CBSE Sample Papers for Class 11  Biology Solved 2016 Set 5

Section – A

1. Name the tissue that causes grittiness in the fruits, e.g. pear.[1]
2. Explain the interphase.[1]
3.State the role of leghaemoglobin in root nodules of leguminous plants.[1]
4.When C02 is added to PEP name the first stable product synthesised.[1]
5.Which group of fungi are called ‘fungi imperfecti’?[1]

Section – B

6.Differentiate between tendons and ligaments.
7.Explain the phenomena of apical dominance. Name the hormone responsible for it.[2]
8.Why do cold-blooded animals have higher amount of unsaturated fatty acids than warm-blooded animals?[2]
9.Write a short note on muscle twitch.[2]
or
Give one word for the following.
(i)Blood filled cavity in arthropods
(ii)Excretory organs of an annelid
(iii)Stinging cells of jellyfish
(iv)Animals having reproductive organs of both sexes

Section – C

10.Do you consider a person in coma-living or dead?[3]
11.Define the term ‘inflorescence’. List some differences between racemose and cymose kind of inflorescence.[3]
12.How useful is the study of the nature of body cavity and coelom in the classification of animals?[3]
13.(a) Why is Golgi apparatus named so?
(b)Define dictyosome. State the difference between the Golgi apparatus of plants and animals.
14.In a way green plants and cyanobacteria have synthesised all the food on the earth. Comment. [3]
or
What are the advancements of arthropods over annelids? Give an account of respiratory organs in arthropods. [3]
15.Briefly describe
(a)Numerical taxonomy[3]
(b)Chemotaxonomy [3]
16.How is glomerular filtrate and urine different in composition?[3]
17.Explain how a competitive inhibitor affects the activity of an enzyme?  [3]
18.Answer briefly –
(a)How do you perceive the colour of an object?
(b)Which part of our body helps us in maintaining the body balance?
19.Why a large number of stomata are present at the lower surface of the dicotyledonous leaves in the terrestrial plants?[3]
20.On an educational trip to Uttaranchal, Ketki and her friends observe that many local people were having swollen necks, please help Ketki and her friends to find out the solutions to the following questions.
(a)Which probable disease are these people suffering from?
(b)How is it caused?
(c)What effect does this condition have on pregnancy?
21.Once Kunal’s class went to an educational tour from his school. There they visited a leather goods manufacturing industry. They learnt and observed that leather was made from skin of various animals by tanning. He was amazed to see it and asked a lot many questions out of curiosity. But, after learning the whole process concluded and convinced them that it was unethical and illegal to use animals for such purposes.
(a)Which tissues are involved in manufacture of leather?
(b)What characteristic features of this tissue are advantageous in obtaining leather from it?
(c)Name any two other features of this tissue.
(d)What values are reflected by Kunal?

Section – D 

22.Describe the types of dowers, classified on the basis of relative positions of floral organs or parts on tbalamu’ Explain with the help of diagram.
or
Differentiate between the following,
(a)C3 and C4 pathways
(b)Cyclic and non-cyclic photophosphoryla.
23.Give an account of synovial joints.
or
Lichen is usually cited as an example of ‘symbiosis’ in plants where an algal and a fungal species live together for their mutual benefit. Which of the following will happen if algal and fungal partners are separated from each other? Explain.
(a)Both will survive and grow normally and independent from each other.
(b)Both will die.
(c)Algal component will survive while the fungal component will die.
(d)Fungal component will survive while algal partner will die.
Based on your answer how do you justify this association as symbiosis?

Answers

Section – A

1. Name the tissue that causes grittiness in the fruits, e.g. pear.[1]
Ans. Dead sclerenchymatous cells called sclereids are present in the pulp of fruits, e.g. pear. These are unbranched, short and isodiametric cells with ramiform pits called stone cells or brachysclereids .The cause grittiness in the fruit.

2. Explain the interphase.[1]
Ans. Interphase represent the phase between two successive M-phase or mitosis phase. The interphase lasts for more than 95% of the duration of cell cycle. This phase is divided into three further phases, i.e.G1,S and G2-phases.

3.State the role of leghaemoglobin in root nodules of leguminous plants.[1]
Ans. Leghaemoglobin is a oxygen scavenger protein, found in root nodules of those, leguminous plants, colonised by Rhizobium. It is structurally related to blood haemoglobin and has a high affinity for oxygen. It protects the nitrogen-fixing enzyme nitrogenase from high oxygen concentrations, which reduces the activity of enzyme.

4.When C02 is added to PEP name the first stable product synthesised.[1]
Ans. Oxaloacetate is a four carbon compound formed in C4 plants and is a first stable product, that is why such plants are called C4 plants.

5.Which group of fungi are called ‘fungi imperfecti’?[1]
Ans. The group of fungi placed in class-Deuteromycetes does not bear sex organs and therefore do not show sexual reproduction. This makes them different from other groups of true fungi that exhibit both asexual and sexual modes of reproduction. Hence, named ‘fungi imperfecti’, e.g. Trichoderma.

Section – B

6.Differentiate between tendons and ligaments.
Ans.
cbse-sample-papers-for-class-11-biology-solved-2016-set-5-1

7.Explain the phenomena of apical dominance. Name the hormone responsible for it.[2]
Ans. The phenomenon by which the presence of apical buds prevents the growth of lateral buds, is called apical dominance. Apical bud inhibits the growth of lateral buds by releasing hormones called auxins. Removal of apical buds allows the growth of lateral buds, making, the plant bushy and dense.

8.Why do cold-blooded animals have higher amount of unsaturated fatty acids than warm-blooded animals?[2]
Ans. As cold-blooded animals cannot maintain an internal constant body temperature like warm-blooded animals, they possess higher amount of unsaturated fatty acids. More number of unsaturated fatty acids (having a bend at each double bond) makes them more disordered that helps to maintain a fluid state at low temperatures and preventing them from freezing at extremely low temperature. Also, these fatty acids form thick subcutaneous fatty layer for insulation.

9.Write a short note on muscle twitch.[2]
or
Give one word for the following.
(i)Blood filled cavity in arthropods
(ii)Excretory organs of an annelid
(iii)Stinging cells of jellyfish
(iv)Animals having reproductive organs of both sexes  
Ans. A muscle fibre when stimulated by a single nerve impulse or a single electric shock, undergoes a short period of contraction, followed by immediate short duration of relaxation. This is called muscle twitch or single muscle twitch. It is related to individual muscle fibres. A continuous stimulus is of no use in such case as the muscle fibres during twitch do not recognise the stimulus during its relaxation and refractory periods.
or
The one words for the given statements are:
(i)Blood filled cavity in arthropods-Haemocoel
(ii)Excretory organs of an annelid-Nephridia
(iii)Stinging cells of jellyfish—Cnidoblasts
(iv)Animals having reproductive organs of both sexes-Hermaphrodite

Section – C

10.Do you consider a person in coma-living or dead?[3]
Ans.A coma is a profound or deep state of unconsciousness. The affected person is alive, but is not able to react or respond to life around him/her. Coma may occur due to either prolong illness or head trauma. In this state, the individual loses the higher cerebral power of the brain, but the functions of the brainstem, such as respiration (breathing) and circulation, remain relatively intact.
Spontaneous movements may occur and the eyes may open in response to external stimuli but the patient does not speak or obey commands. Patients in this state may appear somewhat normal as he/she may occasionally grimace, cry or laugh. Thus, keeping these points in mind, we can consider a person in coma as a living dead.

11.Define the term ‘inflorescence’. List some differences between racemose and cymose kind of inflorescence.[3]
Ans. Inflorescence is the arrangement and distribution of flowers on the floral axis.
The differences between racemose and cymose type of inflorescence are:
cbse-sample-papers-for-class-11-biology-solved-2016-set-5-2

12.How useful is the study of the nature of body cavity and coelom in the classification of animals?[3]
Ans. The presence or absence of a cavity between the body wall and the gut wall is very important in classification.
The body cavity which is lined by mesoderm is called coelom.
(i)Animals, possessing coelom are called coelomata, e.g. annelids, molluscs, arthropods, echinoderms, hemichordates and chordates.
(ii)In some animals, the body cavity is not mesoderm, instead the mesoderm is present as scattered pouches in between the ectoderm and endoderm. Such a body cavity is called pseudocoelom and the animals possessing them are called pseudocoelomates, e.g. Aschelminthes.
(iii)The animals in which the body cavity is absent are known as acoelomates, e.g. Platyhelminthes.

13.(a) Why is Golgi apparatus named so?
(b)Define dictyosome. State the difference between the Golgi apparatus of plants and animals.
Ans. (a) Golgi apparatus is named so after the name of an Italian scientist Camillo Golgi, who recognised this apparatus in its reticular form, near nucleus.
(b)The number of unconnected, small units of Golgi complexes scattered throughout the cytoplasm of cell are called dictyosomes. They are usually found in plant cells and many invertebrates.
They differ from Golgi apparatus of animals in size and number. Animals possess a single, large, interconnected complex of Golgi apparatus while variable number of small units are found in plant cells. The Golgi is compact and forms a network between the nucleus and periphery. Its position varies depending on the function of cells. It is localised in secretory cells and diffuse in nerve cells. In plants they are scattered throughout.

14.In a way green plants and cyanobacteria have synthesised all the food on the earth. Comment. [3]
or
What are the advancements of arthropods over annelids? Give an account of respiratory organs in arthropods. [3]
Ans. Cyanobacteria are unicellular prokaryotic organisms. Besides, some primitive cellular cell organelles, they have photosynthetic lamellae where photosynthetic pigments are present. There are chlorophyll-a, c, phycocyanin and phycoerythrin.
These coloured pigments impart typical blue-green colour to the bacteria and enable them to manufacture food for themselves and aquatic animals. Green plants are multicellular organisms capable of making food by using C02, H^O and light energy in special cell organelles called chloroplast. So’, bacteria and green plants make food for living organisms on earth.
or
Arthropods have distinct head, jointed appendages for different functions. Exoskeleton, special respiratory organs, secrete pheromones, sense organs are well-developed. These features are not present in annelids. Respiration in arthropods occurs through general body surface, gills (e.g. prawn), book lungs (e.g. scorpion and spides), trachea (e<g. cockroach) and book gills (e.g. king crab).

15.Briefly describe
(a)Numerical taxonomy[3]
(b)Chemotaxonomy [3]
Ans. (a) Numerical taxonomy It is defined as the numerical evaluation of similarities between group of organisms and organising these groups in higher ranks of taxa, on the basis of these similarities.
In this system, characters of organisms are given equal weightage and the relationship between organisms is numerically determined.
(b) Chemotaxonomy It is a method of classifying organisms on the basis of chemicals obtained from parts of plants or animals. These specific micro or macromolecules are used as evidence in solving the taxonomic puzzles. Also, the nature of proteins and DNA sequencing had contributed a lot in establishing similarities and relationship between organisms.

16.How is glomerular filtrate and urine different in composition?[3]
Ans. The composition of glomerular filtrate and urine is not the same as the glomerular filtrate contains a large amount of water and other dissolved substances such as urea, uric acid, creatinine, amino acid, glucose, sodium, potassium, vitamins, hormones, etc.
Urine on the other hand is a transparent, light yellow fluid which is formed after rigorous reabsorption and secretion from the filtrate. It constitute about 95% of water and 5% of other organic and’inorganic substances.
Organic substances, in urine includes nitrogen, urea, creatine, ammonia, uric acid, oxalic acid, vitamins, hormones and enzymes.
Whereas, inorganic substances in urine include chloride, phosphate, sulphate, potassium, sodium, calcium, magnesium, iodine, arsenic and lead. Glucose is not found in urine normally. Hence, composition of glomerular filtrate and urine is different.

17.Explain how a competitive inhibitor affects the activity of an enzyme?  [3]
Ans. The activity of an enzyme is sensitive to the presence of specific chemicals that bind to the enzyme. When the binding of the chemical shuts off enzyme activity, the process is called inhibition and the chemical is called inhibitor. When the inhibitor closely resembles the substrate in its molecular structure and inhibits the activity of the enzyme it is known as competitive inhibitor.
Due to this the inhibitor competes with the substrate for binding to the enzyme (binding site) consequently, the substrate is unable to bind and inhibitor binds to it. Thus, the overall activity of the enzyme declines, e.g .inhibition of succinic dehydrogenase by malonate.

18.Answer briefly –
(a)How do you perceive the colour of an object?
(b)Which part of our body helps us in maintaining the body balance?
Ans. (a) The daylight (photopic) vision and colour vision are functions of cones. In the human eye, there are three types of cones which possess their own characteristics photopigments that respond to red, green and blue lights. The sensations of different colours are produced by various combinations of these cones and their photopigments. When these cones are stimulated equally, a sensation of white light is produced.
(b) The crista and macula are the specific receptors of the vestibular apparatus of inner ear which are responsible for the maintenance of balance of the body and posture.

19.Why a large number of stomata are present at the lower surface of the dicotyledonous leaves in the terrestrial plants?[3]
Ans. Stomata are minute apertures present on the outer surface of leaf to allow exchange of gases, i.e. C02,02, water vapour from the environment into and out of the leaf.
Stomata opens during day, in the presence of light and its opening leads to influx of C02 and efflux of H2O. During daytime, if a larger number of stomata are present on upper surfdce, more loss of water will take place, resulting in wilting of plants.   ‘
Therefore, to prevent excessive water loss during high light intensities and temperature, large number of stomata are present on lower surface of dicot leaves.

20.On an educational trip to Uttaranchal, Ketki and her friends observe that many local people were having swollen necks, please help Ketki and her friends to find out the solutions to the following questions.
(a)Which probable disease are these people suffering from?
(b)How is it caused?
(c)What effect does this condition have on pregnancy?
Ans. (a) People with swollen necks are suffering from goitre due to deficiency of iodine in the their bodies.
(b)Iodine is essential for the synthesis of thyroid hormones-T3 and T4 which are iodinated forms of thyroxine. Deficiency of iodine in our diet results in hypothyroidism which leads to enlargement of the thyroid gland.  .
(c)Hypothyroidism during pregnancy causes defective development and abnormalities in growing baby like stunted growth (cretinism), mental retardation, low Intelligence Quotient (IQ), abnormal skin deaf-mutism, etc.

21.Once Kunal’s class went to an educational tour from his school. There they visited a leather goods manufacturing industry. They learnt and observed that leather was made from skin of various animals by tanning. He was amazed to see it and asked a lot many questions out of curiosity. But, after learning the whole process concluded and convinced them that it was unethical and illegal to use animals for such purposes.
(a)Which tissues are involved in manufacture of leather?
(b)What characteristic features of this tissue are advantageous in obtaining leather from it?
(c)Name any two other features of this tissue.
(d)What values are reflected by Kunal?
Ans. (a) The tissue involved in manufacture of leather is white fibrous connective tissue.
(b)The features of connective tissue advantageous for obtaining leather are:
(i)Provides strong attachment between various structures.
(ii)The presence of white fibrous tissue of joints between skull bones making it immovable.
(iii)The presence of abundant white fibres permits the skin dermis of mammals to yield leather, after
tanning.
(c)The other features of white connective tissue are:
(i)Rich in white collagen fibres (ii) Very tough and inelastic tissue
(d) ‘e is very kind, intelligent and with strong moral and ethical values.

Section – D 

22.Describe the types of dowers, classified on the basis of relative positions of floral organs or parts on tbalamu’ Explain with the help of diagram.
or
Differentiate between the following,
(a)C3 and C4 pathways
(b)Cyclic and non-cyclic photophosphoryla.
Ans. On the basis of relative position of floral parts on thalamus, flowt, ‘ classified as :
(i)Hypogynous In this flower ovary is situated on the highest positioi,, He, the other parts are situated below it. The ovary is superior, e.g. tomato, brinjal, mustard, China rose, etc.
(ii)Perigynous In this flower thalamus forms a cup-like structure around the ovary and bears the other floral organ. The ovary is half-superior/half inferior, e.g. rose, plum, peach, etc.
(iii)Epigynous In this flower thalamus form a cup and is fused with the ovary and all other floral organs arise on top of the ovary. The ovary is inferior, e.g. guava, cucumber, etc.
cbse-sample-papers-for-class-11-biology-solved-2016-set-5-3
Ans.
cbse-sample-papers-for-class-11-biology-solved-2016-set-5-4
cbse-sample-papers-for-class-11-biology-solved-2016-set-5-5

23.Give an account of synovial joints.
or
Lichen is usually cited as an example of ‘symbiosis’ in plants where an algal and a fungal species live together for their mutual benefit. Which of the following will happen if algal and fungal partners are separated from each other? Explain.
(a)Both will survive and grow normally and independent from each other.
(b)Both will die.
(c)Algal component will survive while the fungal component will die.
(d)Fungal component will survive while algal partner will die.
Based on your answer how do you justify this association as symbiosis?
Ans. Synovial joints are the perfect joints that allows free movements in one or more directions. Depending upon the nature of articulation and degree of movement, they are of following types:
(i)Bali and socket The head of the bone fitting with the socket of other bone allowing movement in all plane, e.g. shoulder and hip joints.
(ii)Hinge joints Allows the movement in one plane. In this articular end of one bone is deeper convex and the other is deeper concave, e.g. elbow joint and knee joint.
(iii)Pivot joints (rotatory) One of the two bone gets fixed and other one rotate on the fixed one, e.g. atlas.
(iv)Saddle joints Similar to ball and socket joints but both ball and socket are poorly developed and movement is comparatively less free, e.g. metacarpal and carpal.
(v)Gliding joints The joints which permits the sliding of the articulating bones on each other, e.g. joint between the radius-ulna and carpal.
(vi)Angular or ellipsoidal joints These joints allows the movement in two directions, i.e. side to side and back and front, e.g. wrist joints.
or
(b) If one of the partners are separated from the association, both will die, since lichen is a symbiotic association between an alga and a fungi, which live together for their mutual benefit. The fungus holds water, provides protection and ideal housing to the alga.
The alga in turn supplies carbohydrate food for the fungus. If the alga is capable of fixing nitrogen (e.g. Nostoc), it supplies fixed nitrogen to the fungus. The kind of mutual interdependence helps lichens to grow on dry, barren rocks, where the other plants fail to exist. Morever, the algae or the fungi alone cannot grow in such places. Thus, both the partners cannot survive without each other.

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