CBSE Sample Papers for Class 11 Biology Set 6 with Solutions

students must start practicing the questions from CBSE Sample Papers for Class 11 Biology with Solutions Set 6 are designed as per the revised syllabus.

CBSE Sample Papers for Class 11 Biology Set 6 with Solutions

Time Allowed : 3 hours
Maximum Marks: 70

General Instructions :

  1. All questions are compulsory.
  2. The question paper has four sections: Section A, Section B, Section C and Section D. There are 27 questions in the question paper.
  3. Sedion-A has 5 questions ofl mark each. Section-B has 7 questions of 2 marks each. Section-C has 12 questions of 3 marks each and Section-D has 3 questions of 5 marks each.
  4. There is no overall choice. However, internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions.
  5. Wherever necessary, neat and properly labelled diagrams should be drawn.

Section – A

Question 1.
is the most important gibberellins.
(A) GA1
(B) GA2
(C) GA3
(D) GA4
Answer:
(C) GA3

CBSE Sample Papers for Class 11 Biology Set 6 with Solutions

Question 2.
Which antibody factor is responsible for this type of arthritis?
(A) IgE
(B) IgM
(C) Both (A) and (C)
(D) IgA
Answer:
(B) IgM

Question 3.
The tertiary structure of a protein contains
(A) Hydrogen bonds
(B) Peptide bonds
(C) Ionic bonds and S-linkage
(D) All the above
Answer:
(D) All the above

Explanation:
Tertiary Structure of protein is maintained by several types of bonds such as hydrogen bonds, ionic bonds, sulphide bonds and hydrophilic and hydrophobic bonds formed between are part of polypeptide and another.

Direction (Qs. 4 & 5): In the above questions the Assertions (A) and Reasons (R) have been put forward. Read both the statements and choose the correct option from the following:

Question 4.
Assertion (A): Moss protonema resemble green alga.
Reason (R): It develops unicellular sex-organs.
(A) Both A and R are true and R is the correct explanation of A.
(B) Both A and R are true but R is NOT the correct explanation of A.
(C) A is true but R is false.
(D) A is false but R is true.
Answer:

Question 5.
Assertion (A): Elaioplast is a kind of leucoplast.
Reason (R): It is involved in storage of oils and fats.
(A) Both A and R are true and R is the correct explanation of A.
(B) Both A and R are true but R is NOT the correct explanation of A.
(C) A is true but R is false.
(D) A is false but R is true.
Answer:

Section – B

Question 6.
Distinguish between a dicot and a monocot leaf.
Answer:

Dicot leaf Monocot leaf
(i) It is a dorsoventral leaf. It is an isobilateral leaf
(ii) Stomata are found only the on lower epidermis. Stomata are found both on the lower and upper epidermis.
(iii) Reticulate leaf venation. Parallel leaf venation.
(iv) Mesophyll is differentiated into spongy and palisade tissues. The mesophyll is not divided into spongy and palisade tissues.
e.g., Dicot plants. e.g., Monocot plants.

Question 7.
What is Glycolysis? Where does it occur?
Answer:
Glycolysis is also called as EMP (Embden Meyerhof Parnas) pathway. Glycolysis is the process of breakdown of glucose or similar hexose sugar into two molecules of pyruvic add through a series of enzyme-mediated reactions releasing some energy (ATP) and reducing power (NADH). It occurs in cytosol or cytoplasm.

Question 8.
What are the assumptions made during the calculation of net gain of ATP?
Answer:
Assumption:

  1. There is a sequential, orderly pathway functioning with one substrate forming the next via glycolysis, Krebs’s cycle and ETS.
  2. NADH synthesized in glycolysis is transferred into mitochondria and undergoes oxidative phosphorylation.
  3. None of the intermediates in the pathway are used to make any other compound.
  4. Only glucose is being respired. No other alternative substrate enters the pathway at any intermediate stage.

CBSE Sample Papers for Class 11 Biology Set 6 with Solutions

Question 9.
Write a short note on chitin.
OR
What are waxes and how they differ from paraffin waxes?
Answer:

  1. Chitin is the second most abundant organic compound in nature.
  2. It is a fibrous homopolysaccharide of high tensile strength.
  3. Its basic unit is a nitrogen-containing glucose derivative known as N-acetyl glucosamine.
  4. Chitin is soft and leathery, it provides both strength and elasticity. It becomes hard when impregnated with calcium carbonate

OR
Waxes are the fatty acid esters of long-chain monohydric alcohols like cetyl, ceryl or myricyl. However, paraffin wax is obtained from petroleum. Plant waxes occur in cuticles whereas animals have cutaneous glands which are known to secrete wax

Question 10.
What is stroke volume? How is it related to cardiac output?
Answer:
During cardiac cycle or one heartbeat, the volume of blood pumped by the heart is called stroke volume. This is normally 70 ml. The amount of blood pumped by the heart per minute is called the cardiac output. It is the product of stroke volume and the number of heart beats.

Question 11.
What are the functions of Hypothalamus?
Answer:

  1. Hypothalamus integrates and controls the visceral activities.
  2. It maintains homeostasis.
  3. It provides anatomical connection between the nervous and endocrine systems by its relationship to the pituitary gland.
  4. Hypothalamus is the thermoregulatory centre. Hence it is called “thermostat” of the body. It keeps body temperature at roughly 37°C by means of a complex thermostat system.
  5. It is also associated with behavioural activities.
  6. Appetite and thirst centres are located in the hypothalamus.

Question 12.
Why colchicine is called as the mitotic poison?
Answer:

  1. Colchicine is an alkaloid obtained from the corms of Colchicum autumnale. The alkaloid inhibits the formation of spindle by preventing assembly of microtubules.
  2. The chromosomes duplicate but they remain within the same cell, increasing the number of chromosomes. As a result, the colchicine treated meristematic cells show doubling of chromosome.

Section – C

Question 13.
How monerans utilize different strategies to get their food? Explain.
Answer:
Monerans utilise different strategies to get their food:
(i) Some of the monerans (bacteria) are autotrophic that is, they synthesize their own food from inorganic substrates. They may be photosynthetic autotrophic or chemosynthetic autotrophic.

(ii) Chemosynthetic bacteria oxidise various inorganic substances such as nitrates, nitrites and ammonia and use the released energy for ATP production.

(iii) Bacteria that derive their nutrients from dead remains of plants and animals £re called saprophytes.

(iv) Bacteria that draw nutrients from the body of other living organisms are called parasites.
Bacteria that live in association with other living organisms and derive nutrients from them without causing them harm are called symbionts. During this association, both the organisms are mutually benefitted from each other.

Question 14.
Briefly explain the Tricarboxylic Add Cycle.
OR
Define in brief the Cyclic and Non-cyclic photo-phosphorylation. one type to another.
Answer:
(i) TCA cycle was discovered by Hans Krebs in 1940. This cycle is called TCA cycle because initial product is citric add.

(ii) Acetyl CoA combine with OAA (Oxaloacetic add) and water to yield citric add in presence of enzyme dtrate synthase to release CoA.

(iii) A molecule of glucose produces two molecules of NADH, 2ATP and two pyruvate while undergoing glycolysis. The two molecules of pyruvate are completely degraded in Kreb’s cycle to form two molecules of ATP 8NADH and 2FADH2
Pyruvic add + 4NAD+ + FAD+ + 2H2O + ADP + Pi CBSE Sample Papers for Class 11 Biology Set 6 with Solutions 1. 3COH2 + 4NADH+ 4H+ +FADH2 + ATP
OR

  1. The process of synthesis of ATP from ADP and inorganic phosphate in the presence of light is known as photophosphorylation.
  2. When the two photosystems work in a series first PS II and then PS I, a process called non-cyclic photophosphorylation occurs. The two photosystems are connected through an eledron transport chain.
  3. When only PS I is functional, the electron is circulated within the photosystem and the phosphorylation occurs due to the cyclic flow of electrons.
  4. Cyclic photophosphorylation also occurs when only light of wavelength beyond 680 nm is available for education.

CBSE Sample Papers for Class 11 Biology Set 6 with Solutions

Question 15.
Are the different types of plastids interchangeable? If yes, give examples where they are getting converted from one type of another.
Answer:
Yes, plastids are interchangeable in their form. Generally, three types of plastids are present in plant cells, i.e.,
leucoplasts, chromoplast and chloroplasts. Depending upon the condition and maturity stage, one type of plastid can get converted into another plastid.
For example:

  1. In Capsicum, the cells of the ovary consist of leucoplasts. When ovary changes into fruit, leucoplasts are
    transformed into chioroplasts. When the fruit ripens, chioroplast is converted into chromoplast.
  2. In stem tubers of potato, the leucoplast, on exposure to sunlight transform into chioroplasts.
  3. In some cases, the chioroplast gets converted into chromoplast during ripening of fruits, e.g., change of colour from green to red during ripening of tomato and chili.

Question 16.
Enlist four steps involved in catalytic action of an enzyme.
Answer:
Steps of catalytic cycle of an enzyme action are:

  1. The substrate binds to the active site of the enzyme.
  2. This binding of the substrate induces the enzymes to alter its shape and fit more dosely around the substrate.
  3. The active site of the enzyme, now is in close proximity to the substrate breaks the chemical bonds of the
    substrate and an enzyme-product complex is formed.
  4. The enzyme releases the products of the reaction and the free enzyme is ready to take up another molecule of the substrate.

Question 17.
Differentiate between Pectoral and pelvic girdle.
Answer:

Pectoral girdle Pelvic girdle
(i) It is found in the shoulder region, hence also known as shoulder girdle. It occurs in the hip region, hence also known as hip girdle
(ii) It is a skeletal support from where the fore limbs of vertebrates are attached. It is a skeletal support from where the hind limbs of vertebrates are attached.
(iii) It is composed of two bones namely, clavicle or collar bones and scapula or shoulder bone. It is composed of three bones, upper ileum, inner pubic, and ischium.
(iv) Each pectoral girdle has a glenoid cavity into which the head of the humerus is articulated. Each pelvic girdle has a deep depression called acetabulum to which the head of the femur is articulated.

Question 18.
How nerve impulses are conducted in non-myelinated nerves.
Answer:
Conduction of nerve impulse through non-myelinated nerves:

  1. in resting stage, the Na ions are pumped out from the axoplasm. It needs energy to work normally.
  2. Thus axon membrane is electronegative inside and electropositive outside, this is called resting potential. In this state, the nerve is said to be in polarised state.
  3. When the nerve fibre is stimulated, it causes electrochemical disturbance in the nerve fiber, a change in potential. This change is called an action potential.
  4. Thus, Na + migrate into the axoplasm and Cl- ions diffuse out. Thus, negativity is increased outside and positivity is increased inside. This is called depolarisation
  5. Depolarisation progresses along the nerve fiber in both directions from the point of stimulus.

Question 19.
How can you distinguish hypothyroidism and hyperthyroidism?
OR
Name the source gland of luteinising hormone (LH). Mention the other hormone along with which it acts on its target cells/ organ. Give their two functions.
Answer:

  1. Hyperthyroidism is increased levels of thyroid hormones whereas hypothyroidism is decreased levels of thyroid hormones.
  2. Hyperthyroidism can lead to Grave’s disease whereas hypothyroidism does not produce this disease.
  3. There is faster metabolism in hyperthyroidism while there is a slow metabolism in hypothyroidism.
  4. Hypothyroidism is treated by supplements of thyroid hormones and hyperthyroidism is treated by anti-thyroid drugs.
  5. Hypothyroidism shows decreased levels of T, and T4 and increased levels of TSH whereas in hyperthyroidism, there is an increased level of T3 and T4 and a decreased level of TSH.

OR
LH is secreted by the adenohypophysis or anterior pituitary gland. FSH is the other hormone (gonadotropin) along with which its target cell.

Functions of LH:

  • In males, it stimulates spermatogenesis.
  • In females, it stimulates ovulation and the formation of the corpus luteum.

Functions of FSH: In females, it stimulates the growth of ovarian follicles.

CBSE Sample Papers for Class 11 Biology Set 6 with Solutions

Question 20.
For completion of respiration process, write the given steps in a sequential manner

  1. Diffusion of gases (O2 and CO2) across the alveolar membrane.
  2. Transport of gases by blood.
  3. Utilisation of O2 by the cells for catabolic reactions and resultant release of CO2.
  4. Pulmonary ventilation by which atmospheric air is drawn in and CO2 rich alveolar air is released out.
  5. Diffusion of O2 and CO2 between blood and tissues.

Answer:
The correct sequence is: (iv) – (i) – (ii) – (v) – (iii)

  1. Pulmonary ventilation by which atmospheric air is drawn in and CO2 rich alveolar air is released out.
  2. Diffusion of gases (O2 and CO2) across the alveolar membrane.
  3. Transport of gases by blood.
  4. Diffusion of O2 and CO2 between blood and tissues.
  5. Utilisation of O2 by the cells for catabolic reactions and resultant release of CO2

Question 21.
State the rules for Writing Sdentific Names.
Answer:
Rules for Writing Scientific Names:

  1. Biological names are generally in Latin or Latinised.
  2. The first word in a scientific name denotes the generic name while the second word represents the specific epithet.
  3. The first word representing the generic name starts with a capital letter while the specific name is written with a small letter. It can be illustrated with the example of Mangifera indica.
  4. Both the words in a scientific name when handwritten are separately underlined or printed in italics.
  5. At the end of the biological name, i.e., after the specific epithet, the name of the author is written in an abbreviated form, e.g., Mangifera indica Linn.

Question 22.
Distinguish between taxonomy and systematics.
OR
Compare between the Chordates and Non-chordates.
Answer:
Difference between Taxonomy and systematics:

Taxonomy Systematics
(i) It is the study of organisms on the basis of their characteristics. It is the study of diversity of organisms and all their comparative and evolutionary relationships.
(ii) ft includes morphological and anatomical features for identification. It deals with comparative anatomy, ecology, physiology, phylogenetics and biochemistry.
(iii) Taxonomy is limited. Systematics is the broad field of biology.

OR
Chordates vs. Non-chordates

Chordates Non-chordates
(i) Notochord is present and the heart is ventral. The notochord is absent and heart is dorsal.
(ii) CNS is dorsal, hollow and single. CNS is ventral, solid and double.
(iii) Pharynx perforated by gill slits. Gill slits are absent.
A post-anal part is present. Post anal tail is absent.

Question 23.
Give the possible reason for the following statements.

  1. A transparent nictitating membrane is present in the eyes of a frog.
  2. The first finger of the male frog is swollen.
  3. Webs are present between the toes of frog.

Answer:

  1. The nictitating membrane protects the eyes of the frog when it goes into mud during hibernation, aestivation and swimming.
  2. The first finger in the male frog is swollen in the form of a copulatory pad to hold up the female frog firmly during copulation.
  3. The webs are present between the toes because these act as paddles when the frog is swimming.

Question 24.
Briefly describe Gl-phase of cell cyde.
Answer:
G1 Phase: (Post-Mitotic Gap 1)
(a) It includes synthesis and organisation of the substrate and enzyme necessary for DNA synthesis.
(b) It is marked by the transcription of r-RNA, t-RNA, m-RNA and synthesis of different proteins.
(c) Enlargement of the nucleus.
(d) Pooling of nucleotide and protein from the neighbouring cell into dividing cell.
(e) The chromosomes lie in the form of more or less loosely coiled thread.

CBSE Sample Papers for Class 11 Biology Set 6 with Solutions

Section – D

Question 25.
Read the following to answer any four questions from (i) to (iii) given below:
Xylem functions as a conducting tissue for water and minerals from roots to the stem and leaves. It also provides mechanical strength to the plant parts. It is composed of four different kinds of elements, namely, tracheids, vessels, xylem fibres and xylem parenchyma. Gymnosperms lack vessels in their xylem. Tracheids are elongated or tube-like cells with thick and lignified walls and tapering ends. These are dead and are without protoplasm.

The inner layers of the cell walls have thickenings which vary in form. In flowering plants, tracheids and vessels are the main water transporting elements. Vessel is a long cylindrical tube-like structure made up of many cells called vessel members, each with lignified walls and a large central cavity. The vessel cells are also devoid of protoplasm. Vessel members are interconnected through perforations in their common walls. The presence of vessels is a characteristic feature of angiosperms. Xylem fibers have highly thickened walls and obliterated central lumens. These may either be septate or aseptate.

Xylem parenchyma cells are living and thin-walled, and their cell walls are made up of cellulose. They store food materials in the form of starch or fat, and other substances like tannins. The radial conduction of water takes place by the ray parenchymatous cells. Primary xylem is of two types – protoxylem and metaxylem. The first formed primary xylem elements are called protoxylem and the later formed primary xylem is called metaxylem. In stems, the protoxylem lies towards the center (pith) and the metaxylem lies towards the periphery of the organ. This type of primary xylem is called endarch. In roots, the protoxylem lies towards periphery and metaxylem lies towards the center. Such arrangement of primary xylem is called exarch. (5×1=5)

  1. Which part of the xylem is not present in Gymnosperms.
  2. What are the different types of primary xylems.
  3. What is the difference between protoxylem in stem and protoxylem roots?
  4. Why xylem is called a dead tissue?
  5. Briefly describe the structure of vessels?

Answer:

  1. Gymnosperms lack vessels in their xylem.
  2. Primary xylem is of two types – protoxylem and metaxylem.
  3. In stems, the protoxylem lies towards the centre (pith) and in roots, the protoxylem lies towards the periphery.
  4. Except for Xylem parenchyma, all other parts are dead in Xylem tissue so it is called dead tissue.
  5. Vessel is a long cylindrical tube-like structure made up of many cells called vessel members, each with lignified walls and a large central cavity. The vessel cells are also devoid of protoplasm. Vessel members are interconnected through perforations in their common walls.

Question 26.
What are the external and internal factors affecting photosynthesis?
OR
(a) What is differentiation? How can you distinguish between dedifferentiation and redifferentiation?( 3+2)
(b) Distinguish between plant and animal growth.
Answer:
The external and internal factors affecting photosynthesis are :
(i) External factors:
(a) Light : The quality, intensity and duration of light received by plants greatly influences the rate of photosynthesis. The quality of light influences the photosynthesis as blue and red regions of the visible spectrum are most effective. The green light has a minimum effect. When the sufficient intensity of light is available, they start performing photosynthesis. Rate of photosynthesis increase proportionately with in increase in light intensity till plants achieve light saturation point. Beyond this point photosynthesis does show any change. Longer exposure to continuous light favours good photosynthesis.

(b) Carbon dioxide: CO2 concentration in atmosphere act as a limiting factor. An increase in CO2 cone, upto 0.1 % shows an increase in photosynthesis. Higher cone, becomes toxic and inhibit the rate of photosynthesis.

(c) Oxygen: High concentration of oxygen has an inhibitory effect on photosynthesis in C3 plants, because RuBP oxygenase becomes more active resulting in photorespiration.

(d) Water: Its photooxidation supplies H+ for the reduction of NADR The reduced NADPH is used in the reduction of CO2 in Calvin cycle. It also donates the electrons to P680 in non-cyclic photophosphorylation.

(e) Temperature: Rate of photosynthesis doubles with every 10°C rise in temperature till the optimum value is achieved. An increase in temperature above 30°C results in a fall in the rate of photosynthesis. The optimum temperature for photosynthesis in C3 plants is 10-25°C and in C4 plants it is 30-45°C.

(ii) Internal factors:
(a) Chlorophyll content: Chlorophyll is essential for cyclic and non-cyclic photophosphorylation and reduction of NADR the assimilatory power, used to fix and reduce CO2 in Calvin cycle.

(b) Leaf anatomy: The important anatomical features that influence photosynthesis include thickness of cuticle, stomatal index, distribution of stomata, degree of opening of stomata, size and distribution of intercellular spaces, and number and distribution of vascular strands. Kranz anatomy of C4 plants increases the efficiency of photosynthesis.

(c) Age of leaf: As leaf develops, the rate of its photosynthesis increases gradually reaching maximum when the leaf becomes fully matured. Rate of photosynthesis decreases with age of leaf.
OR
(a) The cells which are derived from root apical meristem and shoot apical meristem differentiate and mature to
perform specific functions. This act leading to maturation is termed as differentiation. During this, the cells
undergo a few major structural changes both in their cell walls and protoplasm.
(i) In plants, the living differentiated cells can regain the capacity to divide mitotically under certain conditions. The sum of events are termed as dedifferentiation. A dedifferentiated tissue can act as meristem. e.g. interfascicular vascular cambium, cork cambium and wound meristem.

CBSE Sample Papers for Class 11 Biology Set 6 with Solutions

(ii) The product of dedifferentiated cells or tissues which lose the ability to divide are called redifferentiated ceEs and the term is known as redifferentiation. Secondary xylem and secondary phloem that form interfascicular vascular cambium, secondary cortex and cork are examples of redifferentiated tissues
(b)

Plant growth Animal growth
(i) Plant growth occurs only in meristematic zones. In animal growth, almost all the cells increase in size.
(ii) Plant growth is constructed in a modular fashion. Development is open-ended and their structure are never complete. Embryonic growth is completed quite early, but mature size may be reached at specific periods.
(iii) Firstly, growth is uniform but later it becomes irregular. Animals grow in a synchronous and well-defined way.
(iv) The growth is unrestricted ed and diffused. The growth is restricted ed and not diffused.
(v) The freshly formed seedling cannot be called a miniature plant The young animal looks like a miniature version of the adult

Question 27.
Read the following to answer any four questions from (i) to (v) given below: (5×1=5)
Amphibians are the first tetrapods to invade the land. The juvenile phase of the life cycle is dependent on water, where gas exchange occurs through gills. Amphibians have aquatic larval life and terrestrial adult life. Respiration is by gills, lungs and skin. Their body is divisible into head and trunk and skin is moist without scales. The two pairs of limbs are used for locomotion except for caecilians.

They are cold- blooded animals. Respiration is by gills (in larva); lungs and skin (in adults). Amphibians have a three-chambered heart. Fertilisation is external. However, in Salamander and Ichtyophis fertilisation is internal. They are mostly oviparous, except for Salamander, which is viviparous. Development is indirect. (1+2+2)

(i) Amphibians are cold- blooded animals hence, they are called animals.
(A) Homeothermic
(B) Homoiothermic
(C) Poikilotherms
(D) Homothermic
Answer:
(C) Poikilotherms
Explanation:
They are cold-blooded animals. Their body temperature vary with the varying environment.

(ii) All amphibians use two pairs of limbs for locomotion, however, is a limbless amphibia.
(A) Bufa
(B) Salamandra (Salamander)
(C) Hyla
(D) Ichthyophis
Answer:
(D) Ichthyophis
Explanation:
It is an unusual amphibian. They have worm like body without legs. Limbless amphibians are also named as caecilians.

CBSE Sample Papers for Class 11 Biology Set 6 with Solutions

(iii) In some amphibians even after attaining sexual maturity, larval characters are retained. It is known as
(A) Phylogenesis
(B) Neoteny
(C) Parthenogenesis
(D) Ontogenesis
Answer:
(B) Neoteny
Explanation:
It is the retention of juvenile features in the adult animal, or the sexual maturity of an animal while it is still is a larval state.