The population in south africa is more prone to sickle cell anemia (genotype “ss”). people with genotype “ss” survive only up to 14-15 years of age. people with “ss” are prone to malaria because the parasite resides inside their rbcs. people with genotype "ss" are resistant to malaria because the parasite cannot reside inside their rbcs, and they can live a normal life (without sickle cell anemia). what kind of evolutionary force must be operative in south africa?

Indicate the coat color and the proportion of offspring with that color for each of the following crosses of rabbits. assume all are homozygous. albino x albino a) 1/4 chinchilla, 3/4, agouti b) 3/4 albino, 1/4 chinchilla c) all albino

What pattern of migration do whales follow?

Astudent from one of the research labs is having trouble preparing a slide for examination and photographing. the bacterial slide that he has brought to you was prepared using a commercially purchased stain. he has asked for your in determining what he is doing wrong so that he can change the lab protocols and continue on with his project. after examining the slide under oil immersion, you determine that no bacteria are present even though the student is able to show you the culture he used to make that slide that has visible growth in the liquid medium. which of the following statements does not explain the fact that there are no bacteria present on the student’s slide? by not allowing a glass slide to completely air dry before heat fixation, the flame will cause the surrounding water to boil and this will damage the bacterial cell. overheating during the fixation step boiled the water within the bacterial cells and resulted in the cells bursting. insufficient heating of the slide did not drive out the thin layer of water and this resulted in minimal bonding between the bacteria and the glass slide. rinsing with alcohol during the washing step stripped the bacteria off the glass slide. rinsing with alcohol during the washing step stripped the bacteria off the glass slide.