Revision Series | Science and Tech | Biology | 123

September 20, 2023

Which one of the following statement is correct about breathing.
A. It is a process which provides oxygen to the body.
B. In this process water is produced in the cell.
C. This process helps the body to get rid of carbon dioxide.
D. In this process food breaks down to release energy.

(A) A and C only
(B) C and D only
(C) A and B only
(D) None of the above

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ANSWER: A

Breathing – when we breathe, we take in oxygen-rich air from the environment and exhale carbon dioxide rich air.

This is a continual process that occurs throughout an organism’s life.
Inhalation is the process of taking in oxygen-rich air. Exhalation, on the other hand, refers to the process of exhaling carbon dioxide-rich air.
One inhalation and one exhale makeup one breath.

Respiration: Breathing is not similar to respiration.

Respiration is a chemical process whereas breathing is a physical process.
In respiration, processes at the cellular level are taking place.
Here, glucose (released by complete digestion of food) is broken down into water and carbon dioxide in the presence of oxygen.
ATP which is the energy currency is also released.

Which of the following events in the mouth cavity will be affected if salivary amylase is lacking in the saliva?

(A) Starch breaking down into sugars.
(B) Proteins breaking down into amino acids.
(C) Absorption of vitamins.
(D) Fats breaking down into fatty acids and glycerol.

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ANSWER: A

If the salivary glands are damaged or aren’t producing enough saliva, it can affect taste, make chewing and swallowing more difficult, and increase the risk for cavities, tooth loss, and infections in the mouth.

Posture and balance of the body is controlled by

(A) Pons
(B) Medulla oblongata
(C) Cerebellum
(D) Cerebrum

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Answer: C

Which of the following endocrine glands does not exist in pairs?

(A) Testes
(B) Adrenal
(C) Pituitary
(D) Ovary

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ANSWER: A

The embryo in humans gets nutrition from the mother’s blood with the help of a special tissue called

(A) Placenta
(B) Villi
(C) Uterus
(D) Womb

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Answer: A

The embryo receives nourishment from the mother via a tissue called the placenta.

Placenta connects the embryo to the uterine cavity of the mother via the umbilical cord.

The placenta contains villi on the side exposed to the embryo and the mother’s blood vessels surround the villi.

Which among the following sentence is not correct?

(A) Centrosome is absent in plant cells.
(B) Chromatin fibre is made up of DNA threads.
(C) Cell wall is absent in animal cell.
(D) Ribosomes destroy foreign substances.

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ANSWER: D

Lysosomes, which use enzymes to break down foreign matter and dead cells.

Nucleus contains thread like structures called ——-?

(A) Chromosomes
(B) Organelles
(C) Cytoplasm
(D) Vacuole

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ANSWER: A

Who is considered as the “ Father of Genetics ‘’ ?

(A) Gregor Mendel
(B) William Harvey
(C) Charles Darwin
(D) Werner Arber

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ANSWER: A

During photosynthesis, which by-product is released by plants ?

(A) Carbon dioxide
(B) Hydrogen
(C) Nitrogen
(D) Oxygen

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ANSWER: D

Our sensory endings possesses the ability to detect sounds that normally ranges between

(A) 20 – 20, 000 Hertz
(B) 10 – 15, 000 Hertz
(C) 8 – 25, 000 Hertz
(D) None of the above

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ANSWER: A

Which of the following statements is correct?

(A) Cell vacuoles do not store waste materials.
(B) Water transport in plants occurs across xylem.
(C) Breakdown of pyruvate in yeast in the presence of oxygen yields ethanol.
(D) None of the above.

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ANSWER: B

Vacuoles might store food or any variety of nutrients a cell might need to survive. They can even store waste products so the rest of the cell is protected from contamination.

Xylem transports water, minerals, and nutrients from the soil to all the plant parts. There are two types of “transport” tissues in plants- xylem and phloem.

Water and solutes are transported by the xylem from the roots to the leaves, and food is transported from the leaves to the rest of the plant by the phloem.

Fine organic or inorganic particles suspended in air is called_________

(A) Aerosol
(B) Particulate pollutant
(C) Gaseous pollutant
(D) None

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ANSWER: A

A tiny solid or liquid particle suspended in air or as a gas.
Aerosols can be natural, such as fog or gas from volcanic eruptions, or artificial, such as smoke from burning fossil fuels.

Cigarette smoking is responsible for the greatest exposure to ________

(A) Carbon monoxide
(B) Nitric oxide
(C) Carbondioxide
(D) Sulphurdioxide

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ANSWER: A

Tobacco smoke contains a poisonous gas called carbon monoxide.
You can’t smell it, see it or taste it.
Carbon monoxide stops the blood from carrying as much oxygen.
This means organs of the body don’t get the amount of oxygen they need, and the heart must work harder to supply the body with oxygen.

Which of the following is the name of the combination vaccine given to children to protect them against Tetanus, Whooping Cough, and Diphtheria?

(A) BCG Vaccine
(B) DPT Vaccine
(C) HIB Vaccine
(D) TAB Vaccine

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ANSWER: B

The DPT vaccine is a combination vaccine that protects children against tetanus, whooping cough, and diphtheria.
Diphtheria is represented by the letter D, Pertussis (whooping cough) by the letter P, and Tetanus by the letter T.
The DPT vaccine should be administered within 6 weeks of the baby’s birth.

The Air (Prevention and Control of Pollution) Act was enacted in the year

(A) 1981
(B) 1996
(C) 2000
(D) 1974

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ANSWER: A

29th March, 1981.An Act to provide for the prevention, control and abatement of air pollution, for the establishment, with a view to carrying out the aforesaid purposes, of Boards, for conferring on and assigning to such Boards powers and functions relating thereto and for matters connected therewith.