Lecture 1 (Ch 1)

Question 1

What is a phenotype? A genotype?

Answer 1

Phenotype is the observable trait; Genotype is the genetic constitution of an organism

Question 2

What is an allele? A gene? Their relationship?

Answer 2

Allele is a variant form of a gene; Gene is a physical unit of heredity; Gene’s variations are called allele

Question 3

What is a chromosome? Its relationship with a gene?

Answer 3

Chromosome is a long molecule of double-stranded DNA and protein; parts of this double-stranded DNA within the chromosome are genes

Question 4

Griffith experiment found ___. What were four conditions?

Answer 4

A hereditary molecule is able to transform Rii to Siii. Living Siii; dead Siii; Living Rii, and living Rii+Dead Siii.

Question 5

Avery, MacLeod, and McCarty experiment found ___. What were the conditions? What kind of experiment was it?

Answer 5

DNA was the hereditary molecule that transformed Rii to Siii; dead Siii extract + enzymes that eliminated one molecule of life + live Rii; only DNAse produced live rat; negative experiment

Question 6

What are the components of a nucleotide?

Answer 6

5-carbon sugar (deoxyribose) with 3’ -OH and 5’ PO4 group, and 1’ nitrogenous base

Question 7

Watson and Crick described the structure of the DNA as

Answer 7

a double helix with sugar phosphate backbone in the outside and nucleotide bases in complementary pairs towards the center

Question 8

What is the bond between nucleotides?

Answer 8

phosphodiester bond between 3’ OH and 5’ PO4

Question 9

Which experiment suggested a double helix rather than a straight ladder?

Answer 9

Rosalind Franklin’s x-ray crystallography

Question 10

The experiment that suggested complementary base pairing was ___; in that experiment, it was found that ___

Answer 10

Chargaff’s analysis of the ratio of nucleotide bases; A/T = 1, and C/G = 1

Question 11

Strand polarity is established with ___

Answer 11

5’ PO4 group and 3’ OH group

Question 12

The strands must be antiparallel because ___

Answer 12

A - T has 2 H-bonds, while C - G has 3 H-bonds. Therefore, to keep each unit of nucleotide base same, the nucleotides must be oriented in the opposite, antiparallel direction.

Question 13

The difference between nucleotide and nucleoside is ___

Answer 13

Nucleotide has the phosphate group, while nucloeside has just the sugar and the nitrogenous base

Question 14

The experiment that showed that DNA replication was semiconservative is ___.

Answer 14

Meselson and Stahl experiment

Question 15

The four difference between Archaea & Bacteria, and Eukarya are ___

Answer 15

E has true nucleus, A&B do not;
E has multiple chromosomes organized by proteins, A&B have single chromosome;
E are multicellular, A&B are unicellular;
E has larger genomes than A&B

Question 16

Plasmids replicate in a ___ manner

Answer 16

relaxed/independent

Question 17

Central Dogma shows DNA –> RNA –> protein. The RNA is necessary for ___

Answer 17

movement across the nuclear envelope; DNA is within the nucleus, but protein is outside of it.

Question 18

The 3 differences between RNA and DNA are ___

Answer 18

DNA x2 helix, RNA x1 helix;
DNA has T, RNA has U;
DNA has 3’ OH, RNA has 2’ and 3’ OH

Question 19

Coding strand is ___; template strand is ___; the mRNA is an analogous copy of ___

Answer 19

the “original” DNA; the DNA mRNA gets transcribed from; coding strand