chapter:5 Life Processes for Class 10 CBSE Science:
Short Answer Questions
What are the different types of nutrition? Explain with examples.
Ans:
There are two types of nutrition:
Autotrophic Nutrition
– Organisms prepare their own food (e.g., plants, algae).
Heterotrophic Nutrition
– Organisms depend on others for food (e.g., animals, fungi).
What is the role of chlorophyll in photosynthesis?
Ans:
Chlorophyll is a green pigment in chloroplasts that absorbs sunlight and converts it into chemical energy to synthesize glucose.
Write the balanced chemical equation for photosynthesis.
Ans:
6CO2+6H2O→sunlight, chlorophyllC6H12O6+6O26CO_2 + 6H_2O \righteous{\text{sunlight, chlorophyll}} C_6H_{12}O_6 + 6O_26CO2+6H2Sunlight, chlorophyllC6H12O6+6O2
What is the function of stomata in plants?
Ans:
Stomata are tiny pores on leaves that help in:
Gas exchange
(CO₂ intake, O₂ release)
Transpiration
(water loss for cooling)
What is emulsification of fats? Name the organ that performs it.
Ans:
Emulsification is the breakdown of large fat globules into smaller droplets by
bile juice
secreted by the
liver
to aid digestion.
What is peristalsis? Where does it occur?
Ans:
Peristalsis is the rhythmic contraction of muscles in the alimentary canal (e.g.,
oesophagus
, intestines) to push food forward.
Why is the small intestine long in herbivores but short in carnivores?
Ans:
Herbivores eat plant material rich in cellulose, requiring a longer intestine for digestion, while carnivores digest meat faster, needing a shorter intestine.
Why do we feel cramps in our muscles after excessive exercise?
Ans:
Due to lack of oxygen, muscles undergo
anaerobic respiration
, producing
lactic acid
, which causes cramps.
Differentiate between aerobic and anaerobic respiration.
Ans:
Aerobic Respiration
– Uses oxygen, produces more energy (ATP), occurs in mitochondria.
Anaerobic Respiration
– No oxygen used, less energy, occurs in some microorganisms and muscle cells.
Why do we breathe faster during vigorous exercise?
Ans:
More energy is required, so the body increases oxygen intake and CO₂ removal, making breathing faster.
How is respiration different from breathing?
Ans:
Breathing
– Physical process of inhaling and exhaling air.
Respiration
– Biochemical process of breaking down glucose to release energy (ATP).
What is the role of alveoli in respiration?
Ans:
Alveoli are air sacs in lungs where
gas exchange
occurs – oxygen diffuses into blood, and carbon dioxide diffuses out.
How is oxygen transported in human blood?
Ans:
Oxygen binds with
haemoglobin
in RBCs and is transported to tissues.
What is the significance of ATP in respiration?
Ans:
ATP (Adenosine Triphosphate) is the energy currency of cells used for all biological activities.
What is double circulation in humans?
Ans:
In humans, blood passes through the heart
twice
in one complete cycle:
Pulmonary Circulation
– Between heart and lungs.
Systemic Circulation
– Between heart and body.
Why is the human heart
called
a four-chambered heart?
Ans:
The heart has
four chambers
:
Two atria
(upper chambers)
Two ventricles
(lower chambers)
Why do arteries have thick walls?
Ans:
Arteries carry oxygenated blood under
high pressure
, so their walls are thick and elastic to withstand it.
Differentiate between arteries and veins.
Ans:
Arteries
– Carry oxygenated blood (except pulmonary artery), thick-walled, high pressure.
Veins
– Carry deoxygenated blood (except pulmonary vein), thin-walled, low pressure.
What are platelets and what is their function?
Ans:
Platelets are blood cells responsible for
blood clotting
to prevent excessive bleeding.
How does the lymphatic system help in circulation?
Ans:
The
lymphatic system
transports excess fluid from tissues back to the blood and fights infections using WBCs.
What is the main excretory product in humans? Name the organ responsible.
Ans:
The main excretory product is
urea
, which is removed by the
kidneys
.
What is dialysis? When is it needed?
Ans:
Dialysis is an artificial process that filters blood when kidneys fail to function properly.
What is osmoregulation? Which organ performs it?
Ans:
Osmoregulation is maintaining
water and ion balance
in the body, performed by the
kidneys
.
Name two excretory products in plants.
Ans:
Oxygen, resins, latex, and gums.
What is the role of the nephron in excretion?
Ans:
The
nephron
is the structural unit of the kidney that filters blood and forms urine.
How does sweating help in excretion and temperature control?
Ans:
Sweating removes
salt and water
from the body and cools it down through
evaporation
.
Why is digestion necessary for the body?
Ans:
Digestion breaks down complex food into simpler substances (glucose, amino acids) that the body can absorb and use for energy.
Why does blood appear red?
Ans:
Due to the presence of
haemoglobin
, which binds with oxygen.
What is transpiration? List its two functions.
Ans:
Transpiration is the loss of water from leaves. Functions:
Cooling the plant
Absorption and transport of water
How do guard cells control the opening and closing of stomata?
Ans:
Guard cells swell with water (stomata open) and shrink when dehydrated (stomata close), regulating gas exchange.
