Page 1
CBSE XI | BIOLOGY
Sample Paper – 1 Solution
CBSE
Class XI Biology
Sample Paper – 1 Solution
SECTION A
1. Male – Antheridia; Female – Oogonia
OR
Bryophytes can live on land but depend on water for sexual reproduction. Hence,
bryophytes are called amphibians of the plant kingdom.
2. When the leaf base expands into a sheath covering the stem partially or wholly, it is
called a sheathing leaf base.
3. The nucleolus is the site of active ribosomal RNA synthesis.
4. They are specific for a substance.
OR
Catalase catalyses the breakdown of hydrogen peroxide into water and oxygen.
5. Bowman’s capsule
SECTION B
6. Cnidarians exhibit two body forms—polyp and medusa.
Polyp Medusa
i. The polyp form is sessile and cylindrical.
ii. Example: Hydra
i. The medusa form is umbrella-shaped and
free-swimming.
ii. Example: Aurelia
7. The amount of imbibition depends on
i. The water potential gradient between the adsorbent and the liquid/water imbibed.
ii. The affinity between the absorbent and the imbibed liquid.
OR
Sinks for mineral elements or ions in plants:
? Apical and lateral meristems
? Young leaves
? Storage organs
? Developing flowers, fruits and seeds
Page 2
CBSE XI | BIOLOGY
Sample Paper – 1 Solution
CBSE
Class XI Biology
Sample Paper – 1 Solution
SECTION A
1. Male – Antheridia; Female – Oogonia
OR
Bryophytes can live on land but depend on water for sexual reproduction. Hence,
bryophytes are called amphibians of the plant kingdom.
2. When the leaf base expands into a sheath covering the stem partially or wholly, it is
called a sheathing leaf base.
3. The nucleolus is the site of active ribosomal RNA synthesis.
4. They are specific for a substance.
OR
Catalase catalyses the breakdown of hydrogen peroxide into water and oxygen.
5. Bowman’s capsule
SECTION B
6. Cnidarians exhibit two body forms—polyp and medusa.
Polyp Medusa
i. The polyp form is sessile and cylindrical.
ii. Example: Hydra
i. The medusa form is umbrella-shaped and
free-swimming.
ii. Example: Aurelia
7. The amount of imbibition depends on
i. The water potential gradient between the adsorbent and the liquid/water imbibed.
ii. The affinity between the absorbent and the imbibed liquid.
OR
Sinks for mineral elements or ions in plants:
? Apical and lateral meristems
? Young leaves
? Storage organs
? Developing flowers, fruits and seeds
CBSE XI | BIOLOGY
Sample Paper – 1 Solution
8. They absorb the different wavelengths of light and pass on the energy to the reaction
centre.
9.
(a) Watson and Crick proposed the double helical model of DNA.
(b) The two strands are antiparallel because they run in opposite directions, one in the
5'–3' direction and the other in the 3'–5' direction.
OR
i. Freely in the cytoplasm
ii. Attached to ER in the cytoplasm
iii. Inside mitochondria
iv. Inside plastids
10. Differences between red algae and brown algae:
Red algae Brown algae
1. They have a characteristic pigment
– phycoerythrin.
1. They have a characteristic pigment
– fucoxanthin.
2. They do not have any flagellated or
motile structures.
2. They have flagellated gametes and
zoospores.
3. Reserve food material is in the form
of floridean starch.
3. Reserve food material is in the
form of laminarin and mannitol.
4. Agar and carrageen are the
phycocolloids.
4. Algin is the phycocolloid.
11.
i. stores starch in potato - Parenchyma
ii. forms the shell in nuts - Sclerenchyma
12. Amino acids in a protein are held together by a peptide bond which is formed when the
carboxyl (-COOH) group of one amino acid reacts with the amino (-NH2) group of the
next amino acid with the elimination of a water molecule.
SECTION C
13. Double fertilisation is unique to angiosperms. In this phenomenon, two male gametes
are discharged by a pollen tube into the embryo sac of an ovule. One male gamete fuses
with the female gamete to form a zygote. This fusion is called syngamy. A second male
gamete fuses with the secondary nucleus to form the primary endosperm nucleus. This
is called triple fusion.
Page 3
CBSE XI | BIOLOGY
Sample Paper – 1 Solution
CBSE
Class XI Biology
Sample Paper – 1 Solution
SECTION A
1. Male – Antheridia; Female – Oogonia
OR
Bryophytes can live on land but depend on water for sexual reproduction. Hence,
bryophytes are called amphibians of the plant kingdom.
2. When the leaf base expands into a sheath covering the stem partially or wholly, it is
called a sheathing leaf base.
3. The nucleolus is the site of active ribosomal RNA synthesis.
4. They are specific for a substance.
OR
Catalase catalyses the breakdown of hydrogen peroxide into water and oxygen.
5. Bowman’s capsule
SECTION B
6. Cnidarians exhibit two body forms—polyp and medusa.
Polyp Medusa
i. The polyp form is sessile and cylindrical.
ii. Example: Hydra
i. The medusa form is umbrella-shaped and
free-swimming.
ii. Example: Aurelia
7. The amount of imbibition depends on
i. The water potential gradient between the adsorbent and the liquid/water imbibed.
ii. The affinity between the absorbent and the imbibed liquid.
OR
Sinks for mineral elements or ions in plants:
? Apical and lateral meristems
? Young leaves
? Storage organs
? Developing flowers, fruits and seeds
CBSE XI | BIOLOGY
Sample Paper – 1 Solution
8. They absorb the different wavelengths of light and pass on the energy to the reaction
centre.
9.
(a) Watson and Crick proposed the double helical model of DNA.
(b) The two strands are antiparallel because they run in opposite directions, one in the
5'–3' direction and the other in the 3'–5' direction.
OR
i. Freely in the cytoplasm
ii. Attached to ER in the cytoplasm
iii. Inside mitochondria
iv. Inside plastids
10. Differences between red algae and brown algae:
Red algae Brown algae
1. They have a characteristic pigment
– phycoerythrin.
1. They have a characteristic pigment
– fucoxanthin.
2. They do not have any flagellated or
motile structures.
2. They have flagellated gametes and
zoospores.
3. Reserve food material is in the form
of floridean starch.
3. Reserve food material is in the
form of laminarin and mannitol.
4. Agar and carrageen are the
phycocolloids.
4. Algin is the phycocolloid.
11.
i. stores starch in potato - Parenchyma
ii. forms the shell in nuts - Sclerenchyma
12. Amino acids in a protein are held together by a peptide bond which is formed when the
carboxyl (-COOH) group of one amino acid reacts with the amino (-NH2) group of the
next amino acid with the elimination of a water molecule.
SECTION C
13. Double fertilisation is unique to angiosperms. In this phenomenon, two male gametes
are discharged by a pollen tube into the embryo sac of an ovule. One male gamete fuses
with the female gamete to form a zygote. This fusion is called syngamy. A second male
gamete fuses with the secondary nucleus to form the primary endosperm nucleus. This
is called triple fusion.
CBSE XI | BIOLOGY
Sample Paper – 1 Solution
14. The underground parts of a plant are not always roots because
i. Plants such as potato, ginger, onion and Colocasia have underground stems.
ii. Underground stems show nodes and internodes.
iii. They also have terminal buds and axillary buds.
OR
Characteristics of the cells in the region of the meristem in roots:
? Small in size
? Thin-walled
? Dense protoplasm
? Divide repeatedly
15.
i. The pericycle is positioned just inner to the endodermis.
ii. The protoxylem elements are towards the external surface, while the metaxylem
elements are found towards the core.
iii. Such an arrangement of the xylem is called exarch.
16. Alimentary canal of cockroach:
17. The cytoskeleton is an elaborate network of filamentous proteinaceous structures
present in the cytoplasm.
Functions of the cytoskeleton:
i. Cytoskeletal structures maintain the shape of the cell and its extensions.
ii. It regulates the orientation and distribution of cell organelles.
iii. It helps in the intracellular transport and movement of cells.
OR
Page 4
CBSE XI | BIOLOGY
Sample Paper – 1 Solution
CBSE
Class XI Biology
Sample Paper – 1 Solution
SECTION A
1. Male – Antheridia; Female – Oogonia
OR
Bryophytes can live on land but depend on water for sexual reproduction. Hence,
bryophytes are called amphibians of the plant kingdom.
2. When the leaf base expands into a sheath covering the stem partially or wholly, it is
called a sheathing leaf base.
3. The nucleolus is the site of active ribosomal RNA synthesis.
4. They are specific for a substance.
OR
Catalase catalyses the breakdown of hydrogen peroxide into water and oxygen.
5. Bowman’s capsule
SECTION B
6. Cnidarians exhibit two body forms—polyp and medusa.
Polyp Medusa
i. The polyp form is sessile and cylindrical.
ii. Example: Hydra
i. The medusa form is umbrella-shaped and
free-swimming.
ii. Example: Aurelia
7. The amount of imbibition depends on
i. The water potential gradient between the adsorbent and the liquid/water imbibed.
ii. The affinity between the absorbent and the imbibed liquid.
OR
Sinks for mineral elements or ions in plants:
? Apical and lateral meristems
? Young leaves
? Storage organs
? Developing flowers, fruits and seeds
CBSE XI | BIOLOGY
Sample Paper – 1 Solution
8. They absorb the different wavelengths of light and pass on the energy to the reaction
centre.
9.
(a) Watson and Crick proposed the double helical model of DNA.
(b) The two strands are antiparallel because they run in opposite directions, one in the
5'–3' direction and the other in the 3'–5' direction.
OR
i. Freely in the cytoplasm
ii. Attached to ER in the cytoplasm
iii. Inside mitochondria
iv. Inside plastids
10. Differences between red algae and brown algae:
Red algae Brown algae
1. They have a characteristic pigment
– phycoerythrin.
1. They have a characteristic pigment
– fucoxanthin.
2. They do not have any flagellated or
motile structures.
2. They have flagellated gametes and
zoospores.
3. Reserve food material is in the form
of floridean starch.
3. Reserve food material is in the
form of laminarin and mannitol.
4. Agar and carrageen are the
phycocolloids.
4. Algin is the phycocolloid.
11.
i. stores starch in potato - Parenchyma
ii. forms the shell in nuts - Sclerenchyma
12. Amino acids in a protein are held together by a peptide bond which is formed when the
carboxyl (-COOH) group of one amino acid reacts with the amino (-NH2) group of the
next amino acid with the elimination of a water molecule.
SECTION C
13. Double fertilisation is unique to angiosperms. In this phenomenon, two male gametes
are discharged by a pollen tube into the embryo sac of an ovule. One male gamete fuses
with the female gamete to form a zygote. This fusion is called syngamy. A second male
gamete fuses with the secondary nucleus to form the primary endosperm nucleus. This
is called triple fusion.
CBSE XI | BIOLOGY
Sample Paper – 1 Solution
14. The underground parts of a plant are not always roots because
i. Plants such as potato, ginger, onion and Colocasia have underground stems.
ii. Underground stems show nodes and internodes.
iii. They also have terminal buds and axillary buds.
OR
Characteristics of the cells in the region of the meristem in roots:
? Small in size
? Thin-walled
? Dense protoplasm
? Divide repeatedly
15.
i. The pericycle is positioned just inner to the endodermis.
ii. The protoxylem elements are towards the external surface, while the metaxylem
elements are found towards the core.
iii. Such an arrangement of the xylem is called exarch.
16. Alimentary canal of cockroach:
17. The cytoskeleton is an elaborate network of filamentous proteinaceous structures
present in the cytoplasm.
Functions of the cytoskeleton:
i. Cytoskeletal structures maintain the shape of the cell and its extensions.
ii. It regulates the orientation and distribution of cell organelles.
iii. It helps in the intracellular transport and movement of cells.
OR
CBSE XI | BIOLOGY
Sample Paper – 1 Solution
Differences between primary cell wall and secondary cell wall:
Primary cell wall Secondary cell wall
? It is the cell wall of young cells. ? It is the cell wall formed inner to the
primary wall in older cells.
? It is traversed by plasmodesmata. ? It is traversed by pits.
? It is made of mainly cellulose. ? It is made of lignin, pectin and
suberin.
18.
i. The four microspores formed by meiosis in a microspore mother cell are equal.
ii. The four spermatids formed from a spermatocyte are equal.
iii. When a primary oocyte undergoes meiosis I, a large secondary oocyte and a small
cell, the polar body, are formed.
19.
i. Monoglyceride is a lipid with one molecule of glycerol and one molecule of fatty
acid.
ii. Diglyceride is a lipid with one molecule of glycerol and two molecules of fatty acids.
iii. Triglyceride is a lipid with one molecule of glycerol and three molecules of fatty
acids.
20. The important events in aerobic respiration are
i. The complete oxidation of pyruvate by the step-wise removal of all the hydrogen
atoms with the release of three molecules of carbon dioxide.
ii. The passing on the electrons removed as part of the hydrogen atoms to molecular
O2 along with the synthesis of ATP.
The first step takes place in the matrix of the mitochondria, while the second step
occurs in the inner membrane of the mitochondria.
21. Net products of glycolysis:
i. In glycolysis, two molecules of ATP are consumed during double phosphorylation of
glucose to form fructose 1, 6 biphosphate.
ii. Four molecules of ATP are produced by substrate-level phosphorylation
(conversion of 1, 3 biphosphoglycerate to 3-phosphoglycerate and
phosphoenolpyruvate to pyruvate).
iii. Two molecules of NADH2 are formed at the time of oxidation of glyceraldehyde 3-
phosphate to 1, 3 biphosphoglycerate.
iv. The net reaction is as follows:
Glucose + 2NAD + + 2 ADP + 2H PO 2 pyruvate + 2 NADH + 2H + + 2 ATP
4 3
v. Each NADH is equivalent to 3 ATP, so that the net gain in glycolysis is 8 ATP.
Page 5
CBSE XI | BIOLOGY
Sample Paper – 1 Solution
CBSE
Class XI Biology
Sample Paper – 1 Solution
SECTION A
1. Male – Antheridia; Female – Oogonia
OR
Bryophytes can live on land but depend on water for sexual reproduction. Hence,
bryophytes are called amphibians of the plant kingdom.
2. When the leaf base expands into a sheath covering the stem partially or wholly, it is
called a sheathing leaf base.
3. The nucleolus is the site of active ribosomal RNA synthesis.
4. They are specific for a substance.
OR
Catalase catalyses the breakdown of hydrogen peroxide into water and oxygen.
5. Bowman’s capsule
SECTION B
6. Cnidarians exhibit two body forms—polyp and medusa.
Polyp Medusa
i. The polyp form is sessile and cylindrical.
ii. Example: Hydra
i. The medusa form is umbrella-shaped and
free-swimming.
ii. Example: Aurelia
7. The amount of imbibition depends on
i. The water potential gradient between the adsorbent and the liquid/water imbibed.
ii. The affinity between the absorbent and the imbibed liquid.
OR
Sinks for mineral elements or ions in plants:
? Apical and lateral meristems
? Young leaves
? Storage organs
? Developing flowers, fruits and seeds
CBSE XI | BIOLOGY
Sample Paper – 1 Solution
8. They absorb the different wavelengths of light and pass on the energy to the reaction
centre.
9.
(a) Watson and Crick proposed the double helical model of DNA.
(b) The two strands are antiparallel because they run in opposite directions, one in the
5'–3' direction and the other in the 3'–5' direction.
OR
i. Freely in the cytoplasm
ii. Attached to ER in the cytoplasm
iii. Inside mitochondria
iv. Inside plastids
10. Differences between red algae and brown algae:
Red algae Brown algae
1. They have a characteristic pigment
– phycoerythrin.
1. They have a characteristic pigment
– fucoxanthin.
2. They do not have any flagellated or
motile structures.
2. They have flagellated gametes and
zoospores.
3. Reserve food material is in the form
of floridean starch.
3. Reserve food material is in the
form of laminarin and mannitol.
4. Agar and carrageen are the
phycocolloids.
4. Algin is the phycocolloid.
11.
i. stores starch in potato - Parenchyma
ii. forms the shell in nuts - Sclerenchyma
12. Amino acids in a protein are held together by a peptide bond which is formed when the
carboxyl (-COOH) group of one amino acid reacts with the amino (-NH2) group of the
next amino acid with the elimination of a water molecule.
SECTION C
13. Double fertilisation is unique to angiosperms. In this phenomenon, two male gametes
are discharged by a pollen tube into the embryo sac of an ovule. One male gamete fuses
with the female gamete to form a zygote. This fusion is called syngamy. A second male
gamete fuses with the secondary nucleus to form the primary endosperm nucleus. This
is called triple fusion.
CBSE XI | BIOLOGY
Sample Paper – 1 Solution
14. The underground parts of a plant are not always roots because
i. Plants such as potato, ginger, onion and Colocasia have underground stems.
ii. Underground stems show nodes and internodes.
iii. They also have terminal buds and axillary buds.
OR
Characteristics of the cells in the region of the meristem in roots:
? Small in size
? Thin-walled
? Dense protoplasm
? Divide repeatedly
15.
i. The pericycle is positioned just inner to the endodermis.
ii. The protoxylem elements are towards the external surface, while the metaxylem
elements are found towards the core.
iii. Such an arrangement of the xylem is called exarch.
16. Alimentary canal of cockroach:
17. The cytoskeleton is an elaborate network of filamentous proteinaceous structures
present in the cytoplasm.
Functions of the cytoskeleton:
i. Cytoskeletal structures maintain the shape of the cell and its extensions.
ii. It regulates the orientation and distribution of cell organelles.
iii. It helps in the intracellular transport and movement of cells.
OR
CBSE XI | BIOLOGY
Sample Paper – 1 Solution
Differences between primary cell wall and secondary cell wall:
Primary cell wall Secondary cell wall
? It is the cell wall of young cells. ? It is the cell wall formed inner to the
primary wall in older cells.
? It is traversed by plasmodesmata. ? It is traversed by pits.
? It is made of mainly cellulose. ? It is made of lignin, pectin and
suberin.
18.
i. The four microspores formed by meiosis in a microspore mother cell are equal.
ii. The four spermatids formed from a spermatocyte are equal.
iii. When a primary oocyte undergoes meiosis I, a large secondary oocyte and a small
cell, the polar body, are formed.
19.
i. Monoglyceride is a lipid with one molecule of glycerol and one molecule of fatty
acid.
ii. Diglyceride is a lipid with one molecule of glycerol and two molecules of fatty acids.
iii. Triglyceride is a lipid with one molecule of glycerol and three molecules of fatty
acids.
20. The important events in aerobic respiration are
i. The complete oxidation of pyruvate by the step-wise removal of all the hydrogen
atoms with the release of three molecules of carbon dioxide.
ii. The passing on the electrons removed as part of the hydrogen atoms to molecular
O2 along with the synthesis of ATP.
The first step takes place in the matrix of the mitochondria, while the second step
occurs in the inner membrane of the mitochondria.
21. Net products of glycolysis:
i. In glycolysis, two molecules of ATP are consumed during double phosphorylation of
glucose to form fructose 1, 6 biphosphate.
ii. Four molecules of ATP are produced by substrate-level phosphorylation
(conversion of 1, 3 biphosphoglycerate to 3-phosphoglycerate and
phosphoenolpyruvate to pyruvate).
iii. Two molecules of NADH2 are formed at the time of oxidation of glyceraldehyde 3-
phosphate to 1, 3 biphosphoglycerate.
iv. The net reaction is as follows:
Glucose + 2NAD + + 2 ADP + 2H PO 2 pyruvate + 2 NADH + 2H + + 2 ATP
4 3
v. Each NADH is equivalent to 3 ATP, so that the net gain in glycolysis is 8 ATP.
CBSE XI | BIOLOGY
Sample Paper – 1 Solution
OR
i. It is absorbed as NO3
-
, NO2
-
and NH4
+
ions.
ii. It is required in the meristematic tissues and metabolically active cells.
iii. It is a constituent of nucleic acids, amino acids, vitamins, proteins etc.
22.
i. The thoracic chamber is a closed chamber. It is formed dorsally by the vertebral
column. The ventral side is formed by the sternum. It has ribs on the lateral side,
and the lower side is formed by a dome-shaped diaphragm.
ii. It is necessary because any change in the volume of the thoracic cavity will be
reflected in the pulmonary cavity.
iii. The larynx is called the sound box because it has vocal cords which vibrate to
produce sound.
23.
i. Progesterone helps to maintain pregnancy.
ii. It stimulates the secretion of milk.
iii. Its secretion is influenced by the luteinising hormone of the anterior pituitary.
OR
Activities regulated by oestrogen hormone:
? Growth and functions of the female secondary sex organs
? Appearance of female sexual characters
? Development of mammary glands
? Development of ovarian follicle
? Female sexual behaviour
24. Factors affecting the rate of diffusion:
? Concentration gradient
? Permeability of the membrane
? Properties of the substance
? Temperature
? Pressure
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