1.  A: Who first studied the process of mitosis?
     B: Why do cells need to do mitosis?
     C: Why wouldn’t mitosis be an acceptable method of reproducing offspring for humans?

2. Scientists have established that most cells follow a general life cycle called the cell cycle.
     A: Why do cells spend most of their lifetime in interphase?
     B: Generally speaking, both mitosis and cytokinesis are involved in doing what to the cell?

3. Walter Sutton is credited with explaining the process of meiosis.
     A How did Sutton study meiosis?
     B: While studying meiosis, Sutton also read Mendel’s work. What connection did Sutton make between his
          work on meiosis and one of Mendel’s principles?

4. Meiosis is a specialized type of cell division common to many living things on earth.
     A: Is meiosis found in organisms that utilize sexual reproduction, asexual reproduction, or both?         
          Explain your answer.
     B: How are cells produced by meiosis different than cells produced by mitosis?
     C: Are the products of meiosis the same for males and females?                Explain.
     D: Meiosis is often described as a double division. This is necessary because during meiosis the cell must
          reduce both its ………………. and ……………….. of chromosomes.

5. Why are scientists allowed to do almost unlimited types and numbers of research projects on somatic cells,
     while numerous laws exist to restrict research on germ cells?

6. Match the following genetic discoveries of Thomas Morgan with their descriptions and/or examples.
      (Note -> Use A, B, C, & D to answer. Answers can be used more than once.)
     A: sex-linkage                 1: occurs to tetrads during meiosis I
     B: linkage groups             2: defines the X as the female & Y as the male chromosomes
     C: sex determination        3: says that genes on same chromosomes can be inherited together
     D: crossing over              4: says some traits are always associated with 1 sex
                                           5: an example in humans is blue eyes with blond hair
                                           6: mixes genes, thus blue eyes might appear with brown hair
                                           7: was discovered using fruit flies

7. Mutations can occur as either micromutations or macromutations.
     A: (TRUE OR FALSE) All mutagens known to scientists today are man-made.
     B: Why do macromutations often have far stronger and more wide ranging effects on an organism that
           micromutations?
     C: Would a mutation in a body cell have the same results on an individual as a mutation in a germ cell?
          Explain.
     D: Are all mutations that occur in a population of animals bad for that population?                Explain.

8. Nondisjunction occurs when a replicated pair of chromosomes fails to separate.
     A: Does nondisjunction only occur with sex chromosomes?
     B: Does nondisjunction always lead to the death of the cell (and the individual)?                Explain.
     C: (TRUE OR FALSE) Nondisjunction only occurs in males.
     D: Should a nondisjuction to cause a small or a large change in an individual?                Explain.

9. Mutagens such as smoke tend to induce more somatic mutations than germ cell mutations. Radiation on the
     other hand tends to induce more germ cell mutations than somatic. Why then do federal scientists and
     federal regulations worry more about radiation levels in our communities than smoke levels in our homes?

CRITICAL THINKING:
10. Cancer is when body cells divide uncontrollably. Why then have cancer researchers spent so much time
      studying the process of mitosis?

11. A clone is an exact duplicate of another living thing.
     A: Is it theoretically possible to clone another human using a single skin cell from your body?
          EXPLAIN.
     B: Is it theoretically possible to clone another human using a single egg or sperm from your body?
          EXPLAIN.

12. Nerve cells are the only cells in the human body that never finish the cell cycle. Today it is known that nerve
     cells stay in interphase for their entire lives. How does this change the behavior/abilities of nerve cells?

13. If an organism normally has 36 chromosomes, how many chromosomes would each new cell have:
     A: after mitosis is done?                     B: after meiosis I is done?                     C: after meiosis II is done?

14. Humans have 46 chromosomes in every body cell. Scientists often say we have 22 PAIR of
     homologous (“like”) chromosomes because they carry the same traits (making them the same size
     and shape). The last pair of chromosomes are the sex chromosomes: XX for female and XY for male.
     A: Which sex “could” be said to have 23 pair of homologous chromosomes?                Explain.
     B: The male makes two types of sperm depending on the sex chromosome it contains: “X” (girl) and
          “Y” (boy).
               1: Which type of sperm is lighter in weight?
               2: Are more female or male zygotes conceived in humans?
     C: Do each sperm a man makes receive the exact same autosomes?

15. State whether the following are describing mitosis or meiosis, or both.
     A: Process allows a skin wound to heal.
     B: Mistakes in process can be a major source of genetic disorders.
     C: Process requires a double division to complete
     D: Process provides a tool for mixing genetic information in a population
     E: Process and final products different for each sex
     F: Process does NOT require homologous chromosomes to pair up before duplicating
     G Process contains phases called Prophase, Metaphase, Anaphase, and Telophase

16. Crossing-over is a natural event that occurs when chromosomes are closely packed together as tetrads
     during meiosis. Commonly these chromosomes lie across each other and exchange fragments (genes).
     Generally speaking, does this crossing-over:
     A: require the two chromosomes to touch each other or just be near each other?
     B: occur when an animal utilizes asexual reproduction?                EXPLAIN.
     C: increase or decrease variety in a species?                EXPLAIN.

EXTRA CREDIT:
17. According to two of Mendel’s principles; “Principle of Segregation” and “Principle of Independent
     Assortment”, two brothers or sisters born 3 years apart cannot be identical twins.
     A: Use these two principles to explain why identical twins, 3 years apart, should be impossible?
     B: Use the following information to mathematically calculate the odds of the above ever happening.
          First consider the number of genetic types of sperm or eggs one parent can produce.
               If 1 pair of homologous chromosomes -> yields 2 genetically different types of sperm or eggs :
                      (Example : Tt --> T + t)
               If two pairs of homologous chromosomes can yield 4 genetically different types of sperm or eggs:
                      (Exampe : TtRr --> TR + Tr + tR + tr)
               If three pairs of homologous chromosomes can yield 8 genetically different types of sperm or eggs:
                      (Example : TtRrYy --> TRY + TRy + Try + tRY + trY + tRy + TrY + try)
          Then, how many different types of sperm or eggs can 23 pairs of homologous chromosomes produce?
                     (Express answer as a fraction: "1/x", meaning 1 out of X number of births)