Plus One / 12th Botany - Book Back Answers - Chapter 3 - English Medium
Tamil Nadu Board 12th Standard Botany - Chapter 3: Book Back Answers and Solutions
This post covers the book back answers and solutions for Chapter 3 – Botany from the Tamil Nadu State Board 12th Standard 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 Botany Chapter 3 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!
Unit 3 - Chromosomal Basis of Inheritance
I. Multiple Choice Questions
1. An allohexaploidy contains
a) Six different genomes
b) Six copies of three different genomes
c) Two copies of three different genomes
d) Six copies of one genome
Answer Key:
c) Two copies of three different genomes
2. Match list I with list II
a) A-i, B-iii, C-ii, D-iv
b) A-ii, B-iii, C-iv, D-i
c) A-ii, B-iii, C-i, D-iv
d) A-iii, B-ii, C-i, D-iv
Answer Key:
c) A-ii, B-iii, C-i, D-iv
3. Which of the following sentences are correct?
1. The offspring exhibit only parental combinations due to incomplete linkage
2. The linked genes exhibit some crossing over in complete linkage
3. The separation of two linked genes are possible in incomplete linkage
4. Crossing over is absent in complete linkage
a) 1 and 2
b) 2 and 3
c) 3 and 4
d) 1 and 4
Answer Key:
c) 3 and 4
4. Due to incomplete linkage in maize, the ratio of parental and recombinants are
a) 50:50
b) 7:1:1:7
c) 96.4: 3.6
d) 1:7:7:1
Answer Key:
b) 7:1:1:7
a) Six different genomes
b) Six copies of three different genomes
c) Two copies of three different genomes
d) Six copies of one genome
Answer Key:
c) Two copies of three different genomes
2. Match list I with list II
|
List I
|
List II
|
|
A. A pair
of chromosomes extra with diploid
|
i)
monosomy
|
|
B. One
chromosome extra to the diploid
|
ii)
tetrasomy
|
|
C. One
chromosome loses from diploid
|
iii)
trisomy
|
|
D. Two
individual chromosomes lose from diploid
|
iv)
double monosomy
|
b) A-ii, B-iii, C-iv, D-i
c) A-ii, B-iii, C-i, D-iv
d) A-iii, B-ii, C-i, D-iv
Answer Key:
c) A-ii, B-iii, C-i, D-iv
3. Which of the following sentences are correct?
1. The offspring exhibit only parental combinations due to incomplete linkage
2. The linked genes exhibit some crossing over in complete linkage
3. The separation of two linked genes are possible in incomplete linkage
4. Crossing over is absent in complete linkage
a) 1 and 2
b) 2 and 3
c) 3 and 4
d) 1 and 4
Answer Key:
c) 3 and 4
4. Due to incomplete linkage in maize, the ratio of parental and recombinants are
a) 50:50
b) 7:1:1:7
c) 96.4: 3.6
d) 1:7:7:1
Answer Key:
b) 7:1:1:7
5. The point mutation sequence for transition, transition, transversion and transversion in DNA are
a) A to T, T to A, C to G and G to C
b) A to G, C to T, C to G and T to A
c) C to G, A to G, T to A and G to A
d) G to C, A to T, T to A and C to G
Answer Key:
c) C to G, A to G, T to A and G to A
6. If haploid number in a cell is 18. The double monosomic and trisomic number will be
a) 34 and 37
b) 34 and 35
c) 37 and 35
d) 17 and 19
Answer Key:
b) 34 and 35
7. Changing the codon AGC to AGA represents
a) missense mutation
b) nonsense mutation
c) frameshift mutation
d) deletion mutation
Answer Key:
a) missense
8. Assertion (A): Gamma rays are generally use to induce mutation in wheat varieties.
Reason (R): Because they carry lower energy to non-ionize electrons from atom
a) A and R are correct
b) A is correct. R is wrong
c) A is wrong. R is correct
d) A and R are wrong
Answer Key:
b) A is correct. R is
9. Which one of
the following pairs of codons is correctly matched with their function or the
signal for the particular amino acid?
a) UUA, UCA - Leucine
b) GUU, GCU - Alanine
c) UAG, UGA - Stop
d) AUG, ACG – Start / Methionine
Answer Key:
c) UAG, UGA - Stop
10. Removal of introns and joining of exons in a defined order during transcription is called
a) Splicing
b) Looping
c) Inducing
d) Slicing
Answer Key:
a) Splicing
11. If one strand of DNA has the nitrogenous base sequence as ATCTG, what would be the complementary RNA strand sequence?
a) ATCGU
b) TTAGU
c) UAGAC
d) AACTG
Answer Key:
c) UAGAC
12. Removal of RNA polymerase III nucleoplasm will affect the synthesis of
a) rRNA
b) tRNA
c) hnRNA
d) mRNA
Answer Key:
b) tRNA
13. DNA dependent RNA polymerase catalyzes transcription on one strand of the DNA which is called the
a) Alpha strand
b) Anti strand
c) Template strand
d) Coding strand
Answer Key:
b) Anti strand
14. Which of the following correctly represents the flow of genetic information?
a) DNA 🠒 RNA 🠒 Protein
b) RNA 🠒 DNA 🠒 Protein
c) RNA 🠒 Protein 🠒 DNA
d) Protein 🠒 RNA 🠒 DNA
Answer Key:
a) DNA 🠒 RNA 🠒 Protein
15. Initiation codon is
a) UUU
b) UGA
c) AUG
d) UAG
Answer Key:
c) AUG
16. A eukaryotic gene contains two kinds of base sequences which of these plays an important role in protein synthesis?
a) Introns
b) Exons
c) Both a and b
d) None of the above
Answer Key:
b) Exons
17. Codon – anticodon interactions occur by
a) Covalent bond
b) Electrostatic interactions
c) Hydrogen bonds
d) Hydrophobic interaction
Answer Key:
c) Hydrogen bonds
18. Which of the following RNA polymerases is responsible for the transcription of protein coding genes in eukaryotes?
a) RNA Pol I
b) RNA Poly II
c) RNA Pol III
d) RNA Pol IV
Answer Key:
b) RNA Poly II
19. How are RNA molecules transported out of the nucleus
a) Passive diffusion through the membrane
b) Through membrane pores in an energy independent process
c) Through membrane pores in an energy dependent process
d) Through a channel in the membrane that leads to the endoplastic reticulation
Answer Key:
c) Through membrane pores in an energy dependent process
20. During translation the codon in mRNA is actually “read” by
a) The A site in the ribosomes
b) The P site in the ribosomes
c) The anticodon in a tRNA
d) The anticodon is an amino acid
Answer Key:
c) The anticodon in a tRNA
21. A complex of ribosome attached to a single strand of RNA is known as
a) Polysome
b) Polymer
c) Polypeptide
d) Okazaki fragment
Answer Key:
a) Polysome
22. Which of the following is the start codon
a) AUG
b) UGA
d) UAA
d) UAG
Answer Key:
a) AUG
23. What is true about tRNA?
a) It binds with an amino acid at its 3’ end
b) It has 5 double stranded regions
c) It has a codon at one end which recognizes the anticodon of mRNA
d) It looks like clover leaf in the three D structure
Answer Key:
a) It binds with an amino acid at its 3’ end
24. Which one of the following hydrolysis internal phosphodiester bonds in a polynucleotide chain?
a) Lipase
b) Exonuclease
c) Endonuclease
d) Protease
Answer Key:
c) Endonuclease
25. DNA element with ability to change position is called
a) Cistron
b) Transposon
c) Intron
d) Recon
Answer Key:
b) Transposon
26. Spliceosomes are not found in cells of
a) Plants
b) Fungi
c) Animals
d) Bacteria
Answer Key:
d) Bacteria
27. During DNA replication Okazaki fragments are used to elongate
a) The leading strand towards replication fork
b) The lagging strand towards replication fork
c) The leading strand away from replication fork
d) The lagging strand away from replication fork
Answer Key:
d) The lagging strand away from replication fork
a) UUA, UCA - Leucine
b) GUU, GCU - Alanine
c) UAG, UGA - Stop
d) AUG, ACG – Start / Methionine
Answer Key:
c) UAG, UGA - Stop
10. Removal of introns and joining of exons in a defined order during transcription is called
a) Splicing
b) Looping
c) Inducing
d) Slicing
Answer Key:
a) Splicing
11. If one strand of DNA has the nitrogenous base sequence as ATCTG, what would be the complementary RNA strand sequence?
a) ATCGU
b) TTAGU
c) UAGAC
d) AACTG
Answer Key:
c) UAGAC
12. Removal of RNA polymerase III nucleoplasm will affect the synthesis of
a) rRNA
b) tRNA
c) hnRNA
d) mRNA
Answer Key:
b) tRNA
13. DNA dependent RNA polymerase catalyzes transcription on one strand of the DNA which is called the
a) Alpha strand
b) Anti strand
c) Template strand
d) Coding strand
Answer Key:
b) Anti strand
14. Which of the following correctly represents the flow of genetic information?
a) DNA 🠒 RNA 🠒 Protein
b) RNA 🠒 DNA 🠒 Protein
c) RNA 🠒 Protein 🠒 DNA
d) Protein 🠒 RNA 🠒 DNA
Answer Key:
a) DNA 🠒 RNA 🠒 Protein
15. Initiation codon is
a) UUU
b) UGA
c) AUG
d) UAG
Answer Key:
c) AUG
16. A eukaryotic gene contains two kinds of base sequences which of these plays an important role in protein synthesis?
a) Introns
b) Exons
c) Both a and b
d) None of the above
Answer Key:
b) Exons
17. Codon – anticodon interactions occur by
a) Covalent bond
b) Electrostatic interactions
c) Hydrogen bonds
d) Hydrophobic interaction
Answer Key:
c) Hydrogen bonds
18. Which of the following RNA polymerases is responsible for the transcription of protein coding genes in eukaryotes?
a) RNA Pol I
b) RNA Poly II
c) RNA Pol III
d) RNA Pol IV
Answer Key:
b) RNA Poly II
19. How are RNA molecules transported out of the nucleus
a) Passive diffusion through the membrane
b) Through membrane pores in an energy independent process
c) Through membrane pores in an energy dependent process
d) Through a channel in the membrane that leads to the endoplastic reticulation
Answer Key:
c) Through membrane pores in an energy dependent process
20. During translation the codon in mRNA is actually “read” by
a) The A site in the ribosomes
b) The P site in the ribosomes
c) The anticodon in a tRNA
d) The anticodon is an amino acid
Answer Key:
c) The anticodon in a tRNA
21. A complex of ribosome attached to a single strand of RNA is known as
a) Polysome
b) Polymer
c) Polypeptide
d) Okazaki fragment
Answer Key:
a) Polysome
22. Which of the following is the start codon
a) AUG
b) UGA
d) UAA
d) UAG
Answer Key:
a) AUG
23. What is true about tRNA?
a) It binds with an amino acid at its 3’ end
b) It has 5 double stranded regions
c) It has a codon at one end which recognizes the anticodon of mRNA
d) It looks like clover leaf in the three D structure
Answer Key:
a) It binds with an amino acid at its 3’ end
24. Which one of the following hydrolysis internal phosphodiester bonds in a polynucleotide chain?
a) Lipase
b) Exonuclease
c) Endonuclease
d) Protease
Answer Key:
c) Endonuclease
25. DNA element with ability to change position is called
a) Cistron
b) Transposon
c) Intron
d) Recon
Answer Key:
b) Transposon
26. Spliceosomes are not found in cells of
a) Plants
b) Fungi
c) Animals
d) Bacteria
Answer Key:
d) Bacteria
27. During DNA replication Okazaki fragments are used to elongate
a) The leading strand towards replication fork
b) The lagging strand towards replication fork
c) The leading strand away from replication fork
d) The lagging strand away from replication fork
Answer Key:
d) The lagging strand away from replication fork
II. Short Answer Questions
12th bio botanyIII. Long Answer Questions
12th bio botanyIV. Exercise
12thbio botany
0 Comments:
Post a Comment