ALPF Medical Research

Meiosis In Grasshopper Testis

uSING vOCABULARY

1. For each pair of terms, explain how the meanings of the terms differ.

a. autosome and sex chromosome b. synapsis and crossing-over c. haploid and diploid

2. Explain the relationship between the terms chromosome and homologous chromosomes.

3. Use the following terms in the same sentence: mitosis, meiosis, and cytokinesis.

4. Word Roots and Origins The word oogenesis is derived from the Greek oion, which means "egg," and geneia, which means "birth." Using this information, explain why the term oogenesis is a good name for the biological process it describes.

Understanding Key Concepts

5. Describe the structure of a chromosome.

6. Compare prokaryotic chromosomes with eukary-otic chromosomes.

7. State the number of chromosomes in normal human cells.

8. Identify the type of chromosome that determines the sex of an organism.

9. Distinguish between haploid cells and diploid cells.

10. Define the term binary fission. In what type of organism does this type of cell division occur?

11. Differentiate mitosis from cytokinesis.

12. Describe the events that occur in the G0, Gj, and G2 phases.

13. Summarize the phases of mitosis.

14. Describe the process of cytokinesis in plant cells.

15. List the three main checkpoints at which the cell cycle is controlled.

16. Identify the type of nuclear division that results in haploid cells.

17. Compare the phases of meiosis I with those of meiosis II.

18. Name the meiotic process that results in genetic recombination.

19. Summarize the major characteristics of spermato-genesis and oogenesis.

20. Identify the relationship between sexual reproduction and genetic variation.

21. Unit 4—Cell Reproduction

^¡«m^ Write a report summarizing how ttOLOCI « different cancer-fighting drugs kill cancer cells by interrupting the events of the cell cycle.

22. CONCEPT MAPPING Use the following □ □ □ terms to create a concept map that shows the connection between cellular division in prokaryotes and eukaryotes: binary fission, cell cycle, cytokinesis, eukaryote, mitosis, and prokaryote.

Critical Thinking

23. Predicting Results Can mitosis occur in the absence of cytokinesis? Support your answer. If your answer is yes, describe how the new cell would appear in the G1 phase.

24. Making Calculations If you consider the mass of DNA in a sperm (a haploid cell) to be 1, what would the relative value be for the DNA mass of a cell in the G2 phase of the cell cycle?

25. Applying Information Does a cell in metaphase II have the same mass of DNA as a diploid cell in the G1 phase? Assume that both cells are from the same animal. Explain your answer.

26. Analyzing Information The events of mitosis in plants and animals are very similar, with the exception of the absence of centrioles in plants. How has the absence of centrioles in plant cells influenced scientists' thinking about the function of centrioles in mitosis?

27. Interpreting Graphics The photograph below shows cell division in a grasshopper testis. The offspring cells are gametes. Do you think the photograph shows mitosis or meiosis? Explain your answer.

Ms/ Standardized Test Preparation

DIRECTIONS: Choose the letter of the answer choice that best answers the question.

1. Which of the following statements about prokary-otic chromosomes is true?

A. Prokaryotes have at least two chromosomes.

B. Prokaryotic chromosomes consist of a circular DNA molecule.

C. Prokaryotic chromosomes include histone and nonhistone proteins.

D. Prokaryotic chromosomes are made of DNA wrapped tightly around histone proteins.

2. Crossing-over occurs during which process?

F. mitosis

G. meiosis I

H. meiosis II J. interphase

INTERPRETING GRAPHICS: The graph below shows the relative mass of DNA and chromosome number for a cell undergoing mitosis. Use the graph to answer the questions that follow.

Mitosis