Ch. 14

Question 1

Why don’t chicken have teeth?

Answer 1

They have the genes require to produce the proteins to produce teeth, but they do not activate those genes
- In this case, a change in developmental cues, alters which genes are expressed in the ‘dental issue’

Question 2

What is the importance of gene regulation? (3)

Answer 2

1) Allows multicellular organisms to have differentiated cell types
2) Allows organisms to grow until they reach a particular size
3) Allows organisms to acclimate to changes in their environment

Question 3

How do cells adapt to their environment?
Lactose in the E.coli cell
4 steps

Answer 3

1) Lactose becomes available in the environment of the bacterium
2) Due to gene regulation, the bacterium produces more Lactose permease (proteins) and B-galactosidase
3) The bacterium readily uses the lactose until it is gone
4) Most proteins involved with lactose use are degraded

Question 4

What is able to break down lactose in the cell?

Answer 4

B-galactosidase

little green things

Question 5

What transports lactose into the cell?

Answer 5

Lactose permease

Transport protein

Question 6

Cells need to alter the amounts of ________ to survive in changing environments

Answer 6

Specific proteins

Question 7

In bacteria, at which level is the altering of the amount of specific proteins done at?

Answer 7

Transcription

Question 8

Increased Transcription = _______________= ____________

Answer 8

Increased Transcription = Increased Translation = Increased Protein

Question 9

Which phase does a gene change into mRNA?

Answer 9

Transcription

Question 10

Which phase does mRNA change into a protein?

Answer 10

Translation

Question 11

Which phase does the protein change into a functional protein? Eukaryotes!!

Answer 11

Post-translation

Question 12

_________ is critical in the development of multicellular

Answer 12

Gene regulation

Question 13

During human development what is needed at different stages?

Answer 13

During human development, different hemoglobins are required at different stages

Question 14

The correct _____ must be turned on and off at the correct times

Answer 14

genes

Question 15

Which type of cell has more layers of regulation? What are they?

Answer 15

Eukaryotes

1) Transcription
2) Processing of mRNAs
3) Translation
4) Post translation

Question 16

Eukaryote:

Transcriptional regulation

Answer 16

Determines which genes are transcribed

• Regulation of transcription
• Chromatin remodeling to make genes accessible for transcription

Question 17

Eukaryote:

Posttrancriptional regulation

Answer 17

Determines types and availability of mRNAs to ribosomes

• Variations in pre-mRNA processing
• Removal of masking proteins
• Variations in rate of mRNA breakdown
• RNA interference

Question 18

Eukaryote:

Translational regulation

Answer 18

Determines the rate at which proteins are made

- Variations in rate of initiation of protein synthesis

Question 19

Eukaryote:

Posttranslational regulation

Answer 19

Determines the availability of finished proteins

• Variations in rate of protein processing
• Removal of masking segments
• Variations in rate of protein breakdown

Question 20

What is a chicken-a-saurus?

Answer 20

A chicken with teeth, finger, and a tail

Question 21

T or F

It doesn’t matter where the proteins are made

Answer 21

False;

We need the right proteins made in the right amounts at the right time, in the right place

Question 22

What do changes in the sequence of DNA molecules do?

Answer 22

They may alter the production or function of a particular protein

Question 23

How can mutations be seen?

Answer 23

Mutations can be seen as generating a new allele for a given gene even if it does not cause a change in phenotype

Question 24

Small changes in the DNA sequence can cause ___ differences in __________

Answer 24

Big differences in protein sequence

Question 25

What can larger changes in the DNA sequence cause?

Answer 25

Larger changes in the DNA sequence cause the removal of entire genes or even the addition of new genes

Question 26

What are the 5 types of consequences of point mutations within the coding sequence of a structural gene?

Answer 26

Mutation in the DNA; Effect on polypeptide

1) None; None
2) Base substitution; SILENT- causes no change
3) Base substitution; MISSENSE - changes one amino acid
4) Base substitution; NONSENSE- changes to a stop codon
5) Addition (or deletion) of a single base; FRAMESHIFT- produces a different amino acid sequence

Question 27

Mutations can alter phenotypes by what? (4)

Answer 27

1) Generating a non-functional protein
2) Changing how a protein works
3) Altering when a gene is expressed
4) Changing where a gene is expressed

Question 28

One __________ in the hemoglobin gene causes sickle-cell anaemia

Answer 28

One base difference

Question 29

The T to A mutation in the sickle-cell disease example changes what?

Answer 29

Changes an amino acid in the protein from Glutamate to Valine
- From a hydrophilic to a hydrophobic amino acid

Question 30

Pleiotropic

Answer 30

When one base change causes a number of phenotypic changes

Question 31

In Whippet dogs, what can a mutation do?

Answer 31

A mutation in the Myostation Gene leads to increased muscle mass

Question 32

What does a 2 base deletion pair cause in the Myostatin gene?

Answer 32

Introduces and early stop codon

Question 33

Mutations

Answer 33

• In nature, mutations are random occurences

- They can range from simple base pair changes to loss of chromosome fragments

Question 34

Mutations can be caused by ___________________

Answer 34

any agents that damage DNA & random mistakes of the DNA replication process
- EX. UV light- too much sun = certain chemical viruses

Question 35

Which type of mutations will more likely be passed on?

Answer 35

Mutations that help an organism compete will be more likely to be passed on to the next generation than mutations that are not helpful

Question 36

_______ favours evolution

Mutations are/ are not always bad

Answer 36

Strong selective pressure favours evolution

Mutations are not always bad

Question 37

Malaria

Answer 37

A debilitating disease cause by trypanosome Plasmodium falciparum which is transferred to humans via bites from the mosquito Anopheles gambiae

Question 38

The blood cells of individuals with sickle-cell disease are less able to support the Plasmodium parasite, so what is the advantage?

Answer 38

So they do not get as sick from Malaria
So the disease allele provides a competitive advantage to individuals in certain environments
Especially in heterozygous form