Natural Selection and GM

Question 1

Why do phenotypes vary between species

Answer 1

-differences in alleles
-how the environment affects the individual
-combined effects of allele and environment

Question 2

what is continuous variation

Answer 2

where the characteristic can take any value (length,mass,etc) ,visualised with a line graph

Question 3

what is discontinous variation

Answer 3

where the characteristic can only have a limited set of values in a data set (blood group/eye colour),visualised with a bar chart

Question 4

how can fossil be dated

Answer 4

stratigraphy
radiometric dating

Question 4

what is a fossil

Answer 4

trace of an animal which lived millions of years ago

Question 5

what is stratigraphy

Answer 5

study of rock within which fossils are found, older rocks are in the lower layers

Question 6

What does the pentadactyl limb suggest

Answer 6

that many modern day vertebrates have descended from one ancestor

Question 7

what did carl linneaus do

Answer 7

divided organisms into groups based on what they look like
-used the last 2 groups(genus+species) to give each organism its binomial species name

Question 8

Ardi

Answer 8

time period alive: 4.4million yrs ago
opposable big toe
bipedae-walked upright
swinging arms(not using arms for swinging)

Question 9

Lucy

Answer 9

• time period: 3.9-2.9 million years ago
• hands well suited for camoflage manipulation of objects
• ape-like features

Question 10

what are the 5 kingdoms

Answer 10

animals, plants, fungi, protista, prokaryotes

Question 11

what are the characteristics of animals

Answer 11

-eukaryotes
-heterotrophic feeders, no chlorophyll, can’t do photosynthesis
-no cell walls

Question 12

what are the characteristics of plants

Answer 12

eukaryotes
cell walls made of cellulose
autotrophic feeders, use chlorophyll

Question 13

what are the characteristics of fungi

Answer 13

mostly eukaryotes
cell walls made of chitin
decomposers

Question 14

what are the characteristics of protista

Answer 14

mostly prokaryotes
complex cell structure with a nucleus

Question 14

what are the characteristics of prokaryotes

Answer 14

unicellular
no nucleus
simple cell structure

Question 15

what is the classification ladder

Answer 15

kingdom,phyllus,class,order,family,genus,species

Question 16

what are the 3 domains

Answer 16

bacteria, archea, eukarya

Question 17

what is selective breeding

Answer 17

when humans only breed from selected individuals in order to preserve and replicate their characteristics

Question 18

what is a clone

Answer 18

an organism that is an exact genetic copy of another organism

Question 19

what are the steps of micropropagation in plants

Answer 19

-small pieces cut from the tips/stems of plants
-these are called explants
-they are placed in an artifical growth medium containing nutrients and growth hormones
-they grow into genetically identical clones

Question 20

what are the advantages of tissue culture in plant breeding

Answer 20

-helps preserve endangered plant cell
-efficient(lots of plants created quickly with desired characteristics)
-only have to do GM once
-helps to grow plants that cant grow easily with seeds

Question 21

disadvantages of tissue culture

Answer 21

all susceptible to the same attack/diseases/pests
-smaller gene pool=no evolutionary potential

Question 22

how can we use tissue culture for medical research

Answer 22

-can create whole organs without worrying about lack of donors
-don’t need to use immunosuppressants

Question 22

what are the animal tissue culture steps

Answer 22

-cells extracted from the animal -separated using enzymes -grown in culture vessels containing nutrient agar or liquid nutrient broth -vessels are incubated for a period of time,optimum pH,temp=present, O2 also needed for aerobic respiration

Question 23

what is genetic engineering

Answer 23

transfer of a gene from the genome of one organism to the genome of another -can be done to introduce a desirable characteristic, much faster than selective breeding

Question 27

What are the steps for genetic engineering

Answer 27

Plasmid vector removed from bacterium Endonuclease enzyme cuts open the plasmid DNA to produce uneven “sticky ends” because the cut is staggered meaning that one of the DNA strands had unpaired bases The same restriction enzyme is used to cut out the gene we want, because they are left with complimentary sticky ends DNA Ligase enzyme joins the sticky ends together to make recombinant DNA The recombinant DNA is inserted into the bacteria which has now become a GMO The transgenic GM bacteria divides to produce millions which all make the protein we want

Question 28

What are the concerns behind genetic engineering

Answer 28

Many modified embryos don’t survive GM animals have health issues GM organisms may pose health risks to humans when consumed GM crops could cross pollinate with wild plants, spreading the DNA through the ecosystems GM crops are often expensive

Question 29

BT crops

Answer 29

They are produced because they kill insects and larvae that are harmful to crops so that the crop is resistant to the larvae

Question 30

What are the methods of genetically modifying eukaryotic cells

Answer 30

Bacterium that can infect plant cells A gene gun

Question 31

Why is herbicide resistance in crops good

Answer 31

Herbicide can be sprayed on the whole crop farm instead of spraying each weed

Question 32

Why is herbicide resistance bad

Answer 32

Some weeds could get pollinated from the crops and then become a super weed and become resistant to the herbicide

Question 33

What is biological pest control

Answer 33

When you use an organism to control a pest Can be a predator,parasite,pathogen

Question 34

What are the advantages of biological pest control

Answer 34

Cheaper than pesticides as you don’t have to put them again Less danger of impact on the environment and water quality

Question 35

What are some disadvantages of biological pest control

Answer 35

More management and planning Takes more time than pesticides