Plus One Biology (Bot + Zoo) | Practice Model Question Paper PDF with Answer key | SET 8

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PART A: BOTANY

I. Answer any 3 questions from 1 – 5. Each carries 1 score. (3 x 1 = 3)

1) The parenchymatous cells which lie between the xylem and the phloem are called ……………….

✅ Conjunctive tissue

2) Vacuole is bound by a single membrane called ……………….

✅ Tonoplast

3) Observe the given stage of mitosis. Identify it.

✅ Telophase

4) The reaction center of photosystems in green plants during light reaction is ................

a) Xanthophyll        b) Carotenoids

c) Chlorophyll b        d) Chlorophyll a

✅ Chlorophyll a

5) The complete oxidation of pyruvic acid yields three molecules of CO2 by a cyclic process in the matrix of mitochondria. Who first developed this cycle?

✅ Hans Krebs

II. Answer any 9 questions from 6 – 16. Each carries 2 scores. (9 x 2 = 18)

6) Observe the figure given below. Name the organism. Mention its any two features.

Answer

Euglena.

Features:

• Instead of a cell wall, they have a protein rich layer called pellicle. It makes their body flexible.

• They have two flagella, a short and a long one.

7) Write any two distinguishing features of the algal class Rhodophyceae.

Answer

• Flagella are not present in gamete and spores.

• Red pigment r-phycoerythrin is present.

• Stored food-Foridean starch is present.

8) Distinguish between mycorrhiza and coralloid roots.

Answer

• Mycorrhiza: It is the symbiotic association of algae and fungi.

• Coralloid root: It is theassociation of fungus with root.

9) (a) What is respiratory climactic?

(b) ………………. were discovered as kinetin from the autoclaved herring sperm DNA.

Answer

(a) In plants, Ethylene promotes fruit ripening. It enhances respiration rate during fruit ripening. This is called respiratory climactic.

(b) Cytokinins

10) “Respiration is an amphibolic pathway.” Evaluate the statement.

Answer

In amphibolic pathway, both catabolism and anabolism are involved.

In respiratory pathway, fat is breakdown into fatty acid and glycerol, fatty acid again splits into acetyl coA. If body require the synthesis of fat, acetyl coA withdraws from pathway and used in the synthesis of fat.

11) Fermentation is the incomplete oxidation of pyruvic acid. Find the difference between two types of fermentations in microorganisms.

Answer

In alcoholic fermentation, glucose undergoes incomplete oxidation in the presence of yeast and forms ethyl alcohol and CO2.

In lactic acid fermentation, glucose undergoes incomplete oxidation in the presence of lactobacillus and forms lactic acid.

12) a) Identify the odd one from the given list of plant growth regulators.

i) ABA

ii) NAA

iii) IAA

iv) IBA

b) List some physiological responses of gibberellins in plants.

Answer

a) ABA

b) 1) GA3 increases the length of grapes stalks.

2) Gibberellins elongate and improve the shape of fruits like apple.

3) They delay senescence.

4) GA3 is used to speed up the malting process in brewing industry.

13) Given below is a floral formula of mustard family Brassicaceae. What does each symbol represent? Write any 4.

⊕⚥K2+2 C4 A2+4 G(2)

Answer

⊕ - Actinomorphic

⚥ - Bisexual

K - Calyx

C - Corolla

A - Androecium

G - Gynoecium

14) Pigments are substances that can absorb light at specific wavelengths. In plants, Chlorophyll a is the chief pigment present in leaf.

a) Name the accessory pigments in plant leaves.

b) Mention any one function of accessory pigments.

Answer

(a) Chlorophyll b, Xanthophylls and Carotenoids.

(b) Functions of accessory pigments:

o They absorb light at different wavelength and transfer the energy to chlorophyll a.

o They protect chlorophyll a from photo-oxidation.

15) Match the column A with column B.

Answer

16) Define placentation. Identify the following types of placentation A and B.

Answer

Placentation is the arrangement of ovules on the placenta within the ovary.

A= Parietal

B= Free central

III. Answer any 3 questions from 17 – 20. Each carries 3 scores. (3 x 3 = 9)

17) a) Name the special type of leaf anatomy shown by C4 plants.

b) Illustrate the major advantages of C4 plants over C3 plants.

Answer

a) Kranz anatomy.

b) C4 plants are photosynthetically efficient than C3 plants because energy wasteful process photorespiration occurs in C3.

C4 plants can tolerate high temperature conditions than C3 plants.

18) a) identify the substages of meiosis in which crossing over is occurring.

i) Leptotene

ii) Zygotene

iii) Pachytene

iv) Diplotene

b) Summarize the significance of meiosis in sexually reproducing organisms.

Answer

a) Pachytene

b) 1) Meiosis conserves the specific chromosome number of each species across generations in sexually reproducing organisms.

2) It results in reduction of chromosome number by half.

3) It increases the genetic variability from one generation to the next.

4) Variations are very important for the process of evolution.

19) Observe the given diagram. Analyze this diagram and explain the structure of plasma membrane.

Answer

Fluid mosaic model of cell membrane:

According to this, the quasi-fluid nature of lipid enables lateral movement of proteins within the overall bilayer. It consists of lipid bilayer. They are arranged within the membrane with the polar head towards the outer sides and the hydrophobic tails towards the inner part. The peripheral proteins lie on the surface of membrane while the integral proteins are buried in the membrane.

20) In the anatomy lab, Sajan observed the following features in the T.S. of a plant part.

i) Radial and polyarch xylem bundles

ii) Parenchymatous (homogenous) cortex

iii) Large pith

iv) Epidermis with epidermal hairs

v) Pericycle

vi) Endodermis with casparian strips

a) Identify the T.S.

b) Re-arrange the given regions from the periphery to the centre in their correct sequence.

c) Give an account of casparian strips.

Answer

a) Monocot root

b)

iv) Epidermis with epidermal hairs

ii) Parenchymatous (homogenous) cortex

vi) Endodermis with casparian strips

v) Pericycle

i) Radial and polyarch xylem bundles

iii) Large pith

c) The tangential and radial walls of the endodermal cells of roots have a deposition of water-impermeable, waxy material suberin in the form of casparian strips.

PART B: ZOOLOGY

I. Answer any 3 questions from 1 – 5. Each carries 1 score. (3 x 1 = 3)

1) Note the relationship in the first pair and complete the second pair.

a) Insulin: Hypoglycemic hormone

.....................: Hyperglycemic hormone.

b) Over secretion of Growth hormone: Gigantism

Low secretion of Growth hormone: ……………….

✅ (a) Glucagon (b) Dwarfism

2) Name a phospholipid found in cell membranes.

✅ Lecithin

3) Complete the following sentence:

Hilum leads to funnel shaped cavity called ………………. with projections called calyces.

✅ Renal pelvis

4) Which of the following is not come under the genus Panthera?

(a) Cat        (b) Lion

(c) Leopard        (d) Tiger

✅ (a) Cat

5) Name an instrument used to estimate the volume of air involved in breathing movements.

✅ Spirometer

II. Answer any 9 questions from 6 – 16. Each carries 2 scores. (9 x 2 = 18)

6) Name the phyla in which the following cells/ structures/ organs are present.

a) Radula        b) Cnidoblast

c) Pneumatic bone        d) Proboscis gland

Answer

a) Mollusca

b) Cnidaria

c) Chordata – Aves

d) Hemichordata

7) Metabolites are organic compounds constantly utilized in various metabolic activities in the cells.

a) What are the two types of metabolites in cells?

b) Give an example for each type of metabolites.

Answer

a) Primary metabolites & secondary metabolites.

b) Primary metabolites: Amino acids, protein, carbohydrate etc.

Secondary metabolites: Alkaloids, terpenoids etc.

8) The characteristic features of an invertebrate are given.

“The phylum includes the comb jellies, also called walnuts. They are noted for their bioluminescence and comb plates.”

a) Identify the phylum.

b) What is meant by bioluminescence?

c) What is the function of comb plates?

Answer

(a) Ctenophora

(b) Bioluminescence is the ability of organisms to emit light from the body.

(c) Locomotion.

9) Observe the diagram of reproductive system of male frog. Label A to D.

Answer

A= Vasa efferentia

B= Testis

C= Urinogenital duct

D= Cloaca

10) “Sinoatrial Node is called pace maker of our heart.”

a) Justify the statement.

b) Define cardiac cycle and cardiac output.

Answer

a) SA node initiates, regulate and maintains heart beat.

b) Cardiac cycle: Sequence of events during the completion of one heart beat (systole and diastole).

Cardiac output: Volume of blood pumped by each ventricle per minute.

11) Match the following:

Answer

12) “A contracted muscle becomes shorter and thicker but its volume remains the same.”

a) Which theory explains the process of muscle contraction?

b) Identify two contractile proteins seen in muscle.

Answer

a) Sliding filament theory.

b) Actin and Myosin.

13) Phylum Chordata is classified into three subphyla such as Urochordata, Cephalochordata and Vertebrata. They all have notochord but shows some differences. Compare the notochord of Urochordata and Cephalochordata.

Answer

In Urochordata, notochord is present only in larval tail.

In Cephalochordata, it extends from head to tail region and is persistent throughout their life.

14) Observe the given Sigmoid curve on the graph and answer the following questions.

a) Find out the pO2 at which 90% saturation of haemoglobin with oxygen occurs.

b) Write any three factors that favours dissociation of Oxyhaemoglobin.

Answer

a) 60 mmHg

b) low pO2, high pCO2, high H+ ions, high temperature.

15) Enzymes are biocatalysts which regulate various biochemical reactions. Illustrate the following reactions.

E+S → ES → EP → E+P

Answer

• The substrate binds to the active site of enzyme (E+S).

• The substrate is tightly bound with active site of enzyme to form enzyme- substrate complex (ES).

• The active site breaks chemical bonds of substrate to form enzyme- product complex (EP).

• The enzyme releases the products (E+P).

16) Like insulin and glucagon, PTH and calcitonin are antagonistic in their action in maintaining normal blood calcium level. Substantiate this statement.

Answer

Insulin decreases blood glucose level (hypoglycemic hormone) and Glucagon increases blood glucose level (hyperglycemic hormone).

Likewise, PTH increases Ca2+ level in blood (hypercalcaemic hormone). Calcitonin decreases Ca2+ level in blood (hypocalcaemic hormone).

Thus PTH and TCT are antagonistic in action.

III. Answer any 3 questions from 17 – 20. Each carries 3 scores. (3 x 3 = 9)

17) Observe the diagram and construct a flow chart to show the mechanism of transmission of nerve impulse across a chemical synapse.

Answer

Impulse reaches at axon terminal → synaptic vesicles bind on plasma membrane → release of neurotransmitter → It diffuses across synaptic cleft → combine with receptors on the post synaptic membrane → opening of ion channels allowing entry of ions → generates action potential.
18) Match the items in columns B and C with A.

Answer

19) “The functioning of human kidney is efficiently monitored and regulated by hormonal actions of hypothalamus pituitary, JGA and to a certain extent by heart."

a) Do you agree with this statement?

b) Justify your answer with suitable reasons.

Answer

a) Yes.

b) ADH is produced by hypothalamus. It regulates the kidney function by constricting blood vessels and helping in water reabsorption.

JGA is found in the distal convoluted tubule. A fall in GFR activate the JG cells to release renin which stimulate the glomerular blood flow.

ANF is found atrial wall of heart. It causes vasodilation (dilation of blood vessels) and thereby decrease the blood pressure.

20) Draw a flowchart showing double circulation in human circulatory system.

Answer

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