3-In mice, the ability to run normally is a dominant trait. Mice with this trait are called running mice (R). The recessive trait causes mice to run in circles and we call these waltzing mice (r). Hair color is also inherited. Black hair (B) is dominant over brown hair (b). Suppose a h0m0zygous waltzing, heter0zygous black hair mouse was crossed with a heter0zygous running, h0m0zygous brown hair mouse. If we look at the offspring, % will be heter0zygous running and heter0zygous black hair. (Please provide a number only in the blank)

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!

several tissues working together form an organ, and several organs together make up an organisms.

the group of cell that carries out special jobs are tissue.