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

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👉 Download Biology Question Paper PDF - SET 6

PART A: BOTANY

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

01) In the family Solanaceae, stamens are described as ........

a) Five, epipetalous
b) Ten, diadelphous
c) Six, epipetalous
d) Six, diadelphous

✅ a) Five, epipetalous

02) Identify the kingdom based on the clues given below.

Eukaryotic organisms, their cell wall is made up of chitin.

✅ Kingdom Fungi

03) In most woody trees, epidermis breaks to form a lens shaped opening. Name this opening that permits gaseous exchange.

✅ Lenticels

04) An enzyme present in plants shows carboxylation and oxygenation activity. Identify the enzyme.

✅ RUBISCO

05) Internode elongation just prior to flowering is called ……………….

✅ Bolting

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

06) Name the following:

a) Viruses that attack bacteria.
b) The bacteria that live in extreme salty areas.
c) The smallest known living cells.
d) The aggregation formed by slime moulds under suitable condition.

✅ Answer

(a) Bacteriophage (b) Halophiles

07) Distinguish between protonema and prothallus.

✅ Answer

Protonema: It is a creeping, green, filamentous branched structure developing directly from a spore of moss/bryophyte. First gametophytic stage.

Prothallus: Photosynthetic gametophyte of pteridophytes.

08) Give the scientiﬁc term of the following.

a) Interchange of genetic material between non-sister chromatids of homologous chromosomes.

b) The complex formed by a pair of synapsed homologous chromosomes.

✅ Answer

a) Crossing over

b) Bivalent or a tetrad

09) Stomata are small openings present in the epidermis of leaves. Name the cells which bound the stomata. Mention their role in stomatal mechanisms.

✅ Answer

Guard cells. They regulate the opening and closing of stomata.

10) The following are the characters of dicot stem and monocot stem. Identify the characters and write in appropriate column.

a) Sclerenchymatous hypodermis
b) Collenchymatous hypodermis
c) Vascular bundles are conjoint, closed
d) Vascular bundles are arranged in a ring.

✅ Answer

11) "Meiosis is highly significant in sexually reproducing organisms". Justify.

✅ Answer

It ensures the conservation of specific chromosome number.

It creates genetic variation.

12) ‘Photorespiration is a curse to plants.’ Evaluate this statement.

✅ Answer

In photorespiration, there is no synthesis of sugars, ATP and NADPH. Rather it causes the release of CO2 by using ATP. It decreases the efficiency of photosynthesis.

13) Observe the given figure. Identify this and label A and B.

✅ Answer

It represents ATP synthesis through chemiosmosis.

A= P680 PS II
B= P700 PS I

14) The following is a list of cell organelles:

(Nucleus, endoplasmic reticulum, lysosomes, chloroplast, Golgi complex, mitochondria, ribosome)

a) Identify the organelles with double membrane envelope.

b) Mention the functions of any one of these organelles.

✅ Answer

(a) Nucleus, Mitochondria and Chloroplast.

(b) Function of Mitochondria: These are the sites of aerobic respiration. They produce energy in the form of ATP. So they are called ‘power houses’ of the cell.

15) What are the two crucial events of aerobic respiration?

✅ Answer

(a) Complete oxidation of pyruvate by stepwise removal of all the hydrogen atoms, leaving 3 CO2 molecules. It takes place in the matrix of mitochondria.

(b) Passing on of electrons removed as part of H-atoms to molecular O2 with simultaneous synthesis of ATP. It occurs on the inner membrane of mitochondria.

16) The figure showing the pathway of Tricarboxylic acid cycle is given below. Name the compound present in the position of A, B, C, D.

✅ Answer

A= Citric acid (TCA)
B= α-ketoglutaric acid
C= Malic acid
D= Oxaloacetic acid (OAA)

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

17) Observe the diagrams given below.

(a) Name the type of ﬂowers A and B. Give one example of each.
(b) Write two differences between racemose and Cymose inﬂorescence.

✅ Answer

(a) A= Hypogynous flower. E.g. mustard, China rose etc.

B= Epigynous flower. E.g. guava, cucumber etc.

(b) Racemose: Main axis grows continuously. Flowers are borne in an acropetal order.

Cymose: Main axis terminate in a flower. Flowers are borne in a basipetal order.

18) (a) Ethylene is a gaseous hormone. Describe its any five different actions in plants.

(b) Name the most widely used source of ethylene.

✅ Answer

(a) Actions of ethylene in plants:

• Promotes senescence and abscission of plant organs.
• Promotes fruit ripening.
• Breaks seed and bud dormancy.
• Promotes rapid internode/petiole elongation in deep water rice plants.
• Promotes root growth and root hair formation.

(b) Ethephon

19) Position of centromere determine the shape of the chromosomes.

a) Name the different types of chromosomes based on the position of centromere.
b) Draw any one chromosome among them.

✅ Answer

a) Metacentric, Submetacentric, Acrocentric & Telocentric.

b) Figure (any one):

20) Photophosphorylation takes place during photosynthesis.

a) Name the types of photophosphorylation.
b) Distinguish between them. (Hint: Any two differences)

✅ Answer

Cyclic photo-phosphorylation & Non-cyclic photo-phosphorylation.

Cyclic photo-phosphorylation:

▪️ It occurs in stroma lamellae when only PS I is functional.

▪️ The electron is circulated within the photosystem and the ATP synthesis occurs due to cyclic flow of electrons.

▪️ Here, only ATP is synthesised (no NADPH + H+).

Non-cyclic photo-phosphorylation:

▪️ It occurs when the two photosystems work in a series, (first PS II and then PS I) through an electron transport chain as seen in the Z scheme.

▪️ Here, ATP & NADPH + H+ are synthesised.

PART B: ZOOLOGY

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

01) Analyze the following scientific name. If there any mistake, correct it.

mangifera Indica

✅ Mangifera indica

02) The diagram of an animal is given. Identify its symmetry.

✅ Bilateral symmetry

03) Identify the WRONG statement from the following and correct it.

a) Lipids are not strictly macromolecules.
b) Cellulose is not a polysaccharide.

✅ (b) is wrong statement. Cellulose is a polysaccharide.

04) In a muscle fibre, Actin contains 2 other proteins namely ………………. and ……………….

✅ Tropomyosin & troponin

05) Lungs are situated in thoracic chamber and rest on ……………….

✅ Diaphragm

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

06) Two characters of an invertebrate animal is given:

• Jointed appendages

• Malpighian tubules

Identify the phylum and write role of Malpighian tubules in it.

✅ Answer

Phylum Arthropoda.

Role of Malpighian tubules: Excretory organ.

07) Match the column A column B.

✅ Answer

08) Name the following:

a) The amino acid structure in which both –NH2 & –COOH are ionized.
b) The compound formed of a nitrogen base, a sugar and a phosphate group.
c) A protein that enables glucose transport into cell.
d) The bond between amino acids in a protein.

✅ Answer

a) Zwitterion b) Nucleotide

c) GLUT-4 d) Peptide bond

09) (a) Examples of two enzymatic reactions A and B are given. Identify the class of enzymes in A and B.

A) S Reduced + S' Oxidized → S Oxidized + S' Reduced
B) S – G + S' → S+S'G

(b) "Protein is a heteropolymer not a homopolymer”. Substantiate the statement.

✅ Answer

9. (a)

(A) Oxido-reductases.
(B) Transferases.

(b) Proteins are made up different types of amino acid monomers. So they are heteropolymers.

10) In the given graph of oxygen-haemoglobin dissociation curve ‘X’ axis denote partial pressure of oxygen. What does 'Y' axis indicate? Write any two factors which affect the sigmoid curve.

✅ Answer

Y axis indicates percentage saturation of haemoglobin with oxygen.

Factors which affect the sigmoid curve: pCO2, pO2, H+ concentration etc.

11) Draw a flowchart showing the correct sequence of various parts of frog’s alimentary canal.

✅ Answer

Mouth → buccal cavity → pharynx → oesophagus → stomach → intestine → rectum → cloaca.

12) SA node has the key role in the rhythmic contractile activity of human heart. Give a reason.

✅ Answer

SA node initiates and maintains contraction of heart by generating action potentials. i.e., it acts as pacemaker.

13) (a) In the medical record of a patient, blood pressure is noted as 170/130 mmHg. What does this condition indicate?

(b) How will this affect the body?

✅ Answer

a) He has hypertension (high blood pressure).

b) It leads to heart diseases and affects vital organs (brain, kidney etc).

14) Observe the given diagram of Malpighian body (renal corpuscle) and answer the following.

a) Identify the parts A and B.

b) Specify the function of proximal convoluted tubule in urine formation.

✅ Answer

a) A = Afferent arteriole

B= Bowman’s capsule.

b) PCT reabsorbs most of the nutrients, and 70-80% of electrolytes & water. Cells of PCT & DCT maintain ionic and pH of body fluids by selective secretion of H+, K+ & NH3 into the filtrate and absorption of HCO3- from it.

15) An athlete met an accident on the ground. His thigh bone slipped off from the girdle.

a) Write the name of the above-mentioned girdle.

b) Identify the type of joint that slipped off.

c) Name the disorder caused due to the accumulation of uric acid crystals in such a joint.

✅ Answer

a) Pelvic girdle.

b) Ball and socket joint.

c) Gout.

16) a) Name the 3 processes of urine formation.

b) What is the normal value of GFR?

✅ Answer

a) Glomerular filtration, reabsorption & secretion.

b) 125 ml/minute, i.e., 180 litres/day.

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

17) Nerve impulse transmission include generation and propagation of action potential. Write various stages or events in the generation of action potential.

✅ Answer

• In a resting neuron, axoplasm has high K+ and negatively charged proteins, while Na+ is low. The outer membrane has low K+ and high Na+, creating an ionic gradient.

• Na-K pump maintains the gradient by actively transporting ions (3 Na+ out, 2 K+ in). Thus outer surface becomes positively charged and inner surface negatively charged. This is called resting potential.

• Upon stimulus, the membrane at site A becomes permeable to Na+, leading to depolarization and the generation of an action potential.

• Ahead at site B, the outer surface is positive, and the inner surface is negative, causing a current flow from A to B. On the outer surface, a current flows from B to A to complete the circuit. It generates an action potential at site B.

18) The table shown below is a reference chart based on blood group compatibility. Complete the chart.

✅ Answer

(i) AB (ii) A

(iii) AB (iv) O

(v) AB (vi) O

19) Observe the following branching tree diagram.

a) Complete the representation by ﬁlling ‘X’ and ‘Y’.

b) Adrenal medullary hormones are called ‘Hormones of fight or ﬂight.’ Why?

✅ Answer

a) X= Adrenal cortex.

Y= Noradrenalin

b) They are rapidly secreted in response to stress emergency situations and increase alertness, pupillary dilation, sweating, heartbeat and respiratory rate. So these hormones are called hormones of Fight or Flight.

20) Observe the following vertebrate classification.