BIOL1102 Lecture Notes - Lecture 23: Metaphase, Gamete, Dwarfism

A professor asks you to help perform a Mendel-type pea plant experiment. She wants to see how independent some of the traits that Mendel inspected really are. To get started, she tells you she did a test cross and shows you a greenhouse full of F1 pea plants. She asks you to continue her experiment while she has to attend a scientific meeting in Europe, and to cross the F1's to generate F2 offspring. You do this with the help of the professors graduate students and get 3044 plants (wow, you guys did a lot of work!). Mendel looked at seven pea plant traits (https://en.wikipedia.org/wiki/Gregor_Mendel): seed shape, flower color, seed coat tint, pod shape, unripe pod color, flower location, and plant height. If Mendelian inheritance were true, how many plants would you roughly expect to be phenotypically recessive in seed shape, pod shape and plant height, but genetically heterozygous in the other traits? Enter an integer number (round up).

Mendel also did experiments with the flowering plant ‘Four-O-Clocks’. In this plant, yellow flowers are dominant to white flowers. When a certain yellow-flowered plant was self-pollinated, its progeny consisted of 77 yellowand 25 white-flowered plants. What was the genotype of the original yellow-flowered parent?

*I know the answer is Yy, however, why couldn't the answer be YY or Yy?

1:What is the principle ofsegregation? Why is it important?

2:What is the principle ofindependent assortment? How is it related to theprinciple

of segregation

3:How are Mendel%u2019sprinciples different from the concept of blendinginheritance?

4:What is the concept of dominance? How does dominance differfrom incomplete

dominance

5:What is the chromosometheory of inheritance? Why was it important?

6:Distinguish among the following terms: locus, allele,genotype, and phenotype.

7:How did Mendel know that each of his pea plants carried twoalleles encoding a

characteristic?

8:How do incompletedominance and codominance differ?

9:What is incompletepenetrance and what causes it

10:What is geneinteraction? What is the difference between an epistatic gene anda

hypostaticgene?

11:What is a recessiveepistatic gene?

12:What characteristics are exhibited by a cytoplasmicallyinherited trait?

13:What is genomic imprinting?

14:What is the differencebetween genetic maternal effect and genomic imprinting?

15:What is the difference between a sex-influenced gene and agene that exhibits

genomicimprinting