CBSE
ADDITIONAL PRACTICE QUESTIONS
Biology (044)
Class XII| 2023–24
Max Marks: 80 Time: 3 hours
General Instructions:
(i) All questions are compulsory.
(ii) The question paper has five sections and 33 questions. All questions are compulsory.
(iii) Section–A has 16 questions of 1 mark each; Section–B has 5 questions of 2 marks
each; Section– C has 7 questions of 3 marks each; Section– D has 2 case-based
questions of 4 marks each; and Section–E has 3 questions of 5 marks each.
(iv) There is no overall choice. However, internal choices have been provided in some
questions. A student has to attempt only one of the alternatives in such questions.
(v) Wherever necessary, neat and properly labeled diagrams should be drawn.
Section A
Q.Nos. Questions Marks
1 During the pollen grain formation, the generative cell divides to give rise to 1
the two male gametes.
What is the ploidy of the generative cell?
(a) n
(b) 2n
(c) 3n
(d) 4n
2 Kiwi is a dioecious species. Which of the following methods can be 1
definitely RULED OUT as a possible mode of pollination in its case?
P) cleistogamous autogamy
Q) chasmogamous autogamy
R) geitonogamy
S) xenogamy
(a) only P and R
, (b) only P and Q
(c) only Q and S
(d) only P, Q and R
3 Arun thinks that identifying the exact mRNA sequence from the protein 1
sequence is difficult.
Is he correct and why?
(a) No, as the genetic code is universal.
(b) Yes, as the genetic code is degenerate.
(c) No, as the mRNA is translated into a protein sequence.
(d) Yes, as the mRNA contains introns which are non-coding sequences.
4 Crickets are insects that follow the XO type of sex determination. Which of 1
the following statements is ALWAYS TRUE about this type of sex
determination?
(a) Eggs that have an O chromosome will give rise to a male cricket.
(b) Eggs that have an X chromosome will give rise to a female cricket.
(c) Sperms that have an X chromosome will give rise to a male cricket.
(d) Sperms that have an O chromosome will give rise to a male cricket.
5 Oysters are generally either dark or light in colour. Dark oysters excel in 1
dark environments, while light oysters thrive in bright environments.
Intermediate-coloured oysters are disadvantaged, lacking effective
camouflage in either setting.
Which type of natural selection does this phenomenon exemplify?
(a) directional
(b) stabilising
(c) disruptive
(d) (The phenomenon described does not exemplify natural selection.)
6 A team of archaeologists found a fossilized skeleton of a human-like 1
creature with a brain capacity of more than 700cc. The structure and its
associated findings also show evidence that this creature could use tools for
hunting.
Which stage of human evolution is this creature NOT from?
(a) Homo erectus
ADDITIONAL PRACTICE QUESTIONS
Biology (044)
Class XII| 2023–24
Max Marks: 80 Time: 3 hours
General Instructions:
(i) All questions are compulsory.
(ii) The question paper has five sections and 33 questions. All questions are compulsory.
(iii) Section–A has 16 questions of 1 mark each; Section–B has 5 questions of 2 marks
each; Section– C has 7 questions of 3 marks each; Section– D has 2 case-based
questions of 4 marks each; and Section–E has 3 questions of 5 marks each.
(iv) There is no overall choice. However, internal choices have been provided in some
questions. A student has to attempt only one of the alternatives in such questions.
(v) Wherever necessary, neat and properly labeled diagrams should be drawn.
Section A
Q.Nos. Questions Marks
1 During the pollen grain formation, the generative cell divides to give rise to 1
the two male gametes.
What is the ploidy of the generative cell?
(a) n
(b) 2n
(c) 3n
(d) 4n
2 Kiwi is a dioecious species. Which of the following methods can be 1
definitely RULED OUT as a possible mode of pollination in its case?
P) cleistogamous autogamy
Q) chasmogamous autogamy
R) geitonogamy
S) xenogamy
(a) only P and R
, (b) only P and Q
(c) only Q and S
(d) only P, Q and R
3 Arun thinks that identifying the exact mRNA sequence from the protein 1
sequence is difficult.
Is he correct and why?
(a) No, as the genetic code is universal.
(b) Yes, as the genetic code is degenerate.
(c) No, as the mRNA is translated into a protein sequence.
(d) Yes, as the mRNA contains introns which are non-coding sequences.
4 Crickets are insects that follow the XO type of sex determination. Which of 1
the following statements is ALWAYS TRUE about this type of sex
determination?
(a) Eggs that have an O chromosome will give rise to a male cricket.
(b) Eggs that have an X chromosome will give rise to a female cricket.
(c) Sperms that have an X chromosome will give rise to a male cricket.
(d) Sperms that have an O chromosome will give rise to a male cricket.
5 Oysters are generally either dark or light in colour. Dark oysters excel in 1
dark environments, while light oysters thrive in bright environments.
Intermediate-coloured oysters are disadvantaged, lacking effective
camouflage in either setting.
Which type of natural selection does this phenomenon exemplify?
(a) directional
(b) stabilising
(c) disruptive
(d) (The phenomenon described does not exemplify natural selection.)
6 A team of archaeologists found a fossilized skeleton of a human-like 1
creature with a brain capacity of more than 700cc. The structure and its
associated findings also show evidence that this creature could use tools for
hunting.
Which stage of human evolution is this creature NOT from?
(a) Homo erectus
