Class XI & XII · Biology practice
Botany PYQs Check your understanding, bookmark questions and revisit your mistakes.
Enable JavaScript to check answers and save progress. Stored explanations remain available below.
408 questions in this collection · Page 35 of 41
Biological Classification
Match List-I with List-II.
List-I
List-II
A. Fusion of protoplasms between gametes
I. Meiosis
B. Fusion of two nuclei
II. Plasmogamy
C. Generation of haploid spores
III. Karyogamy
Choose the correct answer from the options given below:
A A-II, B-III, C-I B A-II, B-I, C-III C A-III, B-II, C-I D A-I, B-III, C-II
Show explanation
Bookmark
Try again
Plasmogamy is fusion of cytoplasm, karyogamy is fusion of nuclei and meiosis produces haploid spores.
Plant Growth And Development
Length of the stem at time 0 is 20 cm. The arithmetic growth rate is 30 cm per day. What is the length of the stem at the end of the 7th day?
A 50 cm B 170 cm C 230 cm D 460 cm
Show explanation
Bookmark
Try again
Length = 20 + (30 × 7) = 230 cm.
Biotechnology And Its Applications
The inactive form of Bt toxin is converted to the active form in the insect gut _______.
A Due to alkaline pH B Due to acidic pH C By proteases D By nucleases
Show explanation
Bookmark
Try again
The Bt toxin exists as an inactive protoxin. The alkaline pH of the insect gut solubilises the crystals and converts the protoxin into its active form.
Sexual Reproduction In Flowering Plants
How many theca are present in each lobe of a typical bilobed angiosperm anther?
A 2 B 6 C 8 D 12
Show explanation
Bookmark
Try again
A typical angiosperm anther is bilobed, and each lobe contains two theca (dithecous anther).
Biotechnology Principles And Processes
Which of the following statements about lac-operon is correct?
A Gene i is constitutively expressed B Lactose activates repressor to bind to the operator C Genes i, z, y and a share single common promoter D Galactose can act as an inducer of lac operon
Show explanation
Bookmark
Try again
The regulatory gene (i) is constitutively expressed. Allolactose, not galactose, acts as the inducer by inactivating the repressor.
Sexual Reproduction In Flowering Plants
Which of the following in the female gametophyte of an angiosperm helps in guiding the pollen tube for fertilizing the egg?
A Antipodals B Synergids C Central cell D Polar nucleus
Show explanation
Bookmark
Try again
Synergids possess a filiform apparatus that guides the pollen tube towards the egg apparatus.
Sexual Reproduction In Flowering Plants
Which of the following plants produces non-albuminous seeds?
A Wheat B Maize C Barley D Pea
Show explanation
Bookmark
Try again
Pea produces non-albuminous (exalbuminous) seeds because the endosperm is consumed during embryo development.
Sexual Reproduction In Flowering Plants
If the diploid chromosome number of a typical angiosperm is 36, what would be the chromosome number in its endosperm?
A 18 B 36 C 54 D 72
Show explanation
Bookmark
Try again
The endosperm is triploid (3n). If the diploid chromosome number is 36 (2n), then n = 18 and the endosperm chromosome number is 3n = 54.
Biotechnology Principles And Processes
During PCR, primers bind to the DNA strands in the _______ step.
A Denaturation B Extension C Annealing D Ligation
Show explanation
Bookmark
Try again
During the annealing step of PCR, primers bind to their complementary DNA sequences before DNA synthesis begins.
Biotechnology Principles And Processes
Given below are two statements:Assertion (A): In recombinant DNA technology, lysozyme is used for disrupting bacterial cells while cellulase is used for plant cells.Reason (R): Isolation of genetic material needs disruption of cells.
A Both A and R are correct and R is the correct explanation of A B Both A and R are correct but R is not the correct explanation of A C A is correct but R is not correct D A is not correct but R is correct
Show explanation
Bookmark
Try again
Lysozyme digests bacterial cell walls and cellulase digests plant cell walls. Cell disruption is necessary for DNA isolation, but the reason does not explain why different enzymes are used.
Page score: 0/40