Practice Questions

1. Sequence the following steps: scientific law, problem, theory, hypothesis, experiment.

2. Arrange each of the following in order from largest to smallest.
1. centimeter
2. kilometers
3. meters
4. micrometers
5. millimeters

3. A living cell has certain characteristics in common with a working factory. In a factory, products are assembled according to specified plans, energy is used in the assembly process, products are packaged and taken out of the factory, and a supervisor directs and oversees all of the activities occurring in the factory. Draw a model of a factory, labeling areas where the following important activities would occur: main office where supervisor keeps the plans and oversees activities, assembly line, electricity generator, packaging center, and factory doors. Next to each of your labels, write the name of the cellular organelle or structure that has a similar function. Choose the cellular organelles and structures from the list that follows: nucleus, cytoplasm, cell membrane, mitochondrion, endoplasmic reticulum, Golgi apparatus, vacuole. Write your answer in the space below.

4. A cell with a well-defined nucleus surrounded by a nuclear membrane is called a(n) ____________________ cell.

5. The fluid portion of the cytoplasm is called the ____________________.

6. Photosynthesis takes place in the ____________________ of plant cells.

7. Both plant and animal cells have cell membranes. In addition, plant cells are surrounded by a(n) ____________________.

8. ____________________ is a biochemical pathway of cellular respiration that is anaerobic.

9. A picture of a cell’s chromosomes is called a ____________________.

10. ____________________ is the process by which bacteria split asexually into two identical organisms.

11. In bacteria, cell division takes place in two stages. First the ____________________ is copied, and then the cell splits.

12. In mitosis, anaphase follows ____________________.

13. After a new nuclear membrane forms during telophase of mitosis or meiosis, the ____________________ divides, resulting in two cells.

14. The process called ____________________ guarantees that the number of chromosomes in gametes is half the number of chromosomes in body cells.

15. The cells resulting from meiosis in either males or females are called ____________________.

16. ____________________ refers to the transmission of traits from parent to offspring in sexually reproducing organisms.

17. An organism that has two identical alleles for a trait is called ____________________.

18. The likelihood that a specific event will occur is called ____________________.

19. A phenomenon in which a heterozygous individual has a phenotype that is intermediate between the phenotypes of its two homozygous parents is called ____________________.

20. Watson and Crick determined that DNA molecules have the shape of a(n) ____________________.

21. Due to the strict pairing of nitrogen base pairs in DNA molecules, the two strands are said to be ____________________ to each other.

22. According to base-pairing rules, adenine pairs with ____________________ and guanine pairs with ____________________.

23. Enzymes called ____________________ are responsible for unwinding the DNA double helix by breaking the hydrogen bonds that hold the complementary strands together.

24. The process by which DNA copies itself is called ____________________.

25. The information contained in a molecule of messenger RNA is used to make protein during the process of ____________________.

26. The process used to isolate a gene from the DNA of one organism and transfer the gene into the DNA of another is called ____________________.

27. Enzymes that cleave DNA at specific sequences, generating a set of small fragments of DNA, are called ____________________.

28. A large number of genetically identical cells grown from a single cell are called ____________________.

29. A species that has disappeared permanently is said to be ____________________.

30. A change in species over time is called ____________________.

31. The process by which organisms with traits well suited to an environment survive and reproduce at a greater rate than organisms less suited for that environment is called ____________________.

32. A(n) ____________________ consists of all the individuals of a particular species in a particular place.

33. ____________________ structures are similar because they originated in a shared ancestor.

34. List three practical uses of PCR. Write your answer in the space below.

35. Why has there been a burst of evolution after each of the great mass extinctions?

36. What role does the environment play in natural selection?

Answer Section for Practice Problems

1. problem, hypothesis, experiment, theory, scientific law

2. 2, 3, 1, 5, 4

3. main office—nucleus

assembly line—endoplasmic reticulum

electricity generator—mitochondrion

packaging center—Golgi apparatus

factory doors—cell membrane

4. eukaryotic

5. cytosol

6. chloroplasts

7. cell wall

8. Glycolysis

9. karyotype

10. Binary fission

11. DNA

12. metaphase

13. cytoplasm

14. meiosis

15. gametes

16. Heredity

17. homozygous

18. probability

19. incomplete dominance

20. double helix

21. complementary

22. thymine, cytosine

23. helicases

24. replication

25. translation

26. genetic engineering

27. restriction enzymes

28. clones

29. extinct

30. evolution

31. natural selection

32. population

33. Homologous

34. Answers include that PCR can be used to make DNA fingerprints from small samples found at a crime scene, to diagnose genetic disorders from a few embryonic cells, and to study ancient fragments of DNA found in minute amounts.

35. The organisms that survive the mass extinctions find themselves in a world of opportunity—an Earth full of food and space that is no longer used by others.

36. According to Darwin’s theory, those organisms that have traits best suited to the environment most successfully survive and reproduce.