A summer-squash plant that produces disc-shaped fruit is crossed with a summer-squash plant that produces long fruit. All the F1 have disc-shaped fruit. When the F1 are intercrossed, F2 progeny are produced in the following ratio:9/16 disc-shaped: 6/16 spherical fruit: 1/16 long fruit. What is the genotype of the spherical-shaped fruit?

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.

above statement is not a true statement about the open ocean because the open ocean has low levels of nutrients. most of the photosynthetic activity on earth occurs in the open ocean within the photic zone. organisms in the deep ocean are exposed to frigid temperatures and total darkness but it does not begin at the low-tide mark.