week 1 (intro + transmission gen.)

Question 1

recap: historical overview of genetics

Answer 1

1900
- 3 botanists replicate Mendel’s results

1909
- Morgan rediscovers Mendel’s laws w/ flies

1911
- white eye phenotype in fruit flies discovered and sex linked

1915
- first genetic map made w/ fruit flies

1944
- discovery of DNA as hereditary material

1953
- struc. of DNA by Watson and Crick

1960
- DNA transcription, mRNA translation, genetic code

1970
- first virus genome sequenced

1990s
- E.coli genome sequenced

2000
- fruit fly genome sequenced

2001
- human genome sequenced

Question 2

question: what direction are DNA strands read in?

Answer 2

5’ - 3’

Question 3

question: difference between transcription and translation?

Answer 3

• transcription: one strand DNA directs synthesis of single stranded RNA
• translation: converting genetic message carried by mRNA into AA seq.

Question 4

question: what are the start and stop codons?

Answer 4

START
AUG

STOP
UAA
UAG
UGA

Question 5

question: what phenotypic and genotypic ratio did mendel find by crossing 2 heterozygous seeds?

Answer 5

phenotypic = 3:1
genotypic = 1:2:1

Question 6

question: what is mendel’s first law?

Answer 6

• law of segregation
• each allele has equal probability of being passed on bc alleles segregate independently

Question 7

question: what is mendel’s second law?

Answer 7

• law of independent assortment
• segregation of alleles at one gene is independent of segregation of alleles at another gene

Question 8

question: what is the ratio from mendel’s dihybrid cross?

Answer 8

9:3:3:1

Question 9

summarize: results from testing mendelian hypotheses (phenotypic ratios for testing 1 gene, 2 genes)

Answer 9

ONE GENE
- Aa x Aa = 3:1
- Aa x aa = 1:1

TWO GENES
- AaBb x AaBb = 9:3:3:1
- AaBb x aabb = 1:1:1:1

Question 10

question: what does a high p value mean >0.05)?

Answer 10

• differences are not significant, cannot reject null hypothesis (cannot reject mendelian)