GENETICS AND EVOLUTION

As a result of studying patterns of heredity and historical changes in life forms:

Students understand how each organism carries a set of instructions (genes composed of DNA) for specifying the components and functions of the organism.

• Describe how genetic materials are organized in genes and chromosomes in the cells of living organisms. (LIIA1)

1. What is the relationship between the three structures in the diagram above?

a. DNA is produced by protein which is produced in the cell.
b. Protein is composed of DNA which is produced in the cell.
c. DNA controls the production of protein in the cell.
d. A cell is composed only of DNA and protein.

2. A chromosome is best described as a

a. gene that has more than one form.
b. green cell found in many plants.
c. strand of DNA containing genetic information.
d. reproductive cell found in certain kinds of bacteria.

• Explain how the genetic information from both parents is mixed in the fertilized egg to produce an individual with new combinations of genes and traits. (LIIA2)

3. In fruit flies, gray body color (G) is dominant over black body color (g). What kind of offspring would you expect from parents who are both heterozygous for body color (Gg x Gg)?

a. 0% gray, 100% black
b. 25% gray, 75% black
c. 75% gray, 25% black
d. 100% gray, 0% black

4. Which statement about DNA is correct?

a. A child’s DNA will be unrelated to the mother’s or father’s DNA.
b. A child’s DNA will show similarities to both the mother’s and father’s DNA.
c. A female child’s DNA will exactly match the mother’s DNA.
d. A male child’s DNA will exactly match the father’s DNA.

5. Hair color in humans is an inherited trait. How is it possible for two people who hadbrown hair from birth to produce a child with blond hair?

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Before having children, couples may seek genetic counseling to find out if their babies will be at risk of inheriting genetically transmitted diseases.

Cystic fibrosis is a common hereditary disease that usually appears in early childhood. It involves glandular disorders and leads to problems with digestion and respiration. The recessive gene for cystic fibrosis may be represented by "n," with "N" representing the dominant allele for the normal trait. Only a person with two recessive genes (nn) will have cystic fibrosis. A person with a dominant gene (N) and a recessive gene (n) does not have the disease but has the potential to transmit it to his or her children. A person with the genotype Nn is frequently called "a carrier."

After having three healthy children, Martin and Jessica went to see a genetic counselor. The counselor tested the couple and found that both Martin and Jessica are heterozygous (Nn) for cystic fibrosis. This means that they do not have cystic fibrosis, but they could have a child with the disease.

Using the chart above, the counselor explained that the couple has a 25% chance (1 in 4) of having a child with cystic fibrosis.

Martin and Jessica were disappointed. They wanted to have another child, but since they already had three healthy children, they believed that a fourth child would almost surely have cystic fibrosis.

6. Do you agree with Martin and Jessica’s conclusion? Explain why you do or do not agree with their conclusion.

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• Explain how genes are related to inherited traits and how genes can be manipulated by modern technologies. (LIIA3)

7. What technological application from the 1990s was advanced by the discovery of the structure of DNA in the 1950s?

a. solar cells
b. computer viruses
c. the Internet
d. crime solving

While investigating applications of science knowledge, Willy learned that scientists have used genetic engineering techniques to attach insulin-producing genes to bacterial DNA.  These bacteria produce large amounts of scarce human hormones. Scientists predict that hormones produced by bacteria will be inexpensive and will not cause allergic reactions.

8. Scientists developed hormone-producing bacteria because they wanted to

a. learn about bacteria.
b. discover a cure for diseases.
c. find a way to increase the supply of hormones for use by humans.
d. compare the hormones produced by bacteria with hormones produced naturally.

Students understand that the basic idea of biological evolution is that the Earth’s present-day species developed from earlier species.

• Explain how environmental changes can lead to the extinction and evolution of species. (LIIB1)

9. Doctors need to be careful not to give their patients an antibiotic such as penicillin too often. If the same antibiotic is prescribed too many times, it can become less effective against bacteria. Explain fully why this is so.

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10. In the early days of antibiotic use, penicillin and sulfonamide were used to successfully treat a variety of bacterial infections. In later years, stronger antibiotics were needed because some bacteria were either resistant to or not affected by these same antibiotics.  This situation is best explained

a. by the lack of quality control in drug companies.
b. as the result of poor nutrition.
c. by doctors prescribing the wrong antibiotic.
d. by the process of natural selection.

When a population of mice is infected with parasites, many of the mice die from the parasitic infection, but some mice appear as healthy as they were before being infected.   Some people are considering using these parasites to control the mouse population in people’s homes.

11. Give one advantage and one disadvantage of using these parasites instead of mouse traps or poisons to limit the population of mice.

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• Describe how fossils and anatomical evidence provide support for the theory of evolution. (LIIB2)

In a section of the Grand Canyon, scientists have found the fossil remains of several different groups of organisms. The diagram below represents the number and age of the fossils the scientists found. The width of each shaded area in the diagram below indicates the relative number of fossils found.

12. Which of the following statements is supported by the fossil record?

a. Group C is now extinct.
b. Group D has been in existence the longest.
c. Group A is the most recent organism to come into existence.
d. Group B was the most numerous organism 10 million years ago.

13. Which of the following is usually most helpful in determining the age of these fossils?

a. the size of the fossils
b. the color of the fossils
c. the amount of surface area of the rock layer in which the fossils are found
d. the depth of the rock layer in which the fossils are found

14. The scientists hypothesize that the four groups of fossilized organisms originated from a common ancestor. Which of the following would provide the best evidence that their hypothesis is correct?

a. the number of fossils found in each group is similar.
b. present-day members of the groups live in the same environment.
c. fossils from each group were found in the same rock layer.
d. members of the groups have similar physical structures.

15. If an intestinal cell in a butterfly contains 24 chromosomes, a butterfly egg cell would contain

a. 3 chromosomes.
b. 6 chromosomes.
c. 12 chromosomes.
d. 24 chromosomes.