Question 1: Which of the following findings from the recent rice study support Lamarck’s theory of acquired characteristics?

1. Cold-tolerant rice traits were inherited without changes in DNA sequence.
2. Hypomethylation near the ACT1 gene promoter was induced by cold exposure.
3. The ability to tolerate cold persisted across five generations.
4. Natural selection led to permanent mutations in the ACT1 gene.

Select the correct answer using the code below:

A. 1, 2 and 3 only
B. 1 and 4 only
C. 2 and 3 only
D. 1, 2, 3 and 4

 Answer: A. 1, 2 and 3 only

·         Statement 4 is incorrect: no permanent DNA mutations were responsible for cold tolerance.

Question 2: Which molecular mechanisms were reported in the cold-adapted rice study?

1. Downregulation of MET1b DNA methyltransferase under cold stress
2. Hypomethylation of ACT1 promoter leading to increased Dof1 binding
3. Permanent coding sequence mutations in ACT1
4. Multigenerational inheritance of an epiallele

Select the correct answer:

A. 1, 2 and 4 only
B. 2 and 3 only
C. 1 and 3 only
D. 3 and 4 only

Answer: A. 1, 2 and 4 only

·         Coding sequence mutations were not found; the adaptation emerged through epigenetic changes

 Question 3: Consider the following statements about the geographic distribution of ACT1 methylation in rice landraces:

1. Southern China rice landraces predominantly have hypermethylated ACT1 promoters.
2. Northern China landraces predominantly carry hypomethylated ACT1 promoters.
3. ACT1 coding sequence varied significantly between these landraces.

Which of the statements are correct?

A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2 and 3

Answer: B. 1 and 2 only

·         Statement 3 is incorrect because ACT1 coding sequences remained conserved; only methylation varied geographically.

Question 4 :Which of the following best illustrates transgenerational epigenetic inheritance observed in the rice study?

A. A plant gene mutates permanently under stress and passes to offspring
B. Cold exposure induces inheritable methylation changes without DNA mutation
C. Darwinian natural selection of random beneficial mutants
D. Single-generation physiological adaptation without hereditary transfer

Answer: B. Cold exposure induces inheritable methylation changes without DNA mutation

·         This aligns with the observed epigenetic inheritance of cold tolerance across generations.

Question 5: Which of the following terms best describes the heritable cold resistance seen in the rice study?

A. Somatic mutation
B. Horizontal gene transfer
C. Epigenetic inheritance
D. Gene flow

Answer: C. Epigenetic inheritance

·         Traits were passed down through methylation changes, not genetic code changes.

Question 6:  Which scientist’s work does the recent rice epigenetic study conceptually support?

A. Charles Darwin
B. August Weismann
C. Jean-Baptiste Lamarck
D. Gregor Mendel

Answer: C. Jean-Baptiste Lamarck

·         Because traits acquired during an organism's life were inherited by the offspring — echoing Lamarck's theory.

Question 7:Which of the following is true about gene ACT1 in the rice study?

1. It is vital for plant growth and development.
2. Its expression decreases in cold due to methylation in normal plants.
3. In cold-adapted rice, the ACT1 gene was deleted.
4. ACT1 expression continued in cold-adapted rice due to hypomethylation.

Select the correct code:

A. 1 and 2 only
B. 1, 2 and 4 only
C. 3 and 4 only
D. 2 and 3 only

Answer: B. 1, 2 and 4 only

·         ACT1 was not deleted in cold-adapted plants; it was still expressed due to reduced methylation.

Question 8: Which process allows gene expression to be altered without changing the underlying DNA sequence?
A. Mutation
B. Transcription
C. Translation
D. Epigenetic modification

Answer: D

 

Question 9: What was the key finding of the 2024 rice cold-tolerance study?
A. Mutation in ACT1 gene improved survival
B. Gene ACT1 was removed from genome
C. ACT1 stayed active due to absence of methylation
D. DNA sequence was changed by cold stress

Answer: C