Selective Breeding

Question 1

What is selective Breeding?

Answer 1

The process by which humans breed plants and animals for particular genetic characteristics

Question 2

What are the steps to genetically breed?

Answer 2

1) Choose 2 patents with the desired characteristics from a mixed population
2) Breed these 2 together
3) From the offspring, choose those with the desired characteristics and breed them together
4) Repeat this process over many generations until all offspring show the desired charachteristics

Question 3

What is variation and what are the differences?

Answer 3

Differences in the characteristics of individuals in a population is called variation

These differences can be:

• The genes they have inherited (genetic causes)
• The conditions in which they have developed (environmental causes)
• A combination of genes and the environment

Question 4

What is the human genome?

Answer 4

The genome of an organisms is the entire genetic material of that organism ( contains 21,000 genes)

Question 5

What is DNA?

Answer 5

A chemical found in the nucleus of a cell. It is double stranded and a double helix molecule

Question 6

Why would scientists study the human genome?

Answer 6

• To search for genes linked to types of diseases

- To understand and be able to treat inherited disorders

Question 7

What is genetic screening?

Answer 7

Involves undergoing tests to discover person/embryonhas a gentic disorder or carrying a faulty allele

Question 8

How can embryos be genetically tested?

Answer 8

It can be done by:

• Amniocentesis
• analysing foetal cells found in the mothers blood

Question 9

What are the advantages for genetic testing?

Answer 9

• You can decide whether or not to have children or continue with the pregnancy
• Can plan ahead and get treatment for the condition (save money)
• They will know of there is a possibility of getting ill in the future

Question 10

What are the disadvantages of getting genetically screened?

Answer 10

• Risk of miscarriage or harm to the mother or foetus
• Tests may not be 100% accurate
• screening is expensive

Question 11

What is evolution ?

Answer 11

A change in the inherited characteristics of a population over time through a process of natural selection

Question 12

What is a species?

Answer 12

A species is a group of similar organisms capable of interbreeding to produce fertile offspring

Question 13

What are the advantages of selective breeding?

Answer 13

• It can produce animals and plants with desired characteristics
• It can increase production of milk/meat from cattle (increased profits for farmers
• Disease resistant crops produced
• Can produce domesticated animals with gentle nature so they can be kept as pets (eg. Labradoodle)

Question 14

What are the disadvantages of selective breeding?

Answer 14

• May force anumals to inbreed due to the small pool of genes
• Ethical issues as they do not breed naturally
• Reduces variation

Question 15

What is the definition of extinction?

Answer 15

Extinctions occur when there are no remaining individuals of species still alive

Question 16

Name 5 causes of extinction

Answer 16

• Habitat destruction
• Diseases that cannot be cured
• Climate change
• Fishing and hunting
• Food chain