Section 4 - Natural selection and genetic modification - Natural selection, evolution and classification

Question 1

3 things that act as selection pressures?

Answer 1

Predation, competition for resources and diseases

Question 2

What provides evidence for evolution and how?

Answer 2

Bacteria - bacterium develops mutation in allele which makes it resistant to particular antibiotic. Others die but mutated one survives and reproduces. Allele passed on to offspring
Fossils - by arranging fossils in chronological order to observe gradual changes in organisms

Question 3

What are humans and their ancestors known as?

Answer 3

Hominids

Question 4

Ardi species, age and location found?

Answer 4

Ardipithecus ramidus, 4.4 million years old, found in Ethiopia

Question 5

Structure of Ardi? 3

Answer 5

• Structure of feet suggest climbed trees - ape-like big toe to grasp branches
• Long arms and short legs (more ape-like than human) and brain size same as chimpanzee
• Structure of legs suggest walked upright like human and structure of hand bones suggest she didn’t use hands to help he walk like apes

Question 6

Lucy species, age and location found?

Answer 6

Australopithecus afarensis, 3.2 million years old, found in Ethiopia

Question 7

Structure of Lucy? 4

Answer 7

• Arched feet, more adapted to walking than climbing but no ape-like big toe
• Size of arms and legs between what expected apes and humans
• Slightly larger brain than Ardi’s but similar size to chimp’s
• Structure of leg bones and feet suggest walked upright but more efficiently than Ardi

Question 8

Turkana Boy species, age and location found?

Answer 8

Homo erectus, 1.6 million years old, found in Kenya

Question 9

Structure of Turkana Boy? 2

Answer 9

• Short arms and long legs much more like human than ape, and brain size much larger than Lucy’s, similar to human brain size
• Structure of lens and feet suggest he even better adapted to walking upright than Lucy

Question 10

Tool type and use by homo Habilis (2.5 - 1.5 million years ago)?

Answer 10

Simple stone tools called pebble tools by hitting rocks together to make sharp flakes. Used to scrape meat from bones or crack bones open

Question 11

Tool type and use by Homo Erectus (2 - 0.3 million years ago)?

Answer 11

Sculpted rocks into shapes to produce more complex tools like simple hand-axes. Used to hunt, dig, chop and scrape meat from bones

Question 12

Tool type and use by Homo Neanderthalis (300,000 - 25,000 years ago)?

Answer 12

More complex tools. Evidence of flint tools, pointed tools and wooden spears

Question 13

Tool type and use by Homo sapiens (200,000 - now)?

Answer 13

Flint tools widely used. Pointed tools including arrowheads, fish hooks, buttons and needles appeared around 50,000 years ago

Question 14

3 ways to work out how old an ancient stone tool or hominid fossil is?

Answer 14

Structural features, using stratigraphy (study of rock layers) or carbon-14 dating

Question 15

5 group names in Kingdom classification system?

Answer 15

Animals, plants, fungi, prokaryotes, protists

Question 16

Names of domains in Three Domain System and what they include?

Answer 16

Archaea - look similar to bacteria but quite different, first found in extreme places
Bacteria - contains true bacteria like E. coli
Eukarya - Includes broad range of organisms including fungi, plants, animals and protists