Maharashtra Board Class 12 Biology 2023 Exam

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Questions and Answers

Histones are rich in

Lysine and Arginine (correct)
Leucine and Methionine
Phenyl alanine and Lysine
Serine and Leucine

How many mitotic divisions take place during the formation of a female gametophyte from a functional megaspore?

Two
Four (correct)
One
Three

Which of the following is the only gaseous plant growth regulator?

Cytokinin
Gibberellin
Ethylene (correct)
ABA

The pH of nutrient medium for plant tissue culture is in the range of

7 to 7.5 (D) Signup and view all the answers

Rivet Popper Hypothesis is an analogy to explain the significance of

Biodiversity (B) Signup and view all the answers

Which of the following group shows ZW-ZZ type of sex determination?

Parrot, Bat, Fowl (A) Signup and view all the answers

In Hamburger's phenomenon,

Cl- diffuse into RBCs (D) Signup and view all the answers

Calcium and Phosphate ions are balanced between blood and other tissues by

Calcitonin and Thymosin (B) Signup and view all the answers

Identify the INCORRECT statement.

Water potential of pure water is negative (C) Signup and view all the answers

Which of the following is a hormone releasing contraceptive?

LNG-20 (B) Signup and view all the answers

Which disease is caused by HPV?

Cervical cancer Signup and view all the answers

Which device is used to clean both dust and gases from polluted air?

Electrostatic precipitator Signup and view all the answers

Mention the name of sterile animal produced by intergeneric hybridisation.

Mule Signup and view all the answers

Give the name of the first transgenic plant.

Flavr Savr tomato Signup and view all the answers

A child has low BMR, delayed puberty and mental retardation. Identify the disease.

Cretinism Signup and view all the answers

Identify 'A' in the given graph of population growth.

Exponential growth phase Signup and view all the answers

_______________ Pre-mature fall of flowers, fruits and leaves

Abscission Signup and view all the answers

_______________ Appearance of green and non-green patches on leaves

Chlorosis Signup and view all the answers

Give an example of plant having both kidney and dumbbell shaped guard cells in stomata.

Onion Signup and view all the answers

Define the terms

a) Gross primary productivity, b) Net primary productivity Signup and view all the answers

Draw a neat diagram of thyroid gland and label thyroid follicle, follicular cells and blood capillaries.

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Give reason – ABA is also known as antitranspirant.

ABA inhibits stomatal opening, thus decreasing water loss through transpiration. It also promotes the closure of stomata in response to water stress. These actions help plants conserve water during periods of drought or stress. Signup and view all the answers

Explain the role of chlorophyllase enzyme in banana.

Chlorophyllase breaks down chlorophyll, the green pigment in plants, into colorless compounds. This breakdown is responsible for the yellowing of banana fruits that occurs during ripening. It is a key enzyme in the process of ripening, and it is also responsible for the characteristic changes in color and flavor that occur as bananas mature. Signup and view all the answers

Disorders/diseases Recombinant Proteins ____ Erythropoietin Asthma _ Tissue plasminogen activator Emphysema ______

Anemia, Anti-asthma drugs (e.g., interferon), Cystic fibrosis, Protease inhibitors Signup and view all the answers

Define -- Imbibition

Imbibition is the process of absorption of water by solid, hydrophilic materials like seeds and wood. It occurs due to the attraction between water molecules and the molecules of the solid material. Signup and view all the answers

Explain how imbibition helps root hairs in adsorption of water.

Imbibition in root hairs helps in the adsorption of water as it creates a negative pressure that draws water into the root. This occurs due to the hydrophilic properties of the root hair cell wall, which attracts water molecules and causes swelling. The swelling of the root hair cells increases their surface area and creates a gradient, allowing water to be drawn into the root hair. Signup and view all the answers

Draw a neat diagram of the conducting system of human heart and label AV node, Bundle of His and Purkinje fibres.

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Distinguish between heterochromatin and euchromatin with reference to staining property and activity.

Heterochromatin stains darkly, is tightly packed, and is inactive, while euchromatin stains lightly, is loosely packed, and is active in transcription. Signup and view all the answers

Ecosystem and re-write: _____ Herbivores Primary Producer _ _ Man, Lion Secondary consumer _____

Decomposers, Plants, Carnivores, Omnivores Signup and view all the answers

What is biofortification?

Biofortification is the process of increasing the nutritional value of crops by breeding them to contain more nutrients. This is a sustainable and cost-effective way to address malnutrition and improve public health. Signup and view all the answers

Mention one example each of fortification with reference to (i) Amino acid content (ii) Vitamin-C content

<ol> <li>Amino acid content - Fortified cereals with lysine (e.g., wheat, rice); Vitamin C content - Fortified orange juice.</li> </ol> Signup and view all the answers

Differentiate between X-chromosome and Y-chromosome with reference to (a) length of non-homologous regions (b) type as per position of centromere.

<ol> <li>The X-chromosome is larger and has a longer non-homologous region than the Y-chromosome. The Y-chromosome is smaller and has a shorter non-homologous region than the X-chromosome.</li> <li>The X-chromosome is submetacentric, meaning that the centromere is located near the center of the chromosome. The Y-chromosome is acrocentric, meaning that the centromere is located near one end of the chromosome.</li> </ol> Signup and view all the answers

Flashcards

HSC

The Maharashtra Board conducts the HSC examination, which is the equivalent of the 12th grade board exam in India.

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HSC Question Paper

The Maharashtra Board's HSC question paper is available online through AglaSem.

Study Notes

Maharashtra Board Class 12 Biology Question Paper 2023

The exam is 3 hours long.
The paper has 8 pages.
Maximum marks are 70.
The question paper is divided into four sections.
Section A has 10 multiple choice questions (MCQs). Each carries one mark. Students must write the correct answer (e.g., (a)) with the answer choice.
Section B has 8 very short answer questions, carrying one mark each.
Section C includes questions 3-14, each carrying two marks. Students must answer any eight.
Section D has questions 15-26, each carrying three marks. Students must answer any eight.
Section D has questions 27-31. Each question carries four marks. Students must answer any three.
Each section's answers should be on new pages.

Section A - Multiple Choice Questions

Histones are rich in Lysine and Arginine.
Mitotic divisions for female gametophyte formation from a megaspore are two.
ABA is a gaseous plant growth regulator.
Plant tissue culture pH range is 5.5 to 5.8.
Rivet Popper Hypothesis relates to biodiversity.
ZW-ZZ sex determination in Pigeon, Parrot, Sparrow, Bat, Fowl, Crow, Sparrow, Fowl, and Cat.
Cl diffuse into RBCs in Hamburger's phenomenon.
Calcium and Phosphate ions balanced by Calcitonin and Thymosin.
In a flaccid cell, turgor pressure (TP) is zero.
A hormone releasing contraceptive is Cu-T.

Section B - Very Short Answer Questions

Questions 3 to 14 require short answers. Each carries 2 marks.
Students must answer any 8 questions.

Section C - Short Answer Questions

Questions 15 to 26 require short answers. Each question carries 3 marks.
Students must answer any 8 questions.

Section D - Long Answer Questions

Questions 27 to 31 require detailed answers. Each question carries 4 marks.
Students must answer any three questions.

General Instructions

The exam paper is divided into four sections.
Multiple choice answers require the correct answer choice letter(s).
Short and long answer questions should be attempted as per the directions in the question paper.

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Description

Prepare for the Maharashtra Board Class 12 Biology examination with this comprehensive question paper for 2023. It includes multiple sections covering a variety of topics, ranging from multiple choice questions to detailed answers. Test your knowledge and readiness for the exam with this structured format.