In a dihybid cross, what does observing a ratio of 9:3:3:1 indicate?

Consider darwin's first writings on the theory of natural selection. an important point of darwin's essay on the principle of population, written in 1798, was a peer's observation that in nature plants and animals produce far more offspring than can survive, this observation can be attributed to a) charles lyell. b) thomas malthus. c) jean-baptiste lamarck. d) johann friedrich meckel.

What is the difference between an igneous, sedimentary and metamorphic rock

Identify the composition of oceanic and continental crystal rocks.in a model of earth’s interior,where would these rocks appear?