Deck 10: Biotechnology

Question 1

Figure 10.7 Why was Dolly a Finn-Dorset and not a Scottish Blackface sheep?

Answer 1

Dolly was a product of reproductive cloning that is, a technique by which a clone or identical copy of an entire multi-cellular organism is produced.
As multi-cellular organisms multiply by means of sexual reproduction, a clone of either of the parent is impossible. Sperm and egg giving rise to a zygote are haploid and one set of chromosome from each of the parent unites to gives rise to a diploid zygote. Meanwhile, components of egg cytoplasm are also essential for the development of a healthy embryo.
The process of developing an artificially cloned individual involves the removal of the haploid nucleus from the egg and inserting a diploid nucleus from other individual, that is, the donor. This egg is then stimulated to divide until blastula stage, when it is implanted into surrogate mother. The embryo then, undergoes its normal development and a healthy offspring is the result.
In case of Dolly, a Finn-Dorset , the egg cell was from the Scottish Blackface sheep (Cytoplasmic donor) while the nucleus inserted in the egg was from a Finn-Dorset (Nuclear donor). As the genetic information important for the phenotypic and genotypic characteristic of the organisms is encoded in the DNA (deoxyribonucleic acid) present in the nucleus, Dolly developed the characters of the nuclear donor that is, of a Finn-Dorset.
Hence, although the egg (original cell) came from a Scottish Blackface sheep, Dolly had phenotype as well as genotype of a Finn-Dorset because DNA was from a Finn-Dorset. This is the reason for Dolly being a Finn-Dorset sheep and not a Scottish Blackface sheep.

Question 2

In gel electrophoresis of DNA, the different bands in the final gel form because the DNA molecules ________.

A) are from different organisms
B) have different lengths
C) have different nucleotide compositions
D) have different genes

Answer 2

Gel electrophoresis is the technique which is used to separate DNA (Deoxyribonucleic Acid) molecules on the basis of their charge and size. The nucleic acids are loaded onto one end of the gel matrix and application of an electric current is done which causes the negatively charged molecules to get pulled towards the opposite end of the gel matrix.
The different bands in the gel are therefore not formed due to DNA being from different organisms as DNA is taken from the same organism for gel electrophoresis. Having different genes and composition of nucleotides is also not the basis for separation of bands in gel electrophoresis.
Hence, the options a., c. and d. are incorrect.
In gel electrophoresis, smaller molecules move faster through the pores of the gel than larger molecules. Fragments get separated based on their size due to this difference in the migration rate.
Hence, the correct answer is option

Question 3

In the reproductive cloning of an animal, the genome of the cloned individual comes from ________.

A) a sperm cell
B) an egg cell
C) any gamete cell
D) a body cell

Answer 3

Reproductive cloning is the method of re-creating or making a clone of a whole multicellular organism. In the method, egg cell of an individual is taken and its haploid nucleus removed. Then from the second individual, that is, the donor, the diploid nucleus is taken from the body cell and put into the egg cell. Then the egg is stimulated in order to make it divide so that development continues.
As the genome is obtained from the donor individual, therefore it is not obtained from the egg cell, any gamete cell or an egg cell.
Hence, the options a., b. and c. are incorrect.
The genome of the individual which has been cloned comes from the diploid nucleus which has been taken from the body cell.
Hence, the correct answer is option

Question 4

What carries a gene from one organism into a bacteria cell?

A) a plasmid
B) an electrophoresis gel
C) a restriction enzyme
D) polymerase chain reaction

Question 5

What is a genetically modified organism (GMO)?

A) a plant with certain genes removed
B) an organism with an artificially altered genome
C) a hybrid organism
D) any agricultural organism produced by breeding or biotechnology

Question 6

What is the role of Agrobacterium tumefaciens in the production of transgenic plants?

A) Genes from A. tumefaciens are inserted into plant DNA to give the plant different traits.
B) Transgenic plants have been given resistance to the pest A. tumefaciens.
C) A. tumefaciens is used as a vector to move genes into plant cells.
D) Plant genes are incorporated into the genome of Agrobacterium tumefaciens.

Question 7

What is the most challenging issue facing genome sequencing?

A) the inability to develop fast and accurate sequencing techniques
B) the ethics of using information from genomes at the individual level
C) the availability and stability of DNA
D) all of the above

Question 8

Genomics can be used in agriculture to:

A) generate new hybrid strains
B) improve disease resistance
C) improve yield
D) all of the above

Question 9

What kind of diseases are studied using genome-wide association studies?

A) viral diseases
B) single-gene inherited diseases
C) diseases caused by multiple genes
D) diseases caused by environmental factors

Question 10

What is the purpose and benefit of the polymerase chain reaction?

Question 11

Today, it is possible for a diabetic patient to purchase human insulin from a pharmacist. What technology makes this possible and why is it a benefit over how things used to be?

Question 12

Describe two of the applications for genome mapping.

Question 13

Identify a possible advantage and a possible disadvantage of a genetic test that would identify genes in individuals that increase their probability of having Alzheimer's disease later in life.