Plus One / 12th Bio-Botany - Book Back Answers - Chapter 2 - English Medium
Tamil Nadu Board 12th Standard Bio-Botany - Chapter 2: Book Back Answers and Solutions
This post covers the book back answers and solutions for Chapter 2 – Bio-Botany from the Tamil Nadu State Board 12th Standard Bio-Botany textbook. These detailed answers have been carefully prepared by our expert teachers at KalviTips.com.
We have explained each answer in a simple, easy-to-understand format, highlighting important points step by step under the relevant subtopics. Students are advised to read and memorize these subtopics thoroughly. Once you understand the main concepts, you’ll be able to connect other related points with real-life examples and confidently present them in your tests and exams.
By going through this material, you’ll gain a strong understanding of Bio-Botany Chapter 2 along with the corresponding book back questions and answers (PDF format).
Question Types Covered:
- 1 Mark Questions: Choose the correct answer, Fill in the blanks, Identify the correct statement, Match the following
- 2 Mark Questions: Answer briefly
- 3, 4, and 5 Mark Questions: Answer in detail
All answers are presented in a clear and student-friendly manner, focusing on key points to help you score full marks.
All the best, Class 12 students! Prepare well and aim for top scores. Thank you!
I. Multiple Choice Questions
1. Extra nuclear inheritance is a consequence of presence of genes in
a) Mitochondria and chloroplasts
b) Endoplasmic reticulum and mitochondria
c) Ribosomes and chloroplast
d) Lysososmes and ribosomes
Answer Key:
a) Mitochondria and chloroplasts
2. In order to find out the different types of gametes produced by a pea plant having the genotype AaBb, it should be crossed to a plant with the genotype
a) aaBB
b) AaBB
c) AABB
d) aabb
Answer Key:
d) aabb
3. How many different kinds of gametes will be produced by a plant having the genotype AABbCC?
a) Three
b) Four
c) Nine
d) Two
Answer Key:
d) Two
4. Which one of the following is an example of polygenic inheritance?
a) Flower colour in Mirabilis jalapa
b) Production of male honey bee
c) Pod shape in garden pea
d) Skin Colour in humans
Answer Key:
d) Skin Colour in humans
5. In Mendel’s experiments with garden pea, round seed shape (RR) was dominant over wrinkled seeds (rr), yellow cotyledon (YY) was dominant over green cotyledon (yy). What are the expected phenotypes in the F2 generation of the cross RRYY x rryy?
a) Only round seeds with green cotyledons
b) Only wrinkled seeds with yellow cotyledons
c) Only wrinkled seeds with green cotyledons
d) Round seeds with yellow cotyledons and wrinkled seeds with yellow cotyledons
Answer Key:
d) Round seeds with yellow cotyledons and wrinkled seeds with yellow cotyledons
6. Test cross involves
a) Crossing between two genotypes with recessive trait
b) Crossing between two F1 hybrids
c) Crossing the F1 hybrid with a double recessive genotype
d) Crossing between two genotypes with dominant trait
Answer Key:
c) Crossing the F1 hybrid with a double recessive genotype
7. In pea plants, yellow seeds are dominant to green. If a heterozygous yellow seed pant is crossed with a green seeded plant, what ratio of yellow and green seeded plants would you expect in F1 generation?
a) 9:1
b) 1:3
b) 3:1
d) 50:50
Answer Key:
d) 50:50
8. Select the correct statement from the ones given below with respect to dihydrid cross
a) Tightly linked genes on the same chromosomes show very few combinations
b) Tightly linked genes on the same chromosomes show higher combinations
c) Genes far apart on the same chromosomes show very few recombinations
d) Genes loosely linked on the same chromosomes show similar recombinations as the tightly linked ones
Answer Key:
a) Tightly linked genes on the same chromosomes show very few combinations
9. Which Mendelian idea is depicted by a cross in which the F1 generation resembles both the parents
a) Incomplete dominance
b) Law of dominance
c) Inheritance of one gene
d) Co-dominance
Answer Key:
d) Co-dominance
10. Fruit colour in squash is an example of
a) Recessive epistatsis
b) Dominant epistasis
c) Complementary genes
d) Inhibitory genes
Answer Key:
b) Dominant epistasis
11. In his classic experiments on Pea plants, Mendel did not use
a)Flowering position
b) Seed colour
c) Pod length
d) Seed shape
Answer Key:
c) Pod length
12. The epistatic effect, in which the dihybrid cross 9:3:3:1 between AaBb x AaBb is modified as
a) Dominance of one allele on another allele of both loci
b) Interaction between two alleles of different loci
c) Dominance of one allele to another alleles of same loci
d) Interaction between two alleles of same loci
Answer Key:
b) Interaction between two alleles of different loci
c) Dominance of one allele to another alleles of same loci
13. In a test cross involving F1 dihybrid more parental type offspring were produced than the recombination type offspring. This indicates
a) The two genes are located on two different chromosomes
b) Chromosomes failed to separate during meiosis
c) The two genes are linked and present on the same chromosome
d) Both of the characters are controlled by more than one gene
Answer Key:
d) Both of the characters are controlled by more than one gene
14. The genes controlling the seven pea characters studied by Mendel are known to be located on how many different chromosomes?
a) Seven
b) Six
c) Five
d) Four
Answer Key:
c) Five
15. Which of the following explains how progeny can posses the combinations of traits that none of the parent possessed?
a) Law of segregation
b) Chromosome theory
c) Law of independent assortment
d) Polygenic inheritance
Answer Key:
c) Law of independent assortment
16. “Gametes are never hybrid”. This is a statement of
a) Law of dominance
b) Law of independent assortment
c) Law of segregation
d) Law of random fertilization
Answer Key:
c) Law of segregation
17. Gene which suppresses other genes activity but does not lie on the same locus is called as
a) Epistatic
b) Supplement only
c) Hypostatic
d) Codominant
Answer Key:
a) Epistatic
18. Pure tall plants are crossed with pure dwarf plants. In the F1 generation, all plants were tall. These tall plants of F1 generation were selfed and the ratio of tall to dwarf plants obtained was 3:1. This is called
a) Dominance
b) Inheritance
c) Codominance
d) Heredity
Answer Key:
a) Dominance
19. The dominant epistatis ratio is
a) 9:3:3:1
b) 12:3:1
c) 9:3:4
d) 9:6:1
Answer Key:
b) 12:3:1
20. Select the period for Mendel’s hybridization experiments
a) 1856 - 1863
b) 1850 - 1870
c) 1857 - 1869
d) 1870 - 1877
Answer Key:
b) 1850 - 1870
21. Among the following characters which one was not considered by Mendel in his experimentation pea?
a) Stem – Tall or dwarf
b) Trichomal glandular or non-glandular
c) Seed – Green or yellow
d) Pod – Inflated or constricted
Answer Key:
b) Trichomal glandular or non-glandular
a) Mitochondria and chloroplasts
b) Endoplasmic reticulum and mitochondria
c) Ribosomes and chloroplast
d) Lysososmes and ribosomes
Answer Key:
a) Mitochondria and chloroplasts
2. In order to find out the different types of gametes produced by a pea plant having the genotype AaBb, it should be crossed to a plant with the genotype
a) aaBB
b) AaBB
c) AABB
d) aabb
Answer Key:
d) aabb
3. How many different kinds of gametes will be produced by a plant having the genotype AABbCC?
a) Three
b) Four
c) Nine
d) Two
Answer Key:
d) Two
4. Which one of the following is an example of polygenic inheritance?
a) Flower colour in Mirabilis jalapa
b) Production of male honey bee
c) Pod shape in garden pea
d) Skin Colour in humans
Answer Key:
d) Skin Colour in humans
5. In Mendel’s experiments with garden pea, round seed shape (RR) was dominant over wrinkled seeds (rr), yellow cotyledon (YY) was dominant over green cotyledon (yy). What are the expected phenotypes in the F2 generation of the cross RRYY x rryy?
a) Only round seeds with green cotyledons
b) Only wrinkled seeds with yellow cotyledons
c) Only wrinkled seeds with green cotyledons
d) Round seeds with yellow cotyledons and wrinkled seeds with yellow cotyledons
Answer Key:
d) Round seeds with yellow cotyledons and wrinkled seeds with yellow cotyledons
6. Test cross involves
a) Crossing between two genotypes with recessive trait
b) Crossing between two F1 hybrids
c) Crossing the F1 hybrid with a double recessive genotype
d) Crossing between two genotypes with dominant trait
Answer Key:
c) Crossing the F1 hybrid with a double recessive genotype
7. In pea plants, yellow seeds are dominant to green. If a heterozygous yellow seed pant is crossed with a green seeded plant, what ratio of yellow and green seeded plants would you expect in F1 generation?
a) 9:1
b) 1:3
b) 3:1
d) 50:50
Answer Key:
d) 50:50
8. Select the correct statement from the ones given below with respect to dihydrid cross
a) Tightly linked genes on the same chromosomes show very few combinations
b) Tightly linked genes on the same chromosomes show higher combinations
c) Genes far apart on the same chromosomes show very few recombinations
d) Genes loosely linked on the same chromosomes show similar recombinations as the tightly linked ones
Answer Key:
a) Tightly linked genes on the same chromosomes show very few combinations
9. Which Mendelian idea is depicted by a cross in which the F1 generation resembles both the parents
a) Incomplete dominance
b) Law of dominance
c) Inheritance of one gene
d) Co-dominance
Answer Key:
d) Co-dominance
10. Fruit colour in squash is an example of
a) Recessive epistatsis
b) Dominant epistasis
c) Complementary genes
d) Inhibitory genes
Answer Key:
b) Dominant epistasis
11. In his classic experiments on Pea plants, Mendel did not use
a)Flowering position
b) Seed colour
c) Pod length
d) Seed shape
Answer Key:
c) Pod length
12. The epistatic effect, in which the dihybrid cross 9:3:3:1 between AaBb x AaBb is modified as
a) Dominance of one allele on another allele of both loci
b) Interaction between two alleles of different loci
c) Dominance of one allele to another alleles of same loci
d) Interaction between two alleles of same loci
Answer Key:
b) Interaction between two alleles of different loci
c) Dominance of one allele to another alleles of same loci
13. In a test cross involving F1 dihybrid more parental type offspring were produced than the recombination type offspring. This indicates
a) The two genes are located on two different chromosomes
b) Chromosomes failed to separate during meiosis
c) The two genes are linked and present on the same chromosome
d) Both of the characters are controlled by more than one gene
Answer Key:
d) Both of the characters are controlled by more than one gene
14. The genes controlling the seven pea characters studied by Mendel are known to be located on how many different chromosomes?
a) Seven
b) Six
c) Five
d) Four
Answer Key:
c) Five
15. Which of the following explains how progeny can posses the combinations of traits that none of the parent possessed?
a) Law of segregation
b) Chromosome theory
c) Law of independent assortment
d) Polygenic inheritance
Answer Key:
c) Law of independent assortment
16. “Gametes are never hybrid”. This is a statement of
a) Law of dominance
b) Law of independent assortment
c) Law of segregation
d) Law of random fertilization
Answer Key:
c) Law of segregation
17. Gene which suppresses other genes activity but does not lie on the same locus is called as
a) Epistatic
b) Supplement only
c) Hypostatic
d) Codominant
Answer Key:
a) Epistatic
18. Pure tall plants are crossed with pure dwarf plants. In the F1 generation, all plants were tall. These tall plants of F1 generation were selfed and the ratio of tall to dwarf plants obtained was 3:1. This is called
a) Dominance
b) Inheritance
c) Codominance
d) Heredity
Answer Key:
a) Dominance
19. The dominant epistatis ratio is
a) 9:3:3:1
b) 12:3:1
c) 9:3:4
d) 9:6:1
Answer Key:
b) 12:3:1
20. Select the period for Mendel’s hybridization experiments
a) 1856 - 1863
b) 1850 - 1870
c) 1857 - 1869
d) 1870 - 1877
Answer Key:
b) 1850 - 1870
21. Among the following characters which one was not considered by Mendel in his experimentation pea?
a) Stem – Tall or dwarf
b) Trichomal glandular or non-glandular
c) Seed – Green or yellow
d) Pod – Inflated or constricted
Answer Key:
b) Trichomal glandular or non-glandular
II. Short Answer Questions
12th bio botanyIII. Long Answer Questions
12th bio botanyIV. Exercise
12thbio botany
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