The first animals with simple nerve nets probably evolved about ...

[NguyenJ]

The first animals with simple nerve nets probably evolved about _________ years ago.
 
  a. 4.5 billion
 b. 3.5 billion
 c. 700 million
  d. 250 million

Question 2

Natural selection refers to the
 
  a. ability of farmers and breeders to develop animals with specific traits, such as fast horses and hairless Chihuahuas.
  b. ability to select embryos with certain characteristics during in vitro fertilization.
 c. success of one trait over another in the survival of a species.
 d. dominance of genes for one trait, such as dark eye color, over another, such as blue eye color.

[JYan]

Answer to Question 1

c

Answer to Question 2

c