Natural Selection And Genetic Modification

Question 1

Why did people start thinking humans were animals?

Answer 1

Carl Linnaeus published his system of classification and suggested that humans were related to monkeys

Question 2

What was Carl Linnaeus’ system of classification?

Answer 2

Binomial system

Question 3

What is evolution?

Answer 3

A gradual change in the characteristics of a species over time

Question 4

Why do fossils not show smooth changes over time?

Answer 4

Some have not been discovered

Question 5

Features of the Ardipithecus ramidus (Ardi)

Answer 5

• 1.2m tall
• legs shoe it may have been able to walk upright
• long arms & long big toe that would have allowed it to climb trees

Question 6

Features of the Australopithecus afaerensis (Lucy)

Answer 6

• 1.07m tall
• could probably walk upright
• toe bones arranged in same way as modern humans but they were more curved

Question 7

Features of homo habilis

Answer 7

• short
• long arms
• walked upright

Question 8

Features of homo erectus

Answer 8

• tall (1.79m)

- strongly built

Question 9

What is the earliest scientists can see human-like animals using stone tools?

Answer 9

3.3 million years ago

Question 10

How do scientists know how old the tool is?

Answer 10

They can work out the ages of the layers of rock and assume the tool is the same age as that layer of rock

Question 11

What would the oldest stone tools be used for?

Answer 11

Simple, but would have helped with skinning an animal or cutting up meat

Question 12

Who came up with evolution?

Answer 12

Charles Darwin and Alfred Russel Wallace

Question 13

What is genetic variation?

Answer 13

The characteristics of individuals vary (due to differences in genes)

Question 14

What is environmental change?

Answer 14

Conditions change in an area change

Question 15

What is natural selection?

Answer 15

By chance, the variations of some individuals make them better at coping with the change than others, and more likely to survive

Question 16

What is inheritance?

Answer 16

The survivors breed and pass on their variations to their offspring. So the next generation contains more individuals with the ‘better adapted variations’

Question 17

What are the stages of evolution?

Answer 17

• genetic variation
• environmental change
• natural selection
• inheritance
• evolution

Question 18

What is a pentadactal limb?

Answer 18

A limb that has 5 digits (fingers and thumbs)

Question 19

Give examples of some animals that have the pentadactal limb

Answer 19

• human
• bat
• chicken
• turtle
• dolphin

Question 20

What do the pentadactal limb similarities suggest?

Answer 20

Evolution from a common ancestor

Question 21

What are the 5 kingdoms?

Answer 21

• animals
• plants
• fungi
• protists
• prokaryotes

Question 22

What are the 3 domains?

Answer 22

• archaea
• bacteria
• eukarya

Question 23

What are the main characteristics of animals?

Answer 23

• multicellular (with cells arranged as tissues and organs)
• no cell walls
• cells have nuclei

Question 24

What are the main characteristics of plants?

Answer 24

• multicellular (with cells arranged as tissues and organs)
• chloroplasts
• cells have nuclei
• cellulose cell walls

Question 25

What are the main characteristics of fungi?

Answer 25

- multicellular (apart from yeast) - live on or on the dead matter they feed off - cells have nuclei - cells walls contain chitin (not cellulose)

Question 26

What are features of protists?

Answer 26

- mostly unicellular - cells have nuclei - some have cell walls (made of different substances not chitin)

Question 27

Features of prokaryotes

Answer 27

- unicellular - cells do not have nuclei - flexible cell walls

Question 28

What are the features of archea?

Answer 28

- cells with no nucleus | - genes contain unused sections of DNA

Question 29

What are the features of bacteria?

Answer 29

- cells with no nucleus | - no unused sections in genes

Question 30

Features of eukarya

Answer 30

- cells with a nucleus | - unused sections in genes

Question 31

What is artificial selection?

Answer 31

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

Question 32

What is selective breeding?

Answer 32

When humans choose an organism that has a certain characteristic and breed to have more of these organisms, making that chosen characteristic more and more obvious

Question 33

What are plants and animals often selectively bred for?

Answer 33

- disease resistance - yield (how much useful product they make) - coping with certain environmental conditions - fast growth - flavour

Question 34

What is genetic engineering?

Answer 34

Altering the genome of an organism, usually by adding genes from another species (also known as genetic modification)

Question 35

What is tissue culture?

Answer 35

The growing of cells or tissues in a liquid containing nutrients or on a solid medium

Question 36

What is a callus?

Answer 36

A clump of undifferentiated cells

Question 37

What is tissue culture used for?

Answer 37

- To produce new plants if very rare species which are at a risk of extinction - to produce more individuals of plant species that may be difficult to grow from seed - produce clones of GM plants

Question 38

What are uses of tissue cultures in medicine?

Answer 38

- to study viruses - to study how cells communicate with each other - cultures of cancers used to study cancer

Question 39

What are the risks of selective breeding?

Answer 39

- only certain alleles are selected, others become rare or disappear - all organisms are very similar so if there is a change in conditions (e.g a new disease)affects one organism all the others are affected

Question 40

What are the issues with genetic engineering?

Answer 40

- seeds are expensive - there’s genes may have unknown consequences in wild plants - not all people can use the insulin from GM bacteria

Question 41

What are insecticides?

Answer 41

A substance used to kill pests

Question 42

What is an advantage of GM bt toxin?

Answer 42

- It only affects insects that chew the plants tissues | - insect predators unharmed

Question 43

Problems with crop plants that make their own insecticide?

Answer 43

-insects can develop resistance to toxin

Question 44

What is a biological control?

Answer 44

Using organisms to control pests