Week 4/5

Question 1

Define karyotype?

Answer 1

An electromicrograph of cells that provides information about a developing foetus. This electromicrograph is cut up and arranged in homologous pairs (size order).

Question 2

Define down syndrome?

Answer 2

A common disorder affecting one in 600 births particularly the firstborn children of mothers over 40.
Children with Down syndrome have an extra chromosome in their cells (47 instead of 46)

Question 3

Define klinefelter’s syndrome?

Answer 3

A disorder affecting one in 500 males.
These people carry three sex chromosomes, (XXY instead of XY) and have severe acne and an awkward build.
They do not achieve sexual maturity without hormone treatment.
Even with treatment they remain sterile.

Question 4

Define turner’s syndrome?

Answer 4

A disorder affecting one in 2500 females. They only have one sex chromosome (XO) and have 45 chromosomes in each cell.
They fail to achieve sexual maturity without hormone treatment and are sterile because they don’t develop ovaries.

Question 5

Define ‘super’ males?

Answer 5

A condition affecting one in 3300 males.
They have XXY chromosomes and appear normal but are taller than average and tend to be less intelligent and more prone to aggressive behaviour.

Question 6

Define ‘super’ females?

Answer 6

A condition occurring in one in 800 females.

They have an XXX chromosome, are sexually undeveloped and are sterile.

Question 7

How does genetic modification work?

Answer 7

Genetic information is changed by inserting new genes.
These genes are copied to all the daughter cells when the parent cell divides by mitosis.
The cells mature into a completely new strain of plant.

Question 8

What can be added to plants when using genetic modification?

Answer 8

Insect resistance and increased nutrient value.

Question 9

What is canola?

Answer 9

A crop that produces edible oil.

Question 10

What did WA, VIC and NSW allow farmers to grow?

Answer 10

Genetically Modified canola resistant to herbicides commonly used to control weeds.

Question 11

What does GM canola allow?

Answer 11

It allows farmers to spray herbicide on the crop, killing the weeds but leaving the canola unaffected.

Question 12

What is white rice lacking?

Answer 12

Essential minerals and vitamins including vitamin A.

Question 13

What does vitamin A deficiency cause?

Answer 13

Childhood blindness that affects up to 500,000 children worldwide.

Question 14

Golden rice is genetically modified using what?

Answer 14

Genes from daffodils, corn and bacteria.

Question 15

What does golden rice contain?

Answer 15

Beta-carotene, the chemical that gives carrots their orange colour, and which the body converts into vitamin A.

Question 16

How much of the recommended dietary allowance of vitamin A would 225 grams of cooked golden rice provide?

Answer 16

50-60%

Question 17

Why was golden rice developed?

Answer 17

To help people in developing countries where blindness due to vitamin A deficiency is a problem.

Question 18

Why is GM rice not used for human consumption?

Answer 18

There has been a significant opposition from environmental and anti-globalisation groups to the commercial production of GM rice so its only grown for research.

Question 19

Define plasmids?

Answer 19

Separate rings of DNA.

Question 20

Define gene splicing?

Answer 20

When scientists cut plasmids open and splice (insert) desirable genes into the plasmid using enzymes.

Question 21

Define recombinant DNA technology?

Answer 21

The technology of combining DNA from different genes.

Question 22

What has recombinant DNA technology been used for?

Answer 22

Splicing the human gene that codes for insulin production into bacteria.

Question 23

What has recombinant DNA technology been to produce?

Answer 23

Large quantities of human insulin for use by people with diabetes.

Question 24

Define genome?

Answer 24

The genetic information carried by a haploid set of chromosomes.

Question 25

What is the Human Genome Project?

Answer 25

An international project that aimed to:
• identify all 20,000-25,000 genes in the human genome
• determine the sequence of the 3 billion base pairs that make up human chromosomes

Question 26

What percentage do humans share of their DNA?

Answer 26

99.9%

Question 27

Define single nucleotide polymorphism (SNPs)?

Answer 27

Locations that differ by only one base from one human to another.

Question 28

What common diseases may single nucleotide polymorphism (SNPs) be associated with?

Answer 28

Cardiovascular disease, diabetes, arthritis and cancer.

Question 29

What must be known about a gene to make gene testing for it useful?

Answer 29

The function of a gene.

Question 30

How many diseases have genetic tests available for them?

Answer 30

Over 400

Question 31

Why do people get genetic tests to see if they are carriers of diseases such as Cystic Fibrosis?

Answer 31

Knowledge of their genetic makeup can allow people to make decisions about weather or not to have children as they may pass on a disease.

Question 32

Which conditions do mothers get foetuses tested for?

Answer 32

Down syndrome, Turner’s syndrome and a Fragile X syndrome.

Question 33

Other uses for Gene/DNA testing?

Answer 33

Identification of a suspect in a crime investigation
Identification of the biological parents of a child
Analysis of the DNA of both the donor and the recipient (tissue typing) in cases of bone marrow or organ transplants

Question 34

Define gene therapy?

Answer 34

When the defective gene is replaced with a normal gene providing a potential to cure genetic diseases.

Question 35

Describe how researchers think genetics can be used to treat cancer?

Answer 35

They discovered a gene that can be switched off, reversing the growth of blood vessels in tumours and making the blood vessels more normal in size.

Question 36

Define genotype?

Answer 36

The actual genetic information carried by the individual.

Question 37

Define phenotype?

Answer 37

The observable characteristics of the individual.

Question 38

Define sex-linked genes?

Answer 38

Genes found on the X chromosome and not on the Y chromosome.