1. Meiosis & Sexual Reproduction
Chapter 6 Review

2. What is the haploid number? What is the diploid number?
The number of pairs of inherited chromosomes.
Half the diploid number. n
Diploid number
The number of two sets of chromosomes. 2n

3. What is the diploid number for a human? What is the haploid number?

4. What is a gamete. What is a zygote. What is an embryo
What is a gamete? What is a zygote? What is an embryo? What is fertilization?
Gamete: specialized cells for reproduction (sperm and egg cells)
Zygote: diploid cell made from fertilization when two gametes join together
Embryo: Multicellular organism that develops from a zygote
Fertilization: Process where a sperm and egg cell join and the haploid genetic information combines

5. Describe briefly what occurs during meiosis I.
The cell prepares to divide by replicating DNA.
The DNA crosses over to make variation in the genetic code.
Pairs of homologous chromosomes line up at the equator then are pulled to opposite poles.
The cell divides into two daughter cells, each with one set of the homologous chromosomes.

6. Briefly describe what occurs during meiosis II.
DNA is not replicated.
The chromosomes line up at the equator and then are pulled to opposite poles.
Produces 4 haploid daughter cells that has one set of chromatids (in humans that is 23 chromosomes)

7. What are the differences between meiosis I and II?
Pair of chromosomes line up at the equator
DNA is replicated before the process.
Produces diploid cells.
Meiosis II:
One set of chromosomes line up at the equator
DNA is not replicated beforehand.
Produces haploid cells.

8. What are homologous chromosomes?
A pair of matching chromosomes, one from each parent, that line up at the equator during meiosis I.

9. Describe two ways that meiosis produces genetic diversity.
Crossing over:
During meiosis I, each homologous chromosome pair exchange segments of DNA so each chromosome has new genetic information.
Independent assortment:
When homologous chromosomes line up at the equator, there are two possibilities for how each pair will be pulled to opposite poles. This means that each daughter cell can have some chromosomes from each parent.

10. What is the difference between meiosis and mitosis?
Mitosis involves only one stage, meiosis has I and II.
Mitosis produces two diploid daughter cells, meiosis produces four haploid daughter cells.
Mitosis needs only one parent, meiosis needs two parents.
Mitosis does not produce genetic diversity, meiosis does.

11. Which cells in your body are made using mitosis
Which cells in your body are made using mitosis? Which are made using meiosis?
Meiosis: your sex cells (sperm and egg cells)
Mitosis: all other cells (skin, lungs, kidney, etc)

12. What are the four types of chromosome mutations?
Inverted
Duplicated
Deleted
Moved

13. What is the difference between a gene mutation and a chromosome mutation?
A gene mutation involves a change of only one base in the DNA, a chromosome mutation involves a change in a whole section of the chromosome.

14. What is a karyotype?
A picture that shows the number of chromosomes a person has, their size and shape
Used to diagnose genetic disorders

15. What is sexual reproduction?
Reproduction that requires two parents and makes offspring that are genetically different from each other and either parent.

16. What is external fertilization? What are its advantages? Disadvantages?
External fertilization: fertilization that occurs outside the bodies of the parents.
Advantages:
Little energy required to find mate
Greater numbers of offspring
Genetically different offspring
Disadvantages:
Offspring are unprotected and can be preyed upon

17. What is internal fertilization? What are its advantages? Disadvantages?
Internal fertilization: Fertilization that occurs inside the body of the parent.
Advantages:
More protection from predators
More parental care
Genetically different offspring
Disadvantages:
More energy required
Fewer offspring produced

18. Name one type of Assisted Reproductive Technology.
Possible answers:
Artificial Insemination (AI)
In Vitro Fertilization (IVF)
Gamete Intrafallopian Transfer (GIFT)
Intracytoplasmic Sperm Injection (ICSI)

19. What is the correct order for sexual reproduction using the following words? Embryo, gamete, fertilization, meiosis
Meiosis  gamete  fertilization  embryo