What are genes?
a. the observable characteristic
b. the expressed trait
c. the basic unit of inheritance
d. the measurable factor

Explain how paleontologists use trilobite fossils as index fossils for various geologic time periods.

The table above shows five different types of chromosomal abnormalities that can occur during meiosis. they result in either an individual having too many or too few chromosomes in their genome. what is the most likely cause of these chromosomal abnormalities?

Which of the following is one way in which organisms such as clown fish and sea turtles are able to overcome the many dangers that their offspring encounter and ensure that their species population numbers stay relatively steady