Natural Selection and GM

Question 1

what were the first organisms on earth like

Answer 1

simple and single celled (unicellular)

Question 2

how many species do we estimate are on this planet

Answer 2

10 million

Question 3

what is evolution

Answer 3

the change of an organisms characteristics over generations

Question 4

what is the most widely accepted theory of evolution

Answer 4

the theory of evolution by natural selection from Charles Darwin

Question 5

what is the theory of natural selection

Answer 5

1. individuals in a population show genetic variation, caused by different alleles arriving through mutations
2. selection pressures affect an organisms chance of surviving and reproduction
3. individuals with characteristics suited to selection pressures are more likely to survive and breed successfully
4. these successful alleles are more likely to be passed on and become more common in the population over time

Question 6

selection pressure

Answer 6

things like predation, competition for resources, disease etc.

Question 7

alleles

Answer 7

different forms of the same gene

Question 8

mutation

Answer 8

rare, random change in gene/chromosome

Question 9

what did charles darwin do

Answer 9

spent 5 years on hms beagle, noticed variation in individuals of same species and those with characteristics most suited to the environment were more likely to survive with characteristics passed on to offspring.
published his theory of evolution by natural selection in 1859 in origin of species

Question 10

what did alfred russel wallace do

Answer 10

worked at same time as darwin. also came up with nautral selection indepent of darwin, both published papers on evolution together, acknowledged each others work. Wallace’s observations provided lots of evidence to support this theory

Question 11

how does antibiotic resistance in bacteria support darwins theory of evolution

Answer 11

example of natural selection taking place.

Question 12

what are the 2 ways fossils can be dated

Answer 12

stratigraphy and through radiometric dating

Question 13

stratigraphy

Answer 13

study of rock layers within which fossils are found. Older fossils usually in the lower rock layers

Question 14

radiometric dating

Answer 14

method of dating rocks using radioactive isotopes, usually potassium-argon.

Question 15

why are fossils useful as evidence for evolution

Answer 15

they are a trace of an organism that lived many years ago, and by arranging them in chronological order, gradual changes can be observed

Question 16

what is a pentadactyl limb

Answer 16

a limb with 5 digits

Question 17

how does the pentadactyl limb show evidence for evolution

Answer 17

many modern day vertebrates have a complete pentadactyl with the same bone structure, it makes it likely that they all evolved from a common ancestor

Question 18

anatomy of a pentadactyl ling

Answer 18

humerus at the top, radius on left, ulna right, carpal underneath radius and ulna, phalanges on bottom

Question 19

5 kingdoms in classification

Answer 19

animals, plants, fungi, prokaryotes, protists

Question 20

classification ladder

Answer 20

kingdom
phylum
class
order
family
genus
species

Question 21

what did Carl Linnaeus do

Answer 21

published classification system in 1735. used genus and species to give organism its binomial name

Question 22

what did Carl Woese find

Answer 22

using rna sequencing, he found out that some members of prokaryotes were not as closely related, and split the kingdom into 2 groups called Bacteria and Archae, and changed the classification system into 3 domains

Question 23

3 domain classification system

Answer 23

Eukarya, Archaea, Bacteria are 3 domains, then subdivided into classification ladder.

Question 24

why are dna sequences useful

Answer 24

scientists can compare organisms dna sequence to compare relationships between organisms.

Question 25

selective breeding

Answer 25

humans selecting individuals with deisirable features that they want to enhance to breed, takes many generations

Question 26

disadvantages of selective breeding

Answer 26

creates disease, reduces gene pool, offspring less likely to recieve beneficial alleles and cannot evolve.

Question 27

problems of inbreeding

Answer 27

greater chance of harmful genetic defects, ethical issues, increases susceptibility to disease.

Question 28

how does selective breeding differ from natural selection

Answer 28

in natural selection, organisms with characteristics suited to its environment survive and reproduce, whereas selective breeding is chosen by humans for features they want. natural selection is random, selective breeding is based off humans choice

Question 29

uses of selective breeding

Answer 29

increase crop yields or livestock produce.

Question 30

what happens if a disease appears in an inbred population

Answer 30

not much variation with reduced gene pool, so less chance of resistant alleles. If one is killed, others are likely to succumb to it

Question 31

what species was lucy

Answer 31

Australopithecus afarensis