Select all that apply Select all of the following that describe choanocytes. Multiple select question. They form the pinacoderm They can trap and phagocytize food particles They secrete spicules and the collagen that forms spongin They maintain a current of water through the canals of the sponge They are flagellated collar cells

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Liquid water turns into water vapor at which step in the water cycle

Suppose you have monohybrid pea plants in your garden and find that they produce round seed to wrinkled seeds in the ratio of 3: 1. if the allele are designated (r & r) receptively. what is the probable genotypes of the round seeds which produced f 1 ? rr & rr rr only rr & rr rr only rr only