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Principles of Inheritance and Variation — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYPrinciples of Inheritance and Variation4 Marks
Question
What is meant by chromosomal mutation?
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Answer

A change in the structure and/ or number of chromosomes in an organism, is called chromosomal mutation.

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Read the following and answer any four questions from (i) to (v) given below.
Prashant wanted to find the genotype of a pea plant bearing purple coloured flowers in his kitchen garden. For this, he crossed purple flowered plant with white flowered plant. As a result, all plants which were produced had purple flower only. Upon selfing these plants, 75 purple flower plants and 25 white flower plants were produced. Now, he can determine the genotype of a purple flowered plant by crossing it with a white flowered plant.
  1. Which of the following cannot be derived from the crosses done by Prashant?
  1. Mendel's law of segregation.
  2. Mendel's law of dominance.
  3. Mendel's law of independent assortment.
  4. Both (a) and (c).
  1. To determine the genotype of a purple flowered plant, Prashant crossed this plant with a white flowered plant. This cross represents a?
  1. Test cross.
  2. Dihybrid cross.
  3. Reciprocal cross.
  4. Trihybrid cross.
  1. In white flowered plant, allele is expressed in?
  1. Heterozygous condition only.
  2. Homozygous condition only.
  3. F3 generation.
  4. Both homozygous and heterozygous condition.
  1. The character, i.e., purple colour of the flowers that appeared in the first filial generation is called?
  1. Recessive character.
  2. Dominant character.
  3. Dominant character.
  4. Lethal character.
  1. Assertion: A geneticist crossed two plants and he obtained 50% purple flowered plants and 50% white flowered plants.
Reasons: Purple coloured flower plant might be heterozygous.
  1. Both assertion and reason are true and reason is the correct explanation of assertion.
  2. Both assertion and reason are true but reason is not the correct explanation of assertion.
  3. Assertion is true but reason is false.
  4. Both assertion and reason are false.
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Read the following and answer any four questions from (i) to (v) given below:
A functional mammary gland is characteristic of all female mammals. Mammary glands are paired structures that contain glandular tissue and variable amount of fat. Refer to the given figure of a mammary gland and answer the following questions.
  1. Mammary glands are modified:
  1. Sweat glands.
  2. Sebaceous glands.
  3. Sudoriferous glands.
  4. Lacrimal glands.
  1. Identify the incorrectly matched pair.
  1. P - Areola.
  2. Q - Lactiferous duct.
  3. S - Mammary duct.
  4. T - Mammary alveoli.
  1. Mammary ducts expand to form:
  1. Mammary alveoli.
  2. Mammary ampullae.
  3. Lactiferous ducts.
  4. Mammary tubules.
  1. What is areola?
  1. Grape-like clusters of milk secreting structures.
  2. Fatty tissue between the mammary lobes.
  3. Circular pigmented area of skin around nipple.
  4. Connective tissue that supports the alveoli and ducts.
  1. Assertion: The size of breast depends on the amount of adipose tissue.
Reason: The adipose tissue supports the alveoli and the ducts.
  1. Both assertion and reason are true, and reason is the correct explanation of assertion.
  2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
  3. Assertion is true, but reason is false.
  4. Both assertion and reason are false.
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Callus culture and Suspension culture.
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DiseaseSymptoms
(1) Asthma(a) Fully blown out alveoli
(2) Bronchitis(b) Inflammation of lungs with cough and fever
(3) Emphysema(c) Spasm of Bronchial muscles
(4) Pneumonia(d) Inflammation of bronchi
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Read the following and answer any four questions from (i) to (v) given below:
Ananya is a biologist, her research guide assigned project, i.e., to determine the effect ofin tra-specific competition on the growth of sapling of Eucalyptus. For this, she designed an experiment in which two sets of pots were used. ln the first set (set A) only I sapling was planted per pot and in the other set (set B) $16$ saplings were planted per pot. To check for the effect of intra-specific competition on allocation of resources, a decreasing amount of water was added to each set. The results have been graphically indicated. Which of the following conclusions can indicated as follows:
  1. Which of the following statements can be concluded from the given study?
  1. More resources are allocated to the root during low water conditions.
  2. Competition for water among individuals of a population causes more root growth as compared to individuals who are growing alone.
  3. Lesser leaves are formed under low water conditions.
  4. Root growth is higher in individual grown singly as compared to individuals in populations.
  1. Which of the following associations is an example of competitions?
  1. Cuscuta and hedge plant.
  2. Balanus and Cathamalus.
  3. Cactus and moth.
  4. Orchid and mango.
  1. If '+' sign is assigned to beneficial interaction, '-' sign to detrimental and O sign to neutral interaction, then the population interaction of competition refers to:
  1. +, +
  2. -, -
  3. +, -
  4. +, 0
  1. lntraspecific competition is more severe due to:
  1. similar needs.
  2. similar adaptations.
  3. common resources.
  4. all of these.
  1. Assertion: Two members of a competing species may co-exist.
Reason: Different individuals of a species have different resource requirements.
  1. Both assertion and reason are true and reason is the correct explanation of assertion.
  2. Both assertion and reason are true but reason is not the correct explanation of assertion.
  3. Assertion is true but reason is false.
  4. Both assertion and reason are false.
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Old or classical biotechnology and Modem biotechnology.
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Read the following and answer any four questions from (i) to (v) given below:
A young couple married for 5 years is unable to bear a child in spite of not practicing any birth control method. Upon consultation, doctor advised them an assisted reproductive technology involving transfer of gametes into oviducts.
  1. Identify the technique adopted by the couple.
  1. ZIFT
  2. JUI
  3. GIFT
  4. ICSI
  1. What is the pre-requisite of this technique?
  1. Gamete formation should be normal.
  2. Fallopian tubes should be normal.
  3. Female should have thick endometrial lining.
  4. Male should be able to copulate the female.
  1. Assertion: GIFT is an in-vitro fertilisation technique.
Reason: In GIFT, gametes are fertilised outside the female body.
  1. Both assertion and reason are true, and reason is the correct explanation of assertion.
  2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
  3. Assertion is true, but reason is false.
  4. Both assertion and reason are false.
  1. The procedure advised to couple involves the transfer of:
  1. Fertilised ovum.
  2. Embryo with 8 blastomeres.
  3. Sperms and unfertilised ovum.
  4. Embryo with 16 blastomeres.
  1. What is the success rate of this procedure?
  1. 30-50%
  2. < 20%
  3. 80-85%
  4. 27-30%
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Distinguish between : Cerebrum and cerebellum
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Column I [Phases]Column II [Hormonal changes]
(1) Menstrual phase(a) Rapid secretion of LH
(2) Proliferative phase(b) Increased level of FSH and estrogen
(3) Ovulatory phase(c) Increased level of progesterone
(4) Secretory phase(d) Decrease in progesterone and estrogen
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Read the following and answer any four questions from (i) to (v) given below: Within a region, species richness increases with increasing explored area, but only upto a limit. TI1e given graph explains this relationship.
  1. What does the given figure show?
  1. Rivet-popper hypothesis.
  2. Species-area relationship.
  3. Proportionate number of species of major taxa.
  4. $\alpha-\text{ecological diversity }$
  1. Equation for relationship (A) between species richness and area is:
  1. $\log\text{ S}=\log\text{ C}+\text{Z }\log\text{ A}$
  2. $\log\text{ C}=\log\text{ S}+\text{Z }\log\text{ A}$
  3. $\text{Z }\log\text{ A}=\log\text{ S}+\log\text{ C}$
  4. $\log\text{ S}=\log\text{ C}+\log\text{ A}$
  1. What is the value of slope of line or regression coefficient Z for frugivorous birds?
  1. 0.1 - 0.2
  2. 1.15
  3. 0.01 - 0.1
  4. 0.6 - 1.2
  1. The shape of curve for relationship between species richness and areas for wide variety of taxa is:
  1. Straight line.
  2. Parabola.
  3. Rectangular hyperbola.
  4. Bell shaped.
  1. Who gave this concept of increase in species richness with increasing offered area?
  1. Humboldt.
  2. Odum.
  3. Edward Wilson.
  4. Paul Ehrlich.
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