Unit 7: Genetics and Evolution — Online MCQ Test
BIOLOGY · NEET (All) · NEET
Practice Unit 7: Genetics and Evolution with a free chapter-wise online MCQ test.
This chapter covers: Heredity and variation: Mendelian Inheritance; Deviations from Mendelism-Incomplete dominance Co-dominance Multiple alleles and Inheritance of blood groups Pleiotropy; Elementary i....
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Unit 7: Genetics and Evolution — Important Questions & Answers
Name the enzyme that facilitates opening of DNA helix during transcription.
- A. DNA helicase
- B. DNA polymerase
- C. RNA polymerase
- D. DNA ligase
Answer: C. RNA polymerase
During transcription, DNA-dependent RNA polymerase is the enzyme that initiates the process, opens the DNA helix, and synthesizes RNA.
During transcription, DNA-dependent RNA polymerase is the enzyme that initiates the process, opens the DNA helix, and synthesizes RNA.
If the distance between two consecutive base pairs is 0.34 nm and the total number of base pairs of a DNA double helix in a typical mammalian cell is 6.6 x 10^9 bp, then the length of the DNA is approximately:
- A. 2.5 meters
- B. 2.2 meters
- C. 2.7 meters
- D. 2.0 meters
Answer: B. 2.2 meters
Length = (Number of bp) * (Distance per bp) = (6.6 * 10^9) * (0.34 * 10^-9 m) = 2.244 meters, which is approximately 2.2 meters.
Length = (Number of bp) * (Distance per bp) = (6.6 * 10^9) * (0.34 * 10^-9 m) = 2.244 meters, which is approximately 2.2 meters.
The first phase of translation is:
- A. Recognition of DNA molecule
- B. Aminoacylation of tRNA
- C. Recognition of an anti-codon
- D. Binding of mRNA to ribosome
Answer: B. Aminoacylation of tRNA
The activation of amino acids and their attachment to their specific tRNAs (aminoacylation) is the charging step before translation begins on the ribosome.
The activation of amino acids and their attachment to their specific tRNAs (aminoacylation) is the charging step before translation begins on the ribosome.
Flippers of Penguins and Dolphins are examples of:
- A. Convergent evolution
- B. Industrial melanism
- C. Natural selection
- D. Adaptive radiation
Answer: A. Convergent evolution
Analogous organs (different structure, same function) like the flippers of penguins and dolphins demonstrate convergent evolution.
Analogous organs (different structure, same function) like the flippers of penguins and dolphins demonstrate convergent evolution.
Identify the wrong statement with reference to the gene 'I' that controls ABO blood groups.
- A. A person will have only two of the three alleles.
- B. When IA and IB are present together, they express same type of sugar.
- C. Allele 'i' does not produce any sugar.
- D. The gene (I) has three alleles.
Answer: B. When IA and IB are present together, they express same type of sugar.
When IA and IB are present together, they express different sugars (A and B), resulting in AB blood group due to codominance, not the same sugar.
When IA and IB are present together, they express different sugars (A and B), resulting in AB blood group due to codominance, not the same sugar.
Embryological support for evolution was disapproved by:
- A. Alfred Wallace
- B. Charles Darwin
- C. Oparin
- D. Karl Ernst von Baer
Answer: D. Karl Ernst von Baer
Karl Ernst von Baer proposed that embryos do not pass through adult stages of lower animals, effectively disproving the biogenetic law proposed by Haeckel.
Karl Ernst von Baer proposed that embryos do not pass through adult stages of lower animals, effectively disproving the biogenetic law proposed by Haeckel.
What is the pattern of inheritance for polygenic trait?
- A. Mendelian inheritance pattern
- B. Non-mendelian inheritance pattern
- C. Autosomal dominant pattern
- D. X-linked recessive inheritance pattern
Answer: B. Non-mendelian inheritance pattern
Polygenic traits are controlled by multiple genes, which does not follow the classical Mendelian patterns of dominant-recessive allele interactions for single gene traits.
Polygenic traits are controlled by multiple genes, which does not follow the classical Mendelian patterns of dominant-recessive allele interactions for single gene traits.
Which one from those given below is the period for Mendel's hybridization experiments?
- A. 1870 - 1877
- B. 1856 - 1863
- C. 1840 - 1850
- D. 1857 - 1869
Answer: B. 1856 - 1863
According to NCERT, Gregor Mendel conducted his hybridization experiments on garden pea plants for 7 years between 1856 and 1863.
According to NCERT, Gregor Mendel conducted his hybridization experiments on garden pea plants for 7 years between 1856 and 1863.
Which of the following pairs is wrongly matched?
- A. Starch synthesis in pea : Multiple alleles
- B. T.H. Morgan : Linkage
- C. XO type sex determination : Grasshopper
- D. ABO blood grouping : Co-dominance
Answer: A. Starch synthesis in pea : Multiple alleles
Starch synthesis in pea is an example of incomplete dominance (or codominance involving the R/r alleles affecting branching of starch), but more accurately it is cited in NCERT as an example of codominance/incomplete dominance — NOT multiple alleles. Multiple alleles is exemplified by ABO blood grouping. Hence starch synthesis in pea paired with 'multiple alleles' is the wrong match.
Starch synthesis in pea is an example of incomplete dominance (or codominance involving the R/r alleles affecting branching of starch), but more accurately it is cited in NCERT as an example of codominance/incomplete dominance — NOT multiple alleles. Multiple alleles is exemplified by ABO blood grouping. Hence starch synthesis in pea paired with 'multiple alleles' is the wrong match.
Select the correct statement:
- A. Franklin Stahl coined the term 'linkage'.
- B. Transduction was discovered by S. Altman.
- C. Spliceosomes take part in translation.
- D. Punnett square was developed by a British scientist.
Answer: D. Punnett square was developed by a British scientist.
Reginald Crundall Punnett, a British geneticist, developed the Punnett square. The term 'linkage' was coined by T.H. Morgan (not Franklin Stahl). Transduction was discovered by Joshua Lederberg and Norton Zinder (not S. Altman). Spliceosomes take part in splicing/processing of pre-mRNA (post-transcriptional), not translation.
Reginald Crundall Punnett, a British geneticist, developed the Punnett square. The term 'linkage' was coined by T.H. Morgan (not Franklin Stahl). Transduction was discovered by Joshua Lederberg and Norton Zinder (not S. Altman). Spliceosomes take part in splicing/processing of pre-mRNA (post-transcriptional), not translation.