sample hsc

Question 1

cloning is a technique that would be used to increased numbers of endangered species. What effect would cloning have on genetic diversity of the species?

Answer 1

Whilst cloning would help increase the population size of the species it would decrease biodiversity.

Question 2

what is the process in gene cloning?

Answer 2

known genes are inserted into the DNA of host

Question 3

e.g. of gene cloning

Answer 3

bt gene into cotton to make the cotton disease resistant

Question 4

what is the process of whole organism cloning?

Answer 4

a single cell is used to make an entire organism through recombinant DNA technology to create genetically identical offspring to parent.

Question 5

e.g. of whole org cloning

Answer 5

often used in agriculture - fruit, crops, sheep…

Question 6

how have our knowledge of chromosome structure has led to reproductive technologies that have potential to alter the path of evolution?

Answer 6

reproductive technologies include artificial insemination, artificial pollination and whole org. cloning.
these technologies can reduce biodiversity - this reduction makes more species vulnerable to environmental changes and therefore at increased risk of extinction.
chromosomes consist of DNA combined with proteins they key understanding about

Question 7

idenitdy a transgenic species and state its use

Answer 7

golden rice is a transgenic organism that contains additional genes from daffodils and soil bacterium producing grains with increased amounts of beta-carotene, increasing the nutrient content of rice, therefore the transgenic organism is beneficial in solving vit A deficiencies in developing countries.

Question 8

discuss ethical issues that arise from the use of transgenic species

Answer 8

• who decided what is appropriate to introduce into another org?
• what is the purpose of the modification?
• costs involved
• effects on the environment

Question 9

“all mutations are harmful” discuss

Answer 9

“all mutations are harmful and incorrect” this statement is very broad and incorrect. Mutations are one of the contributing factors to genetic variation hence can be beneficial to society as it produces new alleles. Without these changes to DNA the process of natural selection wouldn’t exist and organisms would not be able to survive in a changing environment.

Question 10

outline the process of gene splicing to produce recombinant dna

Answer 10

gene splicing can be carried out by isolating the target DNA, then cutting using a restriction enzyme, this can then be recombined with the use of DNA ligase.

Question 11

state one difference between rna and dna

Answer 11

dna is has 2 strands whereas rna is single stranded

Question 12

give a use of pcr

Answer 12

pcr is used to amplify genes, making multiple copies which can then be used for analysis.

Question 13

state what happens in each step of pcr

Answer 13

1. denaturation - heated to 95 degrees - causing dna to denature - separating the strands
2. annealing - cooled to 55 degrees - allows primers to anneal
3. extension - heated to 72 degrees - polymerase moves down template synthesising new dna

Question 14

describe the roles of dna and rna in an application of biotech

Answer 14

new biotechnology applications in the treatment of diabetic patients have been developed, including the production of insulin through gene technology, a process that ultilises the human insulin gene and inserted into liver rather than damaged pancreatic tissue, as the liver cells are similar to the beta cells that produce insulin. the new gene or section of dna inserted into the patient liver cell nuceli. the translation of this section of dna into complementary bases then involves reverse transcription, which will create a copy of rna that can then produce the new polypeptide or protein. this in turn will complete the new strand and form the insulin.

Question 15

outline a type of t cells

Answer 15

cytotoxic t cells move to the site of infection and release chemicals that destroy infected cells.

Question 16

distinguish between the functions of b cells and t cells

Answer 16

the main difference between the functions of t and b lymphocytes is that b cels target pathogens in body fluids whereas t cells are responsible for hte elimination of pathogens located inside host cells. once b lymphocytes are exposed to a cytokine they proliferate and differentiate into memory cells and plasma cells where as t lymphocytes make direct contact with infected cells via special receptos that can identify and destroy them.