LIFE SCIENCE

OBJECTIVE LIFE SCIENCE

EVOLUTION

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Mutations are
A
Long Time evolutionary events
B
Short time evolutionary events
C
Mistakes in the genetic code
D
When an organism looks very similar in physical resemblance to other objects
Explanation: 

Detailed explanation-1: -Mutations result either from errors in DNA replication or from the damaging effects of mutagens, such as chemicals and radiation, which react with DNA and change the structures of individual nucleotides. All cells possess DNA-repair enzymes that attempt to minimize the number of mutations that occur (Section 14.2).

Detailed explanation-2: -Sometimes, gene variants (also known as mutations) prevent one or more proteins from working properly. By changing a gene’s instructions for making a protein, a variant can cause a protein to malfunction or to not be produced at all.

Detailed explanation-3: -When a “mistake” is made in the DNA sequence or chromosome which causes the wrong amino acid or group of wrong amino acids to be placed into a polypeptide chain. This results a different or altered protein. Mutation can be GOOD or BAD. Bad mutations lead to an unhealthy organism which are unfit for their environment.

Detailed explanation-4: -an error in the DNA code of a single gene. The genetic error may be due to a mutation that is spontaneous or one caused by an environmental factor, such as radiation.

Detailed explanation-5: -Of course, not all mutations are “bad.” But, because so many mutations can cause cancer, DNA repair is obviously a crucially important property of eukaryotic cells. However, too much of a good thing can be dangerous.

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