Which of the following is not true of mendel's experiment? a. mendel crossed two true-breeding plants. b. the yellow trait seemed to disappear in the first cross. c. the yellow trait reappeared in the second cross. d. mendel proposed that the green pods were recessive.

The correct answer is option (D) Mendel proposed that the green pods were recessive.

Gregor Mendel discovered the principles of heredity with his experiments on garden pea plant. He crossed two true- breeding characters like tall and dwarf, round and wrinkled seeds, axial and terminal flowers and green pod and yellow pods of the seeds.

When he crossed the pea plants having domiant green pod (GG) with recessive yellow pod (gg). The gametes G and g produced an F 1 generation hybrid Gg which was green in colour. The yellow trait had disappeared. In the F 2 generation obtained by crossing Green (Gg) plants produced, three green plants and one yellow plant showing the reappearance of the yellow trait.

Thus, mendel crossed two true-breeding plants of pod colour, the dominant green and the recessive yellow, showing the disappearence and reappearence of the yellow trait in the first and second generation respectively.

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!