SB4

Question 1

Binomial system

Answer 1

A system for naming species which uses two Latin words.

Question 2

Evolution

Answer 2

The gradual change in the characteristics of a species over time

Question 3

Arid

Answer 3

Human like species. Around 1.2m and 50kg. Very long arms and long big toes on the sides of her feet.

Question 4

Lucy

Answer 4

1.07 m tall. Curved toes like modern day humans.

Question 5

Homo habillis

Answer 5

Quite short with long arms.

Question 6

Homo erectus

Answer 6

1.79m and strongly built

Question 7

Order of human like species

Answer 7

Ardi, Lucy, Homo habillis, Homo erectus, Homo sapiens.

Question 8

How do scientists find out how old fossils are?

Answer 8

By testing the age of the rock around the fossils.

Question 9

Genetic variation

Answer 9

The characteristics of individuals vary due to differences in genes

Question 10

Natural selection

Answer 10

The variations of some individuals make them better at coping with change than others, and therefore more likely to survive (survival of the fittest)

Question 11

Artificial selection

Answer 11

When humans choose certain organisms because they have useful characteristics, such as sheep with thick wool.

Question 12

Selective breeding

Answer 12

Breeding animals with similar characteristics so their offspring has those chosen characteristics, therefore increasing the abundance of species with specific characteristics (e.g thicker wool, a darker colour etc.)

Question 13

Why are plants and animals selectively bred?

Answer 13

• Disease resistance
• Yield
• Coping with certain environmental conditions
• Fast growth
• Flavour

Question 14

Genetic engineering

Answer 14

Genetic engineering involves changing the DNA of one organism often by inserting genes from another. This creates genetically modified organisms (GMOs)

Question 15

Genetic engineering of bacteria

Answer 15

• Restriction enzyme make staggered cuts in DNA molecules creating sections with unpaired bases at the end
• Restriction enzymes then cut plasmids open. By using the same enzyme, the plasmids have the same sticky ends
• Sections of DNA containing the insulin gene are mixed with the cut plasmids. The complimentary bases on the sticky ends pair up (with the use of ligase)
• The plasmids are then inserted back into bacteria, which are grown in huge tanks. The insulin they now make can easily be extracted