Which of the following explains why the allele for sickle-cell disease remains at a relatively high level in the population?
a) it is the dominant allele.
b) it confers protection from malaria to carriers.
c) it is not harmful enough to be selected against.
d) it keeps returning to the population through mutation.

Getting rid of my account might as well do it with some fun make sure to read all of this it is hilarious a plane was about to crash and there were 5 people on board and only 4 parachutes. the first person said: " i am roy keane, one of the best footballers in ireland. i am worth a lot of money and my fans need me so i think i should be saved." the others agreed and gave him one of the parachutes and off he went. the second person said: "i am gerry adams, a radical irish politician who can really my country and i think i should be saved." the others said: "o.k.", and gave him a parachute. the third person said: "i am george bush, president of the most powerful country in the world. everyone knows i am a really nice guy and everyone thinks i am stupid,but i'm not, so i am taking a parachute." and off he went. there were two people left, the pope and a 10 year old schoolgirl. the pope said: "child, i am old and frail and have lived my life while you are young, with everything before you. you take the parachute and i will stay with the aircraft and take my chance." "it's o.k." said the girl, "there are still two bush picked up my schoolbag."

Which organism is the producer in this food web? 7th grade question. a) arthropods b) birds c) fungi d) plants

What evidence supports the law of conservation of energy? a) mechanical energy is converted to chemical energy during photosynthesis. b) oxygen is made from the breakdown of carbon dioxide during photosynthesis. c)energy is absorbed by chlorophyll and becomes chemical energy during photosynthesis. d)the sun gives off light energy that is absorbed by plants.