Download How does genetic variation lead to evolution?

Unit 6: Evolution
Name: _______________________________________
Aim #44 Variation: What are some sources of genetic variation in a population?
Date: __________________
How does genetic variation lead to evolution?
Directions: Read “Aim 44: Sources of Genetic Variation Reading” pages (1 and 2) and answer the following questions.
I.
Pg. 1: Sources of Variation (How do organisms vary from their parents?)
1.
What determines all the inherited characteristics of an individual?
2.
The genes of which type of cells get passed on to the offspring? ____________ cells
3.
So, does a father who has built huge muscles (muscle cells), due to exercise, pass on those large muscles to his offspring?
Explain why or why not (refer to your answer for # 2).
4.
How can an organism wind up with genes that differ from those of its parents? Explain both reasons why this can occur.
II.
Pg. 1: Mutation (How do mutations affect individuals?)
5.
Define mutation:
6.
Which type of cell does a mutation have to occur in to only affect that individual and not his/her offspring? ___________ cell
7.
In sexually reproducing organisms, only changes in the genes of ________ cells can be passed to the next
__________________________________ and the basis for _____________________ ___________________________.
III.
8.
Can mutations be positive, negative, or both. _________________________________
9.
Provide an example of a mutation and explain why the mutation is positive or negative.
Pg. 1: Genetic Shuffling
10. Why do siblings (if you have any) all look different?
11. Explain why sexual reproduction is similar to shuffling two decks of cards?
IV.
Pg. 1: The Results of Genetic Variation
12. Identify the three types of variation (changes) within a species that can lead to evolution?
____________________,
______________________________,
________________________
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V.
Pg. 2: Structural Change
13. Describe an example of a structural change in an animal that led to evolution? Why was this change beneficial?
14. Now that you have learned about an example of a structural change, explain what a structural change is.
VI.
Pg. 2: Functional Change
15. Describe an example of a functional change in an animal that led to evolution? Why was this change beneficial?
16. Now that you have learned about an example of a functional change, explain what a functional change is.
VII.
Pg. 2: Behavioral Change
17. Describe an example of a behavioral change in an animal that led to evolution? Why was this change beneficial?
18. Now that you have learned about an example of a behavioral change, explain what a behavioral change is.
VIII.
Pg. 2: The Importance of Variation
19 If environmental changes occur, what could happen?
20. Why is it better to have variation within a species instead of every individual being the same?
21. Why are scientists concerned about endangered species?
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22. Which statement is basic to the theory of evolution by
natural selection?
a. In general, living organisms maintain a constant
population from generation to generation
b. Changes in living organisms are almost
completely the result of mutations
c. Natural variations are inherited
d. There is little competition between species
28. Which two factors provide the genetic basis for variation
within many species?
a. Asexual reproduction and meiosis
b. Mutations and sexual reproduction
c. Competition and the synthesis of proteins
d. Ecological succession and mitosis
23. Which statement is not included as part of our modern
understanding of evolution?
a. Sexual reproduction and mutations provide
variation among offspring
b. Traits are transmitted by genes and chromosomes
c. More offspring are produced than can possibly
survive
d. New organs are formed when organisms need
them
29. Which statement best describes a current understanding of
natural selection?
a. Natural selection influences the frequency of an
adaptation in a population
b. Natural selection has been discarded as an
important concept in evolution
c. Changes in gene frequencies due to natural
selection have little effect on the evolution of
species
d. New mutations of genetic material are due to
natural selection
24. A new chemical was discovered and introduced into a
culture containing one species of bacteria. Within a day,
most of the bacteria were dead, but a few remained alive.
Which statement best explains why some of the bacteria
survived?
a. They had a genetic variation that gave them
resistance to the chemical
b. They were exposed to the chemical long enough
to develop a resistance to it
c. They mutated and became a different species after
exposure to the chemical
d. They absorbed the chemical and broke it down in
their digestive systems
30. The Florida panther, a member of the cat family, has a
population of fewer than 100 individuals and has limited
genetic variation. Which inference based on this information
is valid?
a. These animals will begin to evolve rapidly
b. Overtime, these animals will become less likely
to survive in a changing environment
c. These animals are easily able to adapt to the
environment
d. Over time, these animals will become more
likely to be resistant to disease
25. Sexual reproduction is related to evolution because sexual
reproduction
a. Occurs only in more recently evolved forms of
animal life
b. Increases the chances of extinction of different
species
c. Increases the chances for variations to occur
d. Is the more usual kind of reproduction
31. Which statement could be used as evidence to show that two
different species of organisms most likely developed forma
single common ancestor?
a. They eat the same types of food
b. They have different digestive enzymes
c. They have similar amino acid sequences
d. They lived during the same time period
26. Mutations can be transmitted to the next generation if they
are present in
a. Hormones
b. Gametes
c. Body cells
d. Muscle cells
32. In most populations, the individuals that produce the greatest
number of offspring are
a. Always the strongest
b. Usually the best adapted
c. Those that have only inheritable traits
d. Those that are the most intelligent
27. Which characteristic of a population would most likely
indicate the lowest potential for evolutionary change in
that population?
a. Sexual reproduction and few mutations
b. Sexual reproduction and many mutations
c. Asexual reproduction and few mutations
d. Asexual reproductions and many mutations
33. The modern theory of evolution states that a basis for
variation within a species is provided by
a. Mutations
b. Asexual reproduction
c. Cloning
d. Overproduction
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Aim 44: Sources of Genetic Variation Reading
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