2/16white: 3/16green: 1/16yellow two genes interact to produce various phenotypic ratios among f2 progeny of a dihybrid cross. design a different pathway explaining each of the f2 ratios below, using hypothetical genes r and t and assuming that the dominant allele at each locus catalyzes a different reaction or performs an action leading to pigment production. the recessive allele at each locus is null (loss-of-function). begin each pathway with a colorless precursor that produces a white or albino phenotype if it is unmodified. the ratios are for f2 progeny produced by crossing wild-type f1 organisms with the genotype rrtt.

hormones in blood stream

image: dtc.ucsf.edu

endocrine glands secrete hormones into the blood stream near them; the hormones then travel in our bloodstream until it reaches its destination, called a target cell, in distance parts of the body. in the target tissue, hormones lock onto the target’s plasma membrane, called the receptor site.

condensation. good luck!

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!