Genetic engeneering - topic 4 (pg 29-35) paper 1

Question 1

what did Charles Darwin do

Answer 1

developed an evolution theory by means of natural selection

Question 2

Natural selection

Answer 2

• some individuals are better adapted to survive
• and so produce more healthy offspring
• the environment selects which individuals pass on their alleles to the next generation

Question 3

theory of evolution in modern biology

Answer 3

• helps to understand relationships between different organisms
• explains how new species evolve
  explains how species adapt to their environmnet

Question 4

Darwin’s theory of evolution

Answer 4

1. adults produce more offspring than the environment can support
2. individuals with not as well adapted variations are less likely to survive, no offspring
3. individuals with advantageous variations in characteristics adapted to the environment, better chance of surviving to adulthood
4. more individuals will have advantageous variations in future generations

Question 5

k
p
c
o
f
g
s

Answer 5

kingdom - animal
phylum - vertebrate 
class - mammal
order - carnivorous
family - cat
genus - big cat
species - lion

Question 6

what are the five kingdoms

Answer 6

Plants
Animals
Fungi
Protists
Prokaryotes

Question 7

3 domain system

Answer 7

prokaryotes divided into eubacteria and archaea (bacteria living in salty/warm conditions)
genes of organism in Archaea work like eukaryotes, while genes in organisms of eubacteria work differently

Question 8

list human evolution

Answer 8

Ardipithecus ramidus (Ardi) -4.4 mil. years ago, tree climber
Australopithecus afarensis (Lucy) - 3.2 mil. years ago, ape-like face
Homo Habilis - 2.4-1.4 mil. years ago, modern face, stone tools
Homo erectus - 1.8-0.5 mil. years ago, long distance walker, strongly built
Homo sapiens (modern humans) - since 200 000 years ago, user of complex tools

Question 9

when are the earliest stone tools from

Answer 9

2.4 million years old, over time a range of tool types were made
tools became sharper rather than flat

Question 10

selective breeding

Answer 10

plants or animals with certain desirable characteristics are chosen to breed together for offspring to inherit these characteristics. Produces new breeds and varieties

Question 11

stages of selective breeding in plants

Answer 11

• plants with good features are crossed e.g. good yield
• plants grown for these crosses are selected for good features then crossed with each other
• repeated until a high yielding variety is produced

Question 12

reason for/against selective breeding

Answer 12

For
- disease resistance
- increased yield
-better ability to cope with conditions
- faster growth
- batter flavour
Against
- immoral
- can cause interbreeding

Question 13

genetic engineering is

Answer 13

changing the genome (DNA) of an organism by introducing genes from another organism.

Question 14

how genetic engineering works

Answer 14

1. the gene for a characteristic is ‘cut out’ of a chromosome using enzymes
2. the gene inserted into a chromosome in the nucleus of another organis3. the cell of this organism now produces the characteristic from the gene

Question 15

GM crops

Answer 15

plants genetically modified for characteristics such as:

• resistance to attack by insects
• resistance to herbicides, so field can be sprayed to kill insects not crop

Question 16

how is human insulin made from genetic engineering

Answer 16

1. DNA from a human cell is cut up using restriction enzymes, which leaves unpaired bases at the end (sticky ends)
2. bacteria contain circles of DNA called plasmids, these are cut up by restriction enzymes, leaving matching sets of unpaired bases
3. The DNA bases containing the insulin gene are paired with the plasmid bases, DNA ligase (enzyme) is added, linking the DNA back into a continuous circle
4. plasmids inserted into bacteria, bacteria is grown in huge fermenters, where they make human insulin.