Final: Chapter 9- Genetics

Question 1

What is an organisms genome?

Answer 1

The sum total of the genetic material of an organism

Question 2

How is a gene described in both classical and molecular/biochemical terms?

Answer 2

Classical- the fundamental unit of heredity responsible for a given trait of an organism

Molecular/biochemical- site on the chromosome that provides information for a certain cell function

Question 3

What is the central dogma of biology and how has this dogma changed over the last decade with new information?

Answer 3

Central dogma= DNA> RNA>Protein

Change was that it is now thought that RNA does more work than originally thought

Question 4

What is the difference between genotype and phenotype?

Answer 4

Genotype= the sum of all genes that constitutes an organisms distinctive genetic makeup
Phenotype= the physical expression of a gene

Example: if an organism has brown hair, the phenotype is the brown hair, and the genotype is the specific gene, or genes that encode fo the brown color itself

Question 5

Genes fall into what three basic categories?

Answer 5

1) structural genes- encode for proteins
2) RNA genes- encode for RNA “machinery” used in protein synthesis
3) regulatory genes- control gene expression

Question 6

What are the complementary base pairing rules for DNA molecules?

Answer 6

Pyrines always pair with pyrimdimes

A=T
G=C

Question 7

What are transcription and translation?

Answer 7

Transcription= conversion of DNA to RNA

Translation= conversion of mRNA to proteins

Question 8

What is the difference between a spontaneous mutation and an induced mutation?

Answer 8

Spontaneous= a change on the DNA arising from errors in replication that occur randomly

Induced= result from exposure to physical or chemical agents, known as mutagens, that alter nucleotide sequences

Question 9

What are the potential outcomes of a mutation? Know the following types of mutations: silent, nonsense, and frameshift mutations.

Answer 9

Mutations can either have positive effects, negative effects, or no effect at all.

Missense= placement of different amino acids in the primary protein sequence 
Silent= involves the alteration of a nucleotide base but doesn’t lead to a change in the amino acid sequence
Nonsense= changes a normal codon into a stop codon/ it stops the production of the protein wherever it occurs in the sequence
Frameshift= occurs when a base pair is inserted or deleted/ shifts the “reading frame” and changes every amino acid that occurs after the shift

Question 10

What is the difference between horizontal gene transfer and vertical gene transfer?

Answer 10

Vertical is from parent to offspring

Horizontal is from one microbe to another through conjugation

Question 11

Know the following terms: conjugation, transformation, transduction.

Answer 11

Conjugation= requires the attachment of two related species and the formation of a bridge that can transport DNA
Transformation= involves the transfer of “naked DNA” often free floating DNA from dead cells
Transduction= DNA transfer mediated through the action of a bacterial virus