evolution

Question 1

biological evolution

Answer 1

• any genetic change in a population that is inherited over several generations
• shows that all life forms on earth have a common ancestor

Question 2

mutation

Answer 2

• genetic mutation is the ultimate source of variation

- genetic mutation occurs due to errors in replication

Question 3

sexual recombination

Answer 3

• genes are shuffled due to sexual recombination
• when 2 organisms reproduce, the offspring have a combination of both their genes. these changes can lead to different characteristics

Question 4

evolution

Answer 4

• is a scientific theory that is heavily supported by evidence proposed by Charles Darwin in 1859
• refers to change in a population’s gene pool over time
• evolution only occurs on a larger scale

Question 5

variation

Answer 5

term used to describe all the genetic differences that exist in a species
- all species show variation

Question 6

selective pressure

Answer 6

is what causes the gene pool of a population to change

- selection is the process of organism striving or struggling (low/high fitness)

Question 7

heredity

Answer 7

• not all organism survive the struggle
• those who do survive have features that give them an advantage that help them adapt to the environment
• the advantageous genes are passed on the future generations
• over time the species population becomes more adapted to the environment

Question 8

species

Answer 8

collection of organisms that retain the ability to reproduce with each other

Question 9

speciation

Answer 9

refers to the formation of new and distant species as a result of natural selection
- occurs from isolation

Question 10

isolation

Answer 10

• speciation generally only occurs as a result of isolation
• when a species remains together genetic shuffling occurs and the development of a new species
• when separated, genetic differences can increase to the point where 2 populations can no longer reproduce

Question 11

homology

Answer 11

• some organism have features with a similar structure but have different functions
• bats, cats, whales and humans all have the same forelimb structure
• this suggests a recent common ancestor

Question 12

relative dating

Answer 12

• evidence for evolution
• the deeper the layer, the older the rock
• each layer contains fossils that are from that specific period of time

Question 13

fossils

Answer 13

• evidence for evolution
• the preserved remains or traces of a once-living organism
• looking at the age of the fossil we can see that organisms have become more complex over time

Question 14

embryology

Answer 14

• evidence for evolution
• embryology shows us that organisms have very similar prenatal development
• suggest common ancestor

Question 15

vestigial organs

Answer 15

• structure that no longer has a useful function

Question 16

comparative study of DNA

Answer 16

• evidence for evolution
• more similar the sequence, the more recent the common ancestor was
• differences in sequences come from mutations

Question 17

geographic distribution

Answer 17

• evidence for evolution
• organisms in different locations are similar in many ways due to a common ancestor but have developed different characteristics to suit the environment of the location

Question 18

vestigal organs EFE?

Answer 18

• V.O indicate the idea of change over time
• evolution is not a perfect process and organisms maintain some of the features of their ancestors despite them no longer having a function

Question 19

comparative study amino acids in protein

Answer 19

• evidence for evolution
• the more similar the amino acids in the proteins, the more closely related the species
• share a common ancestor