Study Guide Chapter 3

Question 1

What are 4 criteria for defining populations?

Answer 1

Same species of organism.
Located in the same location.
At the same time.
And showing signs of reproduction. (Offspring are present within the group.)

Question 2

What is an allele?

Answer 2

A version of a gene, such as blue or brown for eye color.

Question 3

How many alleles are there for a trait?

Answer 3

At least 2 alleles for a trait sometimes several required

Question 4

What is adaptation?

Answer 4

a specific variation that is or becomes a common trait within a population because it helps the species better survive in their environment

Question 5

What are examples of adaptation?

Answer 5

Clownfish are naturally slow swimmers because of their rounder caudal find that help them make quick darting movements. Over time, they have become resistant to the stings of the sea anemones in which they live because they secrete a mucus which coats and protects the body. This allows the fish to hide from predators and provides it with a safe place to live.

Question 6

What are mutations?

Answer 6

Random changes that occur in an organisms DNA. Some help individuals survive in their environment and reproduce. Some mutations have no effect

Question 7

Explain the Hardy-Weinberg theorem.

Answer 7

A set of equations used to follow allele frequency within a population (also considered gene pool)

Question 8

What are five conditions for a population considered in a state of Hardy Weinberg equilibrium?

Answer 8

Large population must exist
No migration in or out is occurring at that time
No mutations are occurring within the genome
Random mating is occurring
No natural selection is occurring

Question 9

What terms are discussed in Origin of species? Who wrote it? When?

Answer 9

The similarities and differences that exist among species
The adaptation that evolved in species in order to survive an environment
Darwin write this book on November 24 1859 it was published.

Question 10

What are homologous structures?

Answer 10

Body structures that are similar in structure to other species’ comparative parts.

Question 11

What are embryological Homologies?

Answer 11

Common stages of development that embryos go through

Question 12

What are Molecular Homologies?

Answer 12

Refers to DNA nucleotide sequences being exact in order and function.

Question 13

What is natural selection?

Answer 13

Survival of the fittest.

Question 14

What is artificial selection?

Answer 14

This is where man selects what traits are desirable (beneficial) in a species.

Question 15

What is sedimentary rock?

Answer 15

is mostly formed by being at the bottom of a body of water.

Question 16

What is the theory of Catastrophism?

Answer 16

This theory tries to explain why organisms seem to suddenly disappear from existence on earth, such as the extinction of the dinosaurs. Some catastrophic event must have occurred to cause their sudden extinction to occur.

Question 17

What is the theory of uniformitarianism?

Answer 17

The theory tries to explain that the same geologic processes that are occurring today, also occurred in the past. Processes such as erosion or earthquakes.

Question 18

What’s the theory of gradualism?

Answer 18

This theory tries to explain that that the earth must be very, very old because in order for some processes to occur, such as mountain formation or canyon formation, it would require enormous amounts of time.

Question 19

What is absolute Radiometric dating?

Answer 19

Uses the half-life of radioactive elements that accumulate in an organism over time.

Question 20

What’s relative dating?

Answer 20

Uses the different strata of rock and index fossils to establish a time line.

Question 21

What are 4 major eras of time on earth?what are each known for?

Answer 21

Precambrian Era – The earth formed, cooled, oceans formed and then life began to appear.
Paleozoic Era – known as the age of fish, as they were the most common animal at the time. The first forest began to appear on land.
Mesozoic Era - know as the age of reptiles (Dinosaurs time).
Cenozoic Era – known as the age of mammals and includes right now.