7th Grade Science - hart.k12.ky.us



7th Grade Science

Genetics Study Guide

3/24/14

1. Be able to tell the function of the following cell

2. Cytoplasm— organelles:

a. Mitochondria—produces the energy for the cell

b. Cell membrane—controls what comes in and out of the cell

c. Nucleus—the brain of the cell.

d. Cell wall—gives structure to a plant cell. The “bones” of a plant cell

e. Vacuole—storage unit for water and food

f. Chloroplast—where photosynthesis occurs in a plant cell

g. Chlorophyll—the green pigment responsible for absorbing sunlight for photosynthesis

h. Cytoplasm--- the jelly-like substance inside a cell that contains all the cell organelles

3. Be able to contrast asexual and sexual reproduction Asexual= 1 parent Sexual= 2 parents

4. Tell 2 advantages of asexual and 1 disadvantage of asexual reproductionAsexual= 1) do not have to wait for a mate 2.) makes more offspring

Disadvantage) if a mutation or problem occurs, since offspring are genetically identical, then the problem could cause a population to become extinct.

5. Tell 1 advantage and 1 disadvantage of sexual reproduction Sexual= Advantage) allows for better adaptation from changes in the environment, more variety Disadvantage) need to find a mate and takes longer to reproduce

6. Tell some examples of asexual reproduction and what each do:

a. Budding—offspring grow off of the parent (yeast)

b. Cell division (mitosis), (binary fission)—one cell divides into two (binary fission is in bacteria)

c. Regeneration—organism “grows” or regenerates offspring

7. Be able to contrast meiosis and mitosis and be able to tell what types of cells each process produces. Meiosis produces sex cells with ½ of chromosomes. Mitosis makes body cells with full number of chromosomes

8. Tell which process from #6 produces diploid and haploid cells. Meiosis produces haploid, mitosis produces diploid

9. Be able to know the definitions of the following terms:

a. Dipoloid—full # of chromosomes

b. Haploid—1/2 # of chromosomes

c. Sex cell—egg or sperm

d. Fertilization—egg + sperm

e. Egg—female sex cell

f. Sperm—male sex cell

10. Be able to tell that after meiosis occurs in an organism, what is the next process that must happen? fertilization

11. Be able to tell what cell organelle has the genetic material? nucleus

12. Know the definition of the following terms:

a. Chromosome—made from DNA contains genes

b. Gene—a section of a chromosome that contains a trait

c. Trait—a characteristic of an organism

d. Genetics—the study of the passing of traits

e. Heredity—the passing of traits from parents to offspring

f. DNA—the blueprint for life

13. Be able to tell the difference between genotype and phenotype. Genotype=the actual gene pairs from the parents Phenotype=the trait that is expressed or that you see.

14. Be able to define the following terms:

a. Heterozygous—two different genes

b. Homozygous—having two dominant or two recessive

c. Hybrid—another word for heterozygous

d. Purebred—another word for homozygous

e. Punnett square—tool used to predict outcomes of specific traits from parents to offspring

15. Be able to fill in a punnett square after being given an example of the parents.

16. Contrast a dominant (Occurs the most) and a recessive (occurs not as often) gene.

17. Be able to tell how many chromosomes humans have? 46 How many pairs is this?23

18. Why do all chromosomes from organisms that reproduce sexually occur in pairs? Because there are two parents. One chromosome comes from the mother and one comes from the father.

19. Be able to tell the chromosome combination for a boy and a girl: (these are called the SEX CHROMOSOMES because they determine gender)

a. Male—XY

b. female—XX

20. Be able to define these terms:

a. Allele—different forms of a gene (another word for a gene)

b. Homologous chromosomes—matching chromosomes

21. Be able to distinguish between a learned behavior and an inherited behavior. If given examples in a question, be able to tell if the behavior or trait is inherited or learned.

22. When given a problem in which you will need to make a punnett square, be able to tell the probability or percentage of the offspring that will show the dominant or recessive trait.

The test will consist of multiple choice questions and two open responses. Be prepared for a long assessment for this unit. Good Luck!!!!

Mrs. Jones

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