Chapter 2

Question 1

What are the 3 kinds of ribosomes and where are their proteins created?

Answer 1

• ribosomes on membrane of ER
  -> intermembrane proteins
• inter-membrane ribosomes on ER
  -> proteins inside ER
• ribosomes free floating outside of ER
  -> cytoplasmic proteins

Question 2

What is the coding strand (+ strand)?

Answer 2

The strand that codes for the mRNA that creates the protein (ex: if ATGC is sequence on +coding DNA strand, then it’s complementary strand (TACG) is transcribed into AUGC on mRNA strand)

*AUG is START CODON

Question 3

What is a Bacteriophage?

Answer 3

A virus that attacks bacteria

Question 4

What is Transduction?

Answer 4

DNA injected or pulled in to bacteria spontaneously (usually by virus)

Question 5

What is Transformation?

Answer 5

Bacteria purposefully pulling free-floating DNA into itself

Question 6

What is Conjugation?

Answer 6

When 2 bacteria cells connect to transfer DNA
(basically bacterial sexual reproduction!)

Question 7

What is a Transposon?

Answer 7

A nucleic acid sequence in DNA that can change its position within a genome, sometimes creating or reversing mutations and altering the cell’s genetic identity and genome size

Question 8

What is a plasmid?

Answer 8

A small, often circular DNA molecule found in bacteria and other cells

Question 9

How is a trait different than a gene? Can multiple genes be involved in the expression of one trait?

Answer 9

A trait is the expression of the gene. Multiple genes CAN be involved in the expression of one trait.

Question 10

What is a gene?

Answer 10

A section of DNA that codes for (usually) 1 protein.

Question 11

What did Jean-Baptiste Lamarck do?

Answer 11

Before Darwin’s “Natural Selection”, Lamark proposed that traits are inherited based on lifetyle choices of parents.

Question 12

What did Charles Darwin do?

Answer 12

Proposed Evolution: survival of the fittest (beneficial mutations are passed on)

Question 13

What did Gregor Mendel do?

Answer 13

Discovered and described the transmission of genetic traits

Question 14

What did Walter Flemming do?

Answer 14

Discovered MITOSIS (condensed chromosomes!)

First to detail the chromosomal movements in the process of mitosis

Question 15

What did Thomas Hunt Morgan do?

Answer 15

Proposed that chromosomes are made of genes!

• Brought to light Mendel’s writings:
  Discovered that genes are stored in chromosomes inside the nuclei

Question 16

What did Oswald Avery do (with MacLeod and McCarty)?

Answer 16

RAT EXPERIMENT
Discovered that genes are made of DNA!
(not protein–as previously believed)

Question 17

What did Rosalind Franklin do?

Answer 17

Revealed double helix of DNA with her “photo 51”

Question 18

What did Watson & Crick do?

Answer 18

They were the first scientists to formulate an accurate description of DNA’s complex, double-helical structure

Question 19

What are Gregor Mendel’s 2 Laws?

Answer 19

1) The Law of Segregation
2) The Law of Independent Assortment

Question 20

Do you know these terms?
P generation,
F1 generation,
F2 generation,
Purebred,
Hybrid,
Gene,
Allele,
Phenotype,
Genotype,
Homozygous,
Heterozygous,
Dominant allele,
Recessive allele

Answer 20

YES :)

Parents,
1st generation,
2nd generation,
Identical alleles,
Different alleles,
DNA section,
Variation of a gene,
Observable expression,
Sequence of DNA,
Two matching genes,
Genes don’t match,
Overrules other allele,
Very passive (need 2)

Question 21

What is The Law of Segregation?

When does this occur?

Answer 21

ALLELES SEPARATE:

1 chromosome from mom and 1 chromosome from dad (both code for the same genes) contain specific “alleles”.
* 2 alleles for the same gene in every cell
* OCCURS IN ANAPHASE 1

Question 22

What does Purebred mean?

Answer 22

Having identical alleles for whatever gene you’re interested in
(homozygous)

Question 23

What is the difference between genotype and phenotype?

Answer 23

Genotype: (DNA) genes

Phenotype: (physical) traits

• two different genotypes can potentially both result in the same phenotype

Question 24

What is The Law of Independent Assortment?

Where does this occur?

Answer 24

The alleles of two (or more) different genes get sorted into gametes independently of one another

• Only for looking at more than one gene
• Occurs during Prophase 1! (crossing-over)

Question 25

What are the 3 main components of Non-Mendelian Genetics?

Answer 25

INCOMPLETE DOMINANCE:
partial expression of each allele
(ex: Rr flower looks pink instead of red or white)

CODOMINANCE:
full expression of each allele
(ex: blood type can be A, B, or AB)

LINKED GENES:
two genes stay together while passed onto offspring, so the law of independent assortment is broken
(ex: eye color and skin color are often linked)

Question 26

What is Allelic Exclusion and how does it relate to gene expression?

Answer 26

Only one allele of a gene is expressed while the other allele is silenced.

(This phenomenon is most notable for playing a role in the development of B lymphocytes, where allelic exclusion allows for each mature B lymphocyte to express only one type of immunoglobulin.)

Question 27

Define and diagram the cell cycle including the following stages: G0, G1, S, G2 and M. In what stages is DNA condensed as chromosomes and in what stages is it not (chromatin)?

Answer 27

INTERPHASE:
G0 - rest
G1 - cell growth
S - dna replication
G2 - mitosis prep

MITOSIS
M - cell division

• Cromatin (loose DNA+proteins) appears during G1 and lasts through S until G2
• DNA condenses in prophase of Mitosis (beginnnig of M phase)