Question

6. Can a genetic mutation sometimes cause someone to grow an extra arm?
__ true
__ false

7. Mutations are the changes to the nucleotide sequence of the genetic material of an organism?
__ true
__ false

8. Mutations can not be caused by copying errors in the genetic material during cell division?
__ true
__ false

9. Which of these factor(s) are associated with DNA damage?

A. Alkylating agents
B. UV
C. All of these
D. Free Radicals

Answer 1

6) Our body structure and the position and development of arms, legs, different organs are mediated by the Homeotic genes(HOX genes) during development. These genes even regulate the number of arms and legs to be maintained. Mutations in such Homeotic genes can leads to the development of uneven development of structure and form can leads to extra arms and legs. Thus the statement is TRUE.

7) If there is any change occurs in the nucleotide sequence of DNA, the change is called Mutation. This leads to several disorders and even cancer. Hence, the statement is TRUE.

8) DNA is copied for the production of new daughter strands by a process called replication. The errors in the copying of DNA sometimes leads to mutations in the daughter strands. Hence, the statement is FALSE.

9) Mutations are the changes in nucleotide sequence. These can be caused by various factors like UV rays, Chemicals like alkylating agents, free radicals, etc. UV rays causes Thymin dimers and leads to inhibition of transcription. Reactive oxygen species or free radicals directly damages the DNA leads to mutations. Alkylating agents causes unnecessary alkyl (methyl) groups causes abnormalities. Hence, all the given options are correct. Thus option (C) is the answer.