Mendelian Genetics

Mendelian Genetics

Name _________________________

Total points = 119

Your grade = your score/119

1. Define genetics and heredity. 2 points
2. What was Gregor Mendel’s contribution to Science? 2 points
3. What were the advantages of using the pea plant for Genetic research? 6 points
4. What were the 7 traits that Mendel selected for further study? 7 points
5. Mendel’s experiments had three features that represented improvements over previous experiments involving genetic crosses. What were they?  6 points
6. Explain the technique that Mendel used to perform a monohybrid genetic cross using the flower of a pea plant that had yellow seeds with the flower of a pea plant that had green seeds. What were the offspring from such a cross called?  4 points
7. Explain the terms dominant and recessive. 4 points
8. Explain the terms phenotype and genotype. 4 points
9. Define the terms gene, allele. 4 points
10. Define the terms homozygous, heterozygous. 4 points
11. State Mendel’s Law of Segregation. 2 points
12. Perform a genetic cross of pea plants with purple flowers with pea plants with white flowers. Use W for the purple trait, and w for the white trait.  Show the results for the F1 and F2 generation.  10 points

P1

F1

13. What is the phenotypic ratio for this cross? The genotypic ratio?  4 points
14. What is a test cross? 2 points
15. Perform a test cross of pea plants with purple flowers with pea plants with white flowers. Use W for the purple trait, and w for the white trait.  20 points

Using the example of a cross of pea plants with purple flowers with pea plants with white flowers, let’s assume the parent chosen from the F2 generation of plants with the yellow-seeded phenotype was homozygous (WW).  The test cross would be:

WW  X  ww

All of the individuals resulting from the cross of an individual homozygous for purple flowers with an individual that is homozygous recessive (white-flowered) will appear ____________________.  The parent with the unknown genotype was ________.

Now consider the cross in which a heterozygous individual is chosen by chance and used for the cross:

Ww  X  ww

In this case there are two ____________________ individuals and two ____________________ individuals, a ratio of 1 ____________________ to 1 ____________________.  The parent with the unknown genotype was ________.

16. What is a dihybrid cross? 2 points
17. State the Principle of Independent Assortment. 2 points
18. Perform a dihybrid cross using the following example. In guinea pigs, the allele for black fur B is dominant over the allele for brown fur b.  The allele for short hair S is dominant for the allele for long hair s. 20 points

P1                                   BBSS  X  bbss

F1                                          BbSs

What is the phenotypic ratio from this cross?

19. What is incomplete dominance? 2 points
20. Define the term mutation. Compare chromosomal mutations to point mutations.  Define gene deletion, duplication, inversion, and translocation.  12 points