The Molecular Basis Of Inheritance

Question 1

The Molecular Basis of Inheritance

Answer 1

DNA makes RNA makes Proteins

Question 2

Up until 1940, what did we know about our genetic material?

Answer 2

Until the 1940s, the case for proteins serving as the genetic material was stronger than the case for DNA

Proteins are made from 20 different amino acids and DNA was known to be made from just four kinds of nucleotides

Question 3

Molecular biology

Answer 3

The study of heredity at the molecular level, was usher in by the study of bacteria and viruses, revealed the role of DNA in heredity

Question 4

What did Fredric Griffith discover in 1928?

Answer 4

He discovered that a “transforming factor” could be transferred (by transformation) between bacterial cells

Question 5

What did Alfred Hershey and Martha Chase do in 1952?

Answer 5

They used bacteriophages to show that DNA is the genetic material of T2, a virus that infects the bacterium E. coli

Question 6

What was Hershey & Chases experiment?

Answer 6

Phases were labeled with radioactive sulfur to detect proteins or radioactive phosphorus to detect DNA
Bacteria were infected with either type of labeled phage to determine which substance was injected into cells and which remained outside the infected cell
DNA injected by the phage Carrie’s information that makes the bacteria make more viral phage particles

Question 7

What did the Hershey-Chase experiment demonstrate?

Answer 7

That genetic material was most likely DNA

Question 8

What does DNA stand for?

Answer 8

Deoxyribonucleic acid

Question 9

What is DNA made up of?

Answer 9

DNA is a polymer of nucleotides, each consisting of a nitrogenous base, a sugar, and a phosphate group

Question 10

What are the four nitrogenous bases?

Answer 10

Adenine (A), Thymine (T), Guanine (G), and Cytosine (C)

Question 11

What did Erwin Chargaff find out about DNA in 1950?

Answer 11

DNA compositions varies from one species to the next
The base composition of DNA varies between species
In any species the number of A and T bases is equal and the number of G and C bases is equal

Question 12

Who produced the X-ray image of aDNA molecule?

Answer 12

Rosalind Franklin, a graduate student with Maurice Watkins

Question 13

What did James Watson and Francis Crick deduce about DNA after seeing the X-ray?

Answer 13

They deduced that the shape of DNA was a helix

Question 14

How did they deduce that purine + pyrimidine was the correct combination for the nitrogenous bases?

Answer 14

Purine + Purine = to wide
Pyrimidine + Pyrimidine = too narrow
Purine + Pyrimidine = a width consistent with X-ray data

Question 15

What is the end of the phosphate group termed with?

Answer 15

A 5’ end

Question 16

What is the end of the hydroxyl group termed with?

Answer 16

A 3’ end

Question 17

Why was Rosalind Franklin not awarded the Nobel prize?

Answer 17

Because she died of cancer in 1958 of cancer and prizes are not awarded to posthumous candidates

Question 18

DNA replication

Answer 18

DNA polymerase catalyzes synthesis of new DNA by adding ducleotides to the 3’ end of a pre existing chain
Replication is continuous on the 3’ to 5’ template
Replication is discontinuous on the 5’ to 3’ template, forming short segments

Question 19

DNA polymerase

Answer 19

Adds nucleotides to a growing chain and proofreads and corrects improper base pairings

Question 20

DNA ligase

Answer 20

Joins smaller Okazaki fragments into a continuous chain

Question 21

How do cells package this DNA into chromosomes?

Answer 21

Stretched out the DNA in your cells would measure to about 4cm long
Chromosomal DNA is wound around proteins called histones to form chromatin
Groups of eight histones make nucleosides
Nucleosides coil into 30nm fibers which further loop in looped 300nm fibers which further fold into chromosomes

Question 22

Genomics

Answer 22

The scientific study of the whole genome; the study of an organism’s complete set of genes and their interactions

Question 23

What we’re the two main goal of the Hunan Genome Project (HGP)?

Answer 23

Determining the nucleotide sequence of all DNA in human genome
Identifying the location and sequence of every human gene

Question 24

Public approach

Answer 24

Page-by-page sequencing strategy: slow, labor-intensive (expensive) and yields high-quality output

Question 25

Private approach

Answer 25

Shotgun sequencing strategy: fast, cheap, computationally challenging and lower quality output

Question 26

Who is J. Craig Venter?

Answer 26

He led the private effort to sequence the human genome
Later admitted that the published sequence was for his own genome
Published the dog genome
Created the first synthetic genome to create a synthetic microbe with just 437 genes in 2016

Question 27

What do we know make sup humans genomes?

Answer 27

1.5% Exons, 24% introns and regulatory sequences, 15% unique non coding DNA, 15% repetitive DNA unrelated transposable elements and 44% repetitive DNA that includes transposable elements and related sequences

Question 28

What animal has the highest know gene count?

Answer 28

The Daphina pulex - a water flea with 31,000 genes