Basic Genetics Study Guide

I-Matching On the lines provided, write the letter of the definition of each term.

1. genetics a. likelihood that something will happen

2. traitb. process of reduction division

3. hybrid c. specific characteristic

4. gene d. produced by crossing parents with different

alleles

5. allele e. containing a single set of chromosomes

6. gamete f. reproductive cell

7. probability g. factor that controls traits

8. Punnett square h. diagram showing possible gene combinations

9. haploid i. branch of biology that studies heredity

10.meiosisj. form of a gene

II- Define the following and show with an example (letters/pictures)

1-Dominant:

2-Recessive

3- Homozygous

4- Heterozygous

5- Crossover

6- Incomplete dominance

7- Codominance

8- sex linked inheritance

III- Fill in the blank or circle the correct word choice

1- According to the principle known as ______genes that segregate independently do not influence each other’sinheritance.

2-______results in the exchange of alleles and

produces new combinations of alleles.

Circle the correct answer.

3- The separation of alleles is called

segregation. meiosis. true-breeding. crossing-over.

4-Organisms that have identical alleles for a particular

trait are

heterozygous. diploid polygenic. homozygous.

5-An organism that has an allele for brown eyes and anallele for blue eyes is

true-breeding. heterozygous. homologous. homozygous.

6-The genetic makeup of an organism is its

genotype. genetics. meiosis. crossing-over.

Draw a diagram crossover and describe the importance of it.

Solve the following genetics problems: Use the alleles as stated below.

Tall (T) / Round seed (R) / Inflated pod (I) / Green Leaf (G) / Long stem (L)
Short (t) / Wrinkled seed (r) / Wrinkled pod (i) / Yellow Leaf (g) / Short stem (l)
  1. Cross a heterozygous long stem plant with a short stem plant.

What is the resulting genotype ratio?

What is the resulting phenotype ratio?

2. Cross two heterozygous round, heterozygous green leaf plants.

What are the parent’s genotypes?

How many of the offspring will be round and yellow?

  1. A woman who is a carrier for hemophilia marries a hemophiliac man. (This is a sex-linked disorder)

What will the phenotypes of their male children be?

  1. Colors of wheat kernels range from white (WW) to dark red (RR) with various shades of pink (WR) in between. Cross two pink plants.

What are the genotypes of the F1 offspring?

  1. By what pattern of inheritance is the trait from question #4 controlled; meaning what type of dominance is exhibited?
  1. A man Type O blood marries a woman with blood type AB. What are the genotypes of their future children?
  1. On what types of plants did Mendel do his hereditary experiments?
  2. What is a Punnett Square and why is it used?
  3. Use the following information to explain Mendel’s Law of Independent Assortment.
  1. Examine the following Punnett Square:

T t

TT / Tt
TT / Tt
  1. What must the genotype for the second parent be?
  2. What do the letters inside the boxes represent (be specific)?
  1. Why is it that a male child is more likely to inherit a sex-linked disorder, such as colorblindness than is his sister?
  1. In summer squash, white fruit color (W) is dominant over yellow fruit color (w) and disk-shaped fruit (D) is dominant over sphere-shaped fruit (d). If two squash plant heterozygous for white, disk-shaped fruitare crossed, complete the following:

a-Write the genotypes for both parents______X ______

b-Write out the 8 allelic combinations for each parent

  1. What should be the phenotypic ratio of dihybrid cross between two parents both, if placed on the dihybrid punnett square : 9:____:____:______

Pedigree - USING SCIENCE SKILLS

The pedigree shows the inheritance of free earlobes (F) and attached earlobes (f) in five generations of a family. Attached earlobes are caused by a recessive allele (f). Half-shaded symbols are NOT used in this pedigree to show carriers of the allele.

Figure 14-2

17. Inferring Is individual 1 in Figure 14-2 homozygous or heterozygous for free earlobes? Explain.

18. Interpreting Graphics In Figure 14-2, how many children of individuals 4 and 5 have free earlobes?

19 Inferring Can you be certain of the genotype of individual 3 in Figure 14-2? Explain. What about 5?

20. Predicting Predict the genotype and phenotype of individual 14 in Figure 14-2.

21. Inferring In Figure 14-2, are any of the descendants of individuals 1 and 2 homozygous for free earlobes?

Blast from the Past- KNOW THESE CONCEPTS !!

  • Three types of symbiotic relationships
  • Levels of ecological organization- large to small
  • Organization of organisms on ecological pyramid. Where is most/least biomass?
  • Biotic vs abiotic factors that influence an ecosystem
  • Does energy flow or cycle? What nutrients in ecosystems cycle?