DDT is an insecticide that was used extensively in the mid-1900s to kill mosquitoes. It was very effective at first, but after a few decades DDT became less effective at killing mosquitoes because many populations had evolved resistance to DDT. Which of the following conditions would biologists say was required for the evolution of DDT resistance in a population? a) A few mosquitoes in the population were resistant to DDT before it was ever used.
b) Mosquitoes in the population learned to adapt to the high levels of DDT in the environment.
c) The mosquito population needed to evolve DDT resistance in order to avoid extinction.
d) Exposure to DDT caused specific, nonrandom mutations for DDT resistance within the population.

the right answer is a. skin cells forming from sunlight.

the liver is an organ endowed with a fantastic ability to regenerate

. thus, if a hepatectomy (ablation) of 70% of the hepatic mass is performed in the rat, there is complete recovery in 7 to 10 days.

prokaryotes are beings that have existed since the existence of life on earth, and do not come from another realm.

ribosomes are organelles that exist naturally in eukaryotes, either in free form or attached to the endoplasmic reticulum.

click to let others know, how is it

mark brainliest and have a great day!

age range would be the answer

it's not c. i took the quiz and got it wrong. so my best guess is b.

have a great day, and hope this .

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]