Chapter 9

Question 1

What is genetics and what does it study?

Answer 1

Genetics is the study of the inheritance, or heredity, of living things

1) the transmission of biological properties from parent to offspring
2) the expression and variation of traits
3) the structure and function of genetic material
4) the change of genetic material

Question 2

What is an organisms genome?

Answer 2

The sum total of the genetic material of an organism

Question 3

What are chromosomes?

Answer 3

Discrete cellular structures composed of neatly packaged DNA molecule

Question 4

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

Answer 4

Classical- the fundamental unit of hereditary responsible for a given trait in an organism (part of DNA that gives you a physical trait)

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

Question 5

Genes fall into what 3 basic categories?

Answer 5

1) structural genes
2) RNA genes
3) regulatory genes

Question 6

What is the difference between genotype and phenotype?

Answer 6

Genotype- genetic makeup of a gene or genome

Phenotype- physical expression of a gene

Question 7

What are the basic units of DNA?

Answer 7

Nucleotides

Question 8

How are nucleotides (what type of bond) to one another within each strand?

Answer 8

Covalent phosphate bonds

Question 9

How are the two opposite strands of DNA connected (what type of bond)?

Answer 9

Hydrogen bonds

Question 10

What are the 3 major types of RNA?

Answer 10

1) Messenger RNA (mRNA)
2) Transfer RNA (tRNA)
3) Ribosomal RNA (rRNA)

Question 11

What is transcription?

Answer 11

Conversion of DNA to RNA (specifically mRNA)

Question 12

What type of RNA is created during transcription?

Answer 12

mRNA

Question 13

What is translation?

Answer 13

The conversion of mRNA to protein

Question 14

What is the function of RNA polymerase?

Answer 14

To convert DNA to RNA

Question 15

What are triplets and codons?

Answer 15

Triplets- segments of 3 DNA nucleotides that encode for a single amino acid

Codons- when triplets are converted when DNA is converted to RNA during transcription

Question 16

What do triplets and codons code for?

Answer 16

Triplets code for single amino acids

When triplets codes of a DNA molecule are transcribed and translated it dictates the type and order of amino acids in the primary protein structure

Question 17

What is mutation?

Answer 17

Any permanent change in nucleotide sequence of an organism’s genome, a viral genome, extrachromosomal genetic elements

Question 18

What are the 2 types of chemical mutagens discussed?

Answer 18

Acridine dyes and nucleotide analogs

Question 19

What are the common sources of physical mutagens?

Answer 19

X-rays, gamma rays, and UV light rays

Question 20

What are the 3 types of point mutation?

Answer 20

1) additive- the insertion of an extra nucleotide
2) deletion- the removal of a nucleotide
3) substitution- a change from one nucleotide to another

Question 21

What is a missense mutation?

Answer 21

Any mutation in a nucleotide sequence that leads to placement of a different amino acid in the primary protein sequence

Question 22

What is a silent mutation?

Answer 22

Involves the alteration of a nucleotide base but doesn’t lead to a change in the amino acid sequence

Question 23

What is a nonsense mutation?

Answer 23

Changes a normal codon into a step codon and stole the production of the protein wherever it occurs in the sequence, often leading to incomplete and non-functional proteins

Question 24

Frameshift mutation

Answer 24

Occurs when a base pair is inserted or deleted/ shifts the “reading frame” and changes every amino acid that occurs after the shift

Question 25

What are the potential outcomes of a mutation? Are they always harmful?

Answer 25

They could result in cell death or inhibition, have no effect, or induce favorable changes

That are not always harmful

Question 26

What events lead to “industrial melanism,” and what effect did this have on the Peppered Moth populations in the immediate area?

Answer 26

Darkening pigments overtime due to pollution

Peppered Moths that were darker could blend in easier with melanized trees

Question 27

In general, what happens when bacteria experience a recombination event?

Answer 27

Bacteria donates DNA to another bacterium

Question 28

What is a recombinant organism?

Answer 28

Any organism that contains and expresses genes that originated in another organism

Question 29

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

Answer 29

Vertical= parent to offspring

Horizontal= one organism to another

Question 30

What is conjugation

Answer 30

Requires the attachment of 2 related species and the formation of a bridge that can transport DNA

Question 31

What is transformation?

Answer 31

Involves the transfer of “naked DNA” free floating DNA from dead cells

Question 32

What is transduction?

Answer 32

DNA transfer mediated through the action of a bacterial virus