Many of the color varieties of summer squash are determined by several interacting loci: aa or aa gives white, aabb or aabb gives yellow, and aabb produces green. crosses among heterozygotes give a 12: 3: 1 ratio. what type of gene interaction would account for these results?

Cells tend to have a relatively small and uniform size. why aren’t cells larger?

What kinds of molecules can pass through the cell membrane without any problem?

The diagram below shows the layers of a rock having a trilobite: a rock column labeled rock is shown. the column has three layers. the bottommost layer of the rock has one shaded rhomboid shape, the middle layer has a rhombus with a diagonal along with two identical organisms marked as, trilobite, in the key, the top layer has two semicircles. a key is shown on the right side of the diagram. the shaded rhombus is marked as a, the rhombus with the diagonal is marked as b, the semicircle is marked as c which statement about the rock fossils is true?