Evolution , Variation &adaptation

Question 1

Natural selection

Answer 1

The process by which organisms best suited to their environment survive and reproduce passing On their characteristics to their offspring through genes

Question 2

Darwin

Answer 2

Born in 1809
Most people believed god created everything
Finches t

Question 3

What observations and analysis did Darwin make

Answer 3

Offspring generally resemble their parents - characteristics passed onto their next generation

No 2 individuals are identical - there’s a variety of organisms= !many changes/mutations may give rise to a new species therefore individual characterises survive

Organisms have the ability to produce larger numbers of offspring yet populations remain a stable size - STruggle for existence

Question 4

Darwauns finches

Answer 4

Different finches in different islands in the Galápagos Islands and different to mainland

Varied in beak type - specialised for environment they lived in

Natural selection

Question 5

Interspecific variation

Answer 5

Variation between members of different species

Question 6

Intra specific variation

Answer 6

Variation between organisms WITHIN a species

Question 7

Causes of variation

Answer 7

Generic and evvironmental

Question 8

Genetic causss of variation

Answer 8

Mutations - changes to the DNA sequence and therefore the genes that code for proteins , can be physical or metabolic - if a mutation occurs in gametes = offspring

Meiosis - gametes produced, independent assortment and crossing over

Sexual reproduction - genes from 2 parents

Chance - due to chance ( which 2 gametes join )

Alleles - genes have different alleles. with a gene for a particular characteristic , different alleles produce different effects. different VERSIONS of alleles

Question 9

Environmental causes of variation

Answer 9

All organisms affected by the environment which they live in

Eg scars

Question 10

Environmental and genetic variation - both

Answer 10

COMBINATION

Height for example - fall parents and diet

Skin colour - parents and sunlight

Question 11

What is variation

Answer 11

Differences between organisms characteristics

Question 12

Discontinuous variation

Answer 12

A characteristic that can only result in certain values 
No inbetween values 
Discrete categories without intermediates
No environmental influences 
Effect of few genes
QualiTive data 
Bad chart 
Eg animal sex - male or female

Question 13

Continuous variation

Answer 13

No distinct groups

Many intermediate species
Btoh environment and usually many genes influence

Quantative

Height

Question 14

Distribution curves

Answer 14

Characteristics of normal distribution =

• mean , mode and median the same
• the distribution has a characteristic ‘ bell shaped ‘ that symmetrical about the mean
• 50% of rates are less than mean and 50% greater
• most values lie close of the mean value - the number of individuals at extremes are low

Question 15

Standard deviation

Answer 15

Measure of how spread out the data is

Greater standard deviation = larger spread = larger variation

Question 16

Statistical tests w

Answer 16

!!!!!

Question 17

What is adaptation

Answer 17

Characteristics that increase an organisms chance of survival and reproduction

Question 18

Anatomical adaptation

Answer 18

Physical features ( internal and external )

Question 19

Behavioural adaptation

Answer 19

They way an organism acts , can be inherited or learnt from parents

Question 20

Physiological adapatation ? What

Answer 20

Processes that take place inside an organism

Question 21

Anatomical adaptations - examples

Answer 21

Body covering - eg hair, scale to spines, These can help and organism to fly or stay warm= provide protection , prevent waterloss

Camoglagu

Teeth - shape& type related to diet

Mimicry - copying another animals appearance of sounds ( harmless organism can fool predators )think they’re dangerous

Question 22

Behavioural adaptations examples

Answer 22

Survival - playing dead
Coorship_ bahaviourals to attract a mate eg dance
Seasonal behaviours- allow an organism to cope with changes to environment

Migration- animals move from one region to another and back when environmental conditions are more favourable

Hibernation - heart rate , breathing and body temp slow down = conserving energy reducing requirements for food

Question 23

Types of behavioural adaptations

Answer 23

Innate ( instinctive ) = genes

Leaned behavioural - learnt from experience or ?? from toher animals

Many are combo of both

Question 24

Physiological adapatations

Answer 24

Poison production

Antibiotic production

Water holding

Reflexes , blinking , temp regulation

Question 25

How does anatomical adapatation provide evidence for convergent evolution

Answer 25

Unrelated species begin to share similar traits These similarities evolve because the organisms adapt to similar environments or other selection or other selection pressures

Question 26

What does analogous structure mean

Answer 26

Performing same role But different structures Adapted to perform the same function but have different origin Eg fin of whale and fishb perform SAME role - different structures

Question 27

Placental mammals

Answer 27

Placenta connects the embryo to its mothers circulatory system in the uterus , this nourishes the embryo

Question 28

Marsupial mammals

Answer 28

Start life in the uterus then leave and enter the marsupium ( pouch)while stil embryos, they complete development by suckling milk

Question 29

Simularities of marsupial and placental moles

Answer 29

Short and powerful limbs, huge front claws, no edxternal ears, limited eyesight Both have streamlined, velvet fur

Question 30

Differences of marsupial and placental moles

Answer 30

M have a hood area on front of its head. Placental has a thin snout, marsupial has a fused neck vertabrae M are white- orange , placental is grey

Question 31

What are seletion pressures

Answer 31

Factors that affect an organisms chance of survival or reproductive success ORganisms best adapted to their enviornemnt are more likely to survive and reproduce

Question 32

Steps of evolving and natural selection

Answer 32

1. Organisms within a species show variation, their characterstics that are caused by differences in their genes ( genetic variation) 2. Organisms best adapted to a sleection pressure survive- survival of the fittest 3. successful organisms pass the allele encoding the advantageoys characteristics nto thier offspring. Organisms wiht non adventogeous gene are less likely to pass it on 4. repeated every generation, over time the advantageous adaptation proportion increases. Frequency ncreases in populations gene poo l 5. OVer time =evolutin of new speceis

Question 33

Antibiotic resistance

Answer 33

Bacteria, few resistant Bathed in antibiotics Weak die adnd resitant bacteria mutiply, eventually all resistant e.g.mrsa - ressitant to methicillin

Question 34

pepper moths

Answer 34

in the 19th centuary - industlisation meant that plants turned black adn darker, moths changed from white to balck THose that were black died

Question 35

Pesticide resistance

Answer 35

Same pricipal as antibitoic resistance -but for insects e.g. in 1950s, australia, pesticide used to kill sheep blwofies, within 6 years they developed rsistance. Pre adaptation=pre esiting advantage

Question 36

reducing chance of pesticide resistance

Answer 36

Mixing 2 together to etend time for ressitance to emerge GM Reduce use of presticides Only use for breakout now invasion

Question 37

bacteria evolution

Answer 37

One strand of Flavobacterium - opportunities arisen, live in waste wter from factories hat produce nylon 6 Strain can digest it = nutrients