biology
Study Guide
Introduction to Biology
Bunker Hill Community College Bio 105 Dr. Urbi Ghosh
1
Evolution
Chapter 18/19
1) What is evolution?
2) Evolution is: a. Fixed and in one direction b. Completely random c. Neither entirely fixed nor entirely random
3) What are the 5 factors that can lead to evolution?
1) 2) 3)
4)
5)
4) What is gene flow?
5) Complete the sentence: What is meant by an organism having a “high fitness” or being “the fittest” in evolution?
6) True or False? A horse and a donkey can produce a sterile mule; therefore, horses and donkeys are the same species. ______________ Explain your answer:
Study Guide
Introduction to Biology
Bunker Hill Community College Bio 105 Dr. Urbi Ghosh
2
7) Define the term natural selection.
8) What is the point of depicting animal species on a tree of life with branches?
a. To summarize the fossil record b. To describe how natural selection works c. To be a library of all of life that has ever lived d. To explain how all species are related to each other.
9) For a mutation to affect evolution, it must: a. Provide a benefit to the organism b. Involve more than one chromosome c. Be able to get passed from parent to offspring.
10) When you compare the DNA of two closely related organisms, would you expect their DNA to be more similar or less similar than the DNA of two distantly related organisms? Explain your answer.
11) Fossils almost never contain DNA, so how can we know how closely, or distantly related fossil organisms are to living organisms?
Study Guide
Introduction to Biology
Bunker Hill Community College Bio 105 Dr. Urbi Ghosh
3
12) What does the circled node (red) represent? a. The common ancestor species of A and B b. A speciation even c. Both A and B
13) Which way does the tree run? a. From root to branch tip b. Across branch tips, from left to right.
14) Which traits do A and B share? Which traits do B and C share? A and B: B and C:
Study Guide
Introduction to Biology
Bunker Hill Community College Bio 105 Dr. Urbi Ghosh
4
15) What are the two key ingredients for natural selection?
a. Reproduction and variation b. Predation and the environment c. Reproduction and predation d. The environment and variation.
16) Choose which type either VARIATION or ADAPTATION
a. __________The difference in the physical traits between organisms in a population.
b. __________ A feature that allows an organism to better survive in its c. environment. d. __________A turtle population lives in an area of tall grass. These
turtles have longer necked than turtles in other areas. Having a long neck is an example of this.
e. __________One fish in a population has slightly darker scales that its relatives. The difference in color of scales is an example of this.
17) Fill in the blanks:
Artificial selection is where certain traits are manipulated by __________, while natural selection ,___________________ is the selective agent.
Study Guide
Introduction to Biology
Bunker Hill Community College Bio 105 Dr. Urbi Ghosh
5
18) Natural selection explains how evolution can occur. Match the 4 main principles of natural selection with the correct definition: Terms
A. Overproduction B. Adaptation C. Descent with
modification D. Variation
Producing many offspring, some of which may not survive.
Heritable differences that make an individual unique.
An advantageous trait; one well suited for the environment
A heritable, advantageous, trait becoming more common in a population
19) Which statement is correct ? Circle one of the following: a. Natural selection acts on existing traits b. Natural selection works directly on DNA
• Define the term extinct.
• What are homologous structures?
• What are vestigial structures? List an example of a vestigial structure.
Study Guide
Introduction to Biology
Bunker Hill Community College Bio 105 Dr. Urbi Ghosh
6