DNA and Genetics

1
Assessment of LO 3 Ethical dilemmas

• Discuss whether insurance companies should have
  the right to refuse cover for a child if prenatal
  tests results indicate that the child will suffer
  a severe genetic disorder?
• Using the technology available today, suppose
  that you could learn with certainty, that by the
  age of 60 you would suffer from a genetic
  disease. Would you like to know?
• Makae and Sipho want to marry. Show, in a
  family tree form, all the possible genotypes of a
  child they intend to have. (Gg xGg) gg cystic
  fibrosis.

2
Genetic counseling

• Genetic counseling, a process where information
  and advice is given about inherited disorders.
  Often it is given to a couple who are planning to
  have a child but who suspect that there is a
  greater than normal risk of the child being
  affected by a genetic disorder

3
Genetic modification
4

• In genetic modification, scientists use
  restriction enzymes to isolate a segment of DNA
  that contains a particular gene of interest (1).
• In this instance, it is a human gene. A plasmid
  extracted from its bacteria and treated with the
  same restriction enzyme can hybridize with this
  fragments sticky ends of complementary DNA
  (2).
• The hybrid plasmid is reincorporated into the
  bacterial cell, where it replicates as part of
  the cells DNA (3).
• A large number of daughter cells can be cultured
  and studied, and their gene products may be
  extracted for further use (4).

5
Examples of Genetic modification
A scorpion venom gene, engineered into a virus,
is used as a spray to kill insects
Poultry with modified genes are resistant to
salmonella food poisoning bacteria, and lay
bigger eggs more often
6
Salmon eggs have genes inserted into them which
make them grow ten times faster than normal
Genetically modified pigs grow faster, have less
fat, and produced cholesterol-free meat
7
Assessment (LO3)
These tomatoes have been given genes from fish
which make them frost resistant and fresh for
longer. Would you eat them?
8
Do a survey on the following two questions Do
people know what is genetic modified food? Will
they eat genetic modified food?

• Design a questionnaire
• Use two groups of people
• Group 1 15 - 30
• Group 2 30 50 years old
• Draw bar graph on the results obtained in the two
  questions plot both sets of data on the same
  graph
• Draw a Pie chart with the results
• Write down a hypothesis for your investigation
• Write down your independent and dependant factors
• Write down your conclusion for this investigation

LO1 assessment
9
Extinct zebra
Etienne
Tracy
Interbreeding
10
The story of the extinct zebra

• Baby of the thought extinct zebra is in the Cape
  museum since 1858 stuffed by taxidermist
• Later Mr Rau curator of the museum decided to
  send it to be re-stuffed
• They discovered some muscle tissue left on the
  inside of the skin
• DNA testing show this zebra is related to Equus
  burchelli (still alive today)
• Special inbreeding programme was started and
  today we have back the original species

11
Resources

• The internet
• www.google images
• http//rubistar.4teachers.org
• Britannica 2006
• Encarta 2006