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.
Examples of animals
These two desert arthropods, a scorpion and a cicada, have evolved very different approaches to livi
Wasp ocelli (simple eyes) and dorsal part of the compound eyes; also showing fine, unbranched hairs
Wild chimpanzees make and use simple tools to obtain food, learning tool making from one another.
The 2012 U.S. presidential campaign rang with “get tough” cries to end Iran’s nuclear capacity and c
Simple Decorating Techniques: Cake comb