DNA

Question 1

What is a mutation?

Answer 1

Permanent alterations in the nucleotide sequence of a genome of an organism.

Question 2

Main 2 types of mutations.

Answer 2

Gene mutations, Chromosome mutations/aberrations

Question 3

What are point mutations?

Answer 3

A type of gene mutation, which are small scale and involves only 1 altered nucleotide pair.

Question 4

What are the 3 types of gene mutations?

Answer 4

Single nucleotide pair substitutions, nucleotide pair insertions / deletions.

Question 5

What are restriction maps?

Answer 5

They are diagrams depicting the location of restriction sites relative to each other and the distances between these sites.

Question 6

How many STR markers are used?

Answer 6

13

Question 7

What are Small Tandem Repeats?

Answer 7

aka. microsatellite DNA. Present in eukaryotic DNA and are non coding sequences where 2 to 6 base pairs are repeated tandemly 100 to 1000 times so the lengths of these repeats vary.

Question 8

What are the raw materials required for PCR?

Answer 8

Deoxyribonucleotide triphosphates (dNTPs) - dATP, dGTP, dCTP, dTTP.
Single stranded DNA template
DNA primer
Mg2+

Question 9

What is the reason for using Taq DNA polymerase during PCR?

Answer 9

It is derived from the thermophilic bacterium Thermus aquaticus, so it does not denature at the high temperatures used for denaturation of the dsDNA.

Question 10

What is a DNA fingerprint/genetic profile?

Answer 10

Made up of the unique set of genetic markers of an individual.

Question 11

What are Vectors?

Answer 11

They are the vehicles that carry the DNA of interest into host cells for multiplication or cloning.

Question 12

What are recombinant vectors?

Answer 12

Vectors carrying the foreign DNA

Question 13

What are cloning vectors?

Answer 13

Vectors used in the cloning of DNA.

Question 14

Gene definition (rdna tech)

Answer 14

It is the fundamental physical and functional unit of heredity. it is a sequence of dna usually residing on a particular locus of a particular chromosome that contributes to the development of 1 or more traits by coding for specific proteins or peptides.

Question 15

What is DNA sequencing?

Answer 15

Process of determining the precise order of bases of nucleotides in the dna molecule.

Question 16

Explain transformation as a dna delivery system

Answer 16

based on the ability to take up dna from surroundings through the plasma membrane
inefficient. treatments present to increase competency of the host cells
large amounts of DNA and host cells are mixed.
(definition of transformation)

Question 17

Explain transduction as a dna delivery system

Answer 17

based on the ability of a bacteriophage to infect the host cell. can use various viruses infecting plants and animals to transfer dna to plant and animal cells.
dna is delivered through the normal mode of infection.
dna of interest is incorporated into the viral genome, packaged into the capsid which provides protection. more efficient than transfomration.

Question 18

explain the procedure when using a gene gun

Answer 18

small particles of heavy metals like gold are coated with large amounts of dna of interest and are shot at high velocities into the host cells.

Question 19

What is unique about the mode of infection of Agrobacterium? What is this disease called?

Answer 19

It stimulates plant cells to form a tumor and the bacterium lives inside this. it is called crown gall disease

Question 20

How does a tumor form during the infection of Agrobacterium?

Answer 20

the plant cells are genetically modified by a segment of dna (T-DNA) of a plasmid (Ti plasmid) of the bacterium.

Question 21

What genes are present in T-DNA?

Answer 21

genes related to pathogenicity and for tumor formation

Question 22

Why are the left and right border sequences of T-DNA important?

Answer 22

these are required for the transfer of dna into plant cells.

Question 23

What is needed for the DNA of interest to be copied?

Answer 23

Must be inserted into DNA having an ori site that can replicate independently of chromosomal DNA.

Question 24

What is a cloning site?

Answer 24

Site in the vector where the DNA to be cloned is inserted.

Question 25

What is a multiple cloning site?

Answer 25

Cloning site that contains dna sequence carrying sites for many restriction enzymes. so many restriction enzymes can be used to cut dna.

Question 26

what is an advantage of PCR?

Answer 26

obtaining large amounts of copies of dna with high accuracy.

Question 27

What is the application of PCR in evolutionary biology?

Answer 27

Used to identify and explore relationships among different species.

Question 28

introduction to changes in structure of chromosomes. what are the possible changes that can occur?

Answer 28

changes in structure involve chunks of chromosomes, containing several to hundreds of genes. these can be lost, copied and moved to another chromosome ( copy and paste ) , moved to another chromosome (cut and paste) or their orientation can be changed

Question 29

What happens if the cutting of a chromosome occurs through a gene?

Answer 29

The gene loses its function.

Question 30

Why are polyploids considered to be more “normal” than aneuploids?

Answer 30

In polyploids, the genetic balance is maintained while in aneuploids, the genetic balance is lost.

Question 31

what is gene expression? what are its end products?

Answer 31

the process of utilising the information stored in a gene to produce a functional gene product, which is usually a polypeptide that becomes a protein after modifications, or tRNA or rRNA.