Cross the long-finned fish with short-finned fish; if the offspring are all long-finned, the long-finned parent is homozygous.
Imagine that long fins in zebrafish is a dominant trait. A breeder wants to set up a breeding program beginning with homozygous dominant long-finned fish. If she obtains a handful of the rare long-finned fish, how can she tell which if any of these are homozygous for the trait?
True or False

True

Explanation:

In order for the breeder to know if the long fined fish are homozygous. He will have to cross the Long finned with short finned

If the long finned was homozygous, all the F1 will be long finned zebrafish. This is because long fin is dominant over short fin.

However, if the long finned zebrafish were heterozygous. The cross will produce two long finned and two short finned zebra fish.

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!