Inheritance, Variation & Evolution

Question 1

What are the 7 stages of Darwin’s Theory of Evolution?

Answer 1

1. Genetic Variation (which occurs through random mutation)
2. Environmental Change (which creates competition)
3. Natural Selection
4. Reproduction and Inheritance
5. Evolution (which occurs over time)
6. Speciation (the evolution of a new species)
7. Geographical Isolation (over time some of these species end up in different parts of the world.)

Question 2

What is genetic engineering?

Answer 2

The modification of an organism’s genome by introducing another gene from a different organism, to produce a desired characteristic.

Question 3

Give 3 examples of genetic engineering. (One in bacteria, one in plants, and one in animals.)

Answer 3

Bacteria - Producing Insulin
Plants - Golden/Vitamin A rice
Animals - Goats that produce lysozyme (found in human breast milk, can act as an antimicrobial)

Question 4

Outline the process of genetic engineering.

Answer 4

1) Restriction enzymes cut a desired gene from a chromosome. Sticky ends are left on either side of the useful gene.
2) The vector (usually plasmid DNA) is cut by the restriction enzymes. The exposed sections now have sticky ends.
3) An enzyme called ligase causes the target gene anneal to the vector to become a two-gene segment. Not every vector contains the two gene segment
4) A marker gene is bonded to the complimentary sticky ends and identifies if the useful genes have been successfully inserted.
5) The vector with the inserted gene is inserted into the required cells
6) If the embryo/egg has not yet differentiated, and the vector is introduced, it will differentiate to produce an organism that carries the desired characteristic.

Question 5

What is selective breeding

Answer 5

When humans choose specific organisms to breed based off of their genetic characteristics.

Question 6

List two negatives of selective breeding

Answer 6

• Inbreeding, which means they can be more susceptible to disease or inherited defects. (e.g. French bulldogs which have flat faces that lead to respiratory issues)
• Reduced variation, which means they may find it harder to adapt to environmental change

Question 7

List two positives of selective breeding

Answer 7

• Can increase yield in crops through disease resistant genes
• Can produce desirable traits in different organisms (e.g breeds of dogs)
• Can help an endangered species grow the population to decrease the chances they go extinct

(any of the above)

Question 8

Why was Darwin met with resistance when he first proposed his ideas?

Answer 8

1. Many scientists had regarded his theory as inconclusive
2. Genes had not been discovered at the time, he was not able to suggest how the characteristics had been passed down
3. Darwin’s ideas contradicted contemporary religious views

Question 9

Who else worked with Charles Darwin on the theory of evolution?

Answer 9

Alfred Russel Wallace

Question 10

Name 3 ways in which animals and plants may be adapted to their environment.

Answer 10

• through their behaviour
• through their structure
• through their function

Question 11

What is evolution?

Answer 11

The gradual change of inherited characteristics in biological populations over time. Usually driven by natural selection.

Question 12

Why is antibiotic-resistant bacteria evidence of evolution?

Answer 12

There is genetic variation in the species of bacteria. Some have greater resistance to some antibiotics than others. When exposed to antibiotics that target this strain of bacteria, where the dosage is incomplete, the ones with the more resistant genes survive, whereas the less resistant ones die off. The more resistant bacteria cells reproduce over many generations (bacteria can reproduce at a rapid rate) and all offspring carry the more resistant trait. This example of evolution is the same process that Darwin describes of all species on earth, just with different environmental changes and inherited characteristics.

Question 13

What is the pentadactyl limb and how is it an example of evolution?

Answer 13

The pentadactyl limb is a common trait in many vertebrates (animals with a backbone). They have a 5 finger bone structure (e.g, humans, bats, cats, whales) This characteristic suggest many vertebrates descended from a common ancestor.

Question 14

What are the 3 causes of fossilisation?

Answer 14

1) In some conditions, decomposers cannot act and therefore preservation is possible. (e.g, in glaciers where there is extreme cold and peat bogs where there is extreme acidity)
2) When soft materials harden, they can produce casts of an organism that has already decayed.
3) The harder parts of decaying organisms are replaced my minerals, which create distinct rock like indentations on the sediment around it which has already turned to rock.

Question 15

How many years back is Lucy dated?

Answer 15

3.2 Million

Question 16

How many years back is Ardi dated?

Answer 16

4.4 Million

Question 17

How many million years ago have the oldest stone tools been dated back to?

Answer 17

2.6 Million years

Question 18

Remember: (Do) Keep Pond…

Recite the correct decending order of the Linnaean classification system:

Answer 18

Kingdom
Phylum
Class
Order
Family
Genus
Species

Domain would be at the top.

Question 19

Felis catus - What is the Species name, and what is the Genus name?

Answer 19

Catus - Species name
Felis - Genus name

Question 20

The Scientific name for a horses is Equus caballus - What is the Species name, and what is the Genus name?

Answer 20

Equus - Genus name
Caballus - Species name

The genus name is ALWAYS at the beginning. E.g, HOMO Sapien.

Question 21

Classification by Carl Linneus was based on characteristics and structures. State the developments that have occurred to change this.

Answer 21

The development of the microscope meant smaller structures within cells could be found. These structures could then help to distinguish one organism to another.

Question 22

Who proposed the 3 Domain System and what are the distinguishing qualities between the 3 Domains?

Answer 22

Carl Richard Woese:

Archea (primitive bacteria, often habiting extreme conditions)
Bacteria (true bacteria)
Eukarya (organisms with complex sub-cellular structures, e.g, protists and fungi)

Question 23

What is food security?

Answer 23

When the entire population of earth has enough access to nutritious food to stay healthy.

Question 24

Give an example of biological control:

Answer 24

e.g, the reduction of opuntia in australian farm land. They spread through the farm land, and made it unsuitable for farming. The reduction of this species means more crops can be grown with better yield and efficiency.

e.g.2, flies are used to kill red imported fire ants, which damage crops on farmlands and reduces yield.

(any example is okay)

Question 25

What is battery farming and why is it used?

Answer 25

Keeping farm animals indoors in crowded conditions to increase efficiency.
- this ensures they are kept warm and refrain from a lot of movement. this reduces the amount of energy that is transferred to the environment.

Question 26

What is biological control?

Answer 26

The reduction in species of pests due to a predator being introduced into it’s habitat.

Question 27

How is the pentadactyl limb of a horse an example of evolution?

Answer 27

An environmental change occured - watterlogged grounds became dryer and therefore horeses with smaller feet had a genetic advantage. They were able to run away from predators faster and therefore more were able to reproduce and have offspring who carried this trait over many generations.