6. A biologist exposed a mosquito population to a moderate concetration of DDT, a powerful pesticide; approximately 2% of these mosquitos survived. These surving mosquitos were allowed to interdreed ane produce offspring. When the offspring were exposed to DDT, approximately 94% survived. Which of the following is the best conclusion you could draw from these observations alone?
a. DDT resistance is a benefical trait for mosquitos in the natural environment.
b. Exposure to DDT indused a mutation to DDT resistance which was inherited by the offspring.
c. A mutation for DDT resistance is a recessive gene and is expressed in homozygous individuals.
d. Exposure to DDT allows only those mosquitos to survive which already have genetic information for DDT resistance.
e. b&d are equally likely.
2007-12-02 14:45:27 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Biology
The answer is 'D'. Trust me on this. 2% of the population did not get a spontaneous mutation that provides resistance to DDT. Those alleles were already present in the population. The question is trying to see if you will fall into the trap of thinking that mutations are induced when they are needed.
2007-12-02 15:06:39 · answer #1 · answered by Anonymous · 0⤊ 0⤋
E
Chemicals can cause DNA to mutate.
Survival of the fittest - those who live through DDT the first time will reproduce (perhaps to DDT resistance gene), giving the offspring the DDT resistance gene.
2007-12-02 15:01:18 · answer #2 · answered by theshortaznswimmer 2 · 0⤊ 0⤋
The answer is D.
The answer E would mean that B could be correct. The concept behind B is "Inheritance of Aquired Characteristics" which has been totally disproved, disavowed and rejected by all Biologists. (For a while, the Russians/Soviets were the only "true believers" in the theory under the name of Lysenkoism). It was developed by a man named Lamarck.
2007-12-02 15:37:35 · answer #3 · answered by REC CHIP 3 · 0⤊ 0⤋
e
2007-12-02 14:51:08 · answer #4 · answered by Ken G 7 · 0⤊ 0⤋