Uday 2025

PRACTICE SHEET

(BIOLOGY)
Chapter: Biomolecules
Multiple Choice Answer Type Questions these questions also has four alternative choices, any
one of which is the correct answer. You have to select
1. Haemoglobin has:
one of the codes (1), (2), (3) and (4) given below.
(1) primary structure.
(2) secondary structure. Assertion (A): Vitamin D cannot be stored in our
body.
(3) tertiary structure.
Reason (R): Vitamin D is fat soluble vitamin.
(4) quaternary structure.
(1) Both the assertion and reason are true, and the
reason is the correct explanation of the
2. In which of the following an anticodon occurs:
assertion.
(1) tRNA (2) mRNA
(2) Both the assertion and reason are true, and the
(3) rRNA (4) DNA reason is not the correct explanation of the
assertion.
3. Which of the following is a phospholipid? (3) Assertion is true, but reason is false.
(1) Sterol (2) Cholesterol (4) Assertion is false, but reason is true.
(3) Lecithin (4) Steroid
Very Short Answer Type Questions
4. Lipids are insoluble in water because lipid
molecules are: 10. Give any three differences between DNA and RNA.
(1) hydrophilic (2) neutral
11. What type of linkages hold together monomers of
(3) zwitter ions (4) hydrophobic
DNA?

5. The ratio between hydrogen and oxygen in a 12. Define enzymes.

carbohydrate is:
(1) 5 : 1 (2) 4 :3 13. What are amino acids?
(3) 3 : 1 (4) 2 :1
Short Answer Type Questions
6. A non-reducing sugar is: 14. Explain how the glycosidic bonds are made?
(1) glucose (2) sucrose 15. What is a disaccharide? Write briefly.
(3) fructose (4) maltose 16. Define phospholipid. Describe their arrangement in
the cell membrane.

7. Which one is basic amino acid? Long Answer Type Questions

(1) Proline (2) Arginine
(3) Methionine (4) Glycine 17. Define nucleic acids. Explain DNA and RNA with
their respective structures.
8. The most abundant biomolecule on earth:
(1) proteins (2) lipids Case Based Study Answer Type Questions
(3) nucleic acids (4) carbohydrates
18. Read the following and answer any four questions.
The sequence of bases in mRNA is read in serial
Assertion and Reason Answer Type Questions: order in groups of three at a time. Each triplet of
9. Direction: Each of these questions contains two nucleotides (having a specific sequence of bases) is
statements Assertion (A) and Reason (R). Each of known as codon. Each codon specifies one amino

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 acid. Many amino acids have more than one codon.
The amino acids are brought to mRNA by another II. Each triplet of nucleotides is called:
type of RNA called tRNA. Each amino acid has at (1) anticodon (2) codon
least one corresponding tRNA. At one end of the (3) mRNA (4) tRNA
tRNA is a trinucleotide base sequence on mRNA.
III. Each codon specifies:
I. Which of the following nitrogen bases is not present in (1) 1 amino acid (2) 2 amino acids
RNA? (3) 3 amino acids (4) None of these
(1) Thymine (2) Adenine
(3) Guanine (4) Cytosine
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 Answer Key

1. (4) 7. (2)
2. (1) 8. (4)
3. (3) 9. (4)
4. (4) 18. I-(1), II-(2), III-(1)
5. (4)
6. (2)

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 Hints & Solutions

Multiple Choice Answer Type Questions like enzymes, these are called ribozymes) which
increases the rate of biochemical reactions by
1. (4)
lowering down the activation energy but does not
Haemoglobin has a quaternary structure because it
affect the nature of final product.
consists of four polypeptide chains or subunits.
13. Amino acids are organic compounds containing an
2. (1)
amino group and an acidic group as substituents on
An anticodon is a three-nucleotide sequence that
the same carbon, i.e, the a-carbon. Hence, they are
would be found in tRNA.
called a-amino acids. a-amino acids are substituted
methane’s.
3. (3)
Lecithin is a phospholipid.
Short Answer Type Questions
4. (4)
14. A glycosidic bond is a type of covalent bond that
Lipids are hydrophobic means water-hating. They
joins a carbohydrate molecule to another group,
are water insoluble.
which may or may not be another carbohydrate. It
is formed by a condensation reaction between two
5. (4)
hydroxyl (-OH) groups, one from each molecule,
The ratio of hydrogen to oxygen in a carbohydrate
resulting in the loss of a water molecule. The
is 2 : 1.
glycosidic bond is catalysed by specific enzymes.
6. (2)
Sucrose is non-reducing sugar and glucose;
15. A disaccharide (also called a double sugar) is the
fructose and maltose are reducing sugar.
sugar formed when two monosaccharides (simple
7. (2) sugars) are joined by glycosidic linkage. Like
The basic amino acids are those that have a positive monosaccharides, disaccharides are soluble in
charge at physiological pH. They are Arginine, water. Three common examples are sucrose, lactose,
Lysine, and Histidine. and maltose.

8. (4) 16. Phospholipids are the main components of the cell

The most abundant biomolecule on earth is membrane. Each phospholipid molecule is
carbohydrates. Carbohydrates are produced by composed of two main parts:
photosynthetic bacteria, green algae, and green a. A hydrophilic (water-loving) head: This is made
plant cells. up of a phosphate group.
b. Two hydrophobic (water-hating) fatty acid tails:
Assertion and Reason Answer Type Questions: They are long chains mostly made up of hydrogen
9. (4) and carbon.
Assertion is false, but reason is true.
Long Answer Type Questions
Very Short Answer Type Questions 17. Nucleic acids are long-chain polymeric molecules
that are present in living cells and play a key role
10. Three differences between DNA and RNA are:
in transferring genetic information from one
a. DNA contains the sugar deoxyribose, while RNA
generation to the next. There are two types of
contains the sugar ribose.
nucleic acids: DNA (deoxyribonucleic acid) and
b. DNA is a double-stranded molecule, while RNA is
RNA (ribonucleic acid).
a single-stranded molecule.
DNA is a double helix formed by two
c. DNA uses the base thymine while RNA uses uracil.
polynucleotide chains that are twisted. It consists
of instructions that monitor the performance of all
11. The monomers of DNA are held together by phospho
cell functions. DNA is composed of pentose sugar,
diester linkages.
phosphoric acid, and four cyclic bases containing
12. Enzymes are biocatalysts made up of proteins
nitrogen: adenine (A), guanine (G), cytosine (C),
(except there are some nucleic acids that behave
and thymine (T). The arrangement of these bases in

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the molecules of DNA plays an important role in (U). The heterocyclic bases present in RNA are
the storage of information from one generation to adenine (A), guanine (G), cytosine (C), and uracil
the next. (U).
RNA, on the other hand, is generally a single-
stranded molecule that sometimes folds back. RNA
Case Based Study Answer Type Questions
plays a vital role in the synthesis of proteins that
mainly involves decoding and translation of 18. I-(1), II-(2), III-(1)
genetic code and transcription to produce proteins.
RNA is composed of phosphoric acid, a pentose
sugar, and four cyclic bases containing nitrogen:
adenine (A), guanine (G), cytosine (C), and uracil

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