Classification And Evolution

Question 1

What is classification

Answer 1

Putting things into groups

Question 2

What is taxonomy

Answer 2

Is the science of systematic classification
- classes organisms in taxa

Question 3

What are the 8 taxas

Answer 3

-domain
-kingdom
-phylum
-class
-order
-family
-genus
-species

Question 4

What is phylogeny

Answer 4

The study of evolutionary relationships

Question 5

Phylogenetic classification

Answer 5

Reflects evolutionary relationships
-more closely related 2 organisms are the more and smaller taxa they share

Question 6

What are the 5 kingdoms

Answer 6

Prokaryota, protoctista, fungi, plant and animal

Question 7

What is the Scientific naming of a species

Answer 7

-Binomial name (which includes:)
Genus name (capital letters)
Unique species name (lowercase)

Question 8

What are the 2 rues for handwriting and typing species name

Answer 8

In handwriting- must be underlined
In typing- must be in italics

Question 9

How were kingdoms found

Answer 9

-better microscopes
-biochemistry

Question 10

Who was the 3 domain system proposed by and what is it for

Answer 10

Carl woese
- classifies organisms on the basis of differences in there rRNA
-allows to see differences between any 2 organisms

Question 11

What are the 3 domains

Answer 11

-archae
-bacteria
-eucarya

Question 12

What are the reasons behind the 3 domain system

Answer 12

-bacteria and archaea are fundamentally different
-archaea is more similar to eukaryotes than bacteria
- they have different cell membranes and flagella structures and different enzymes for synthesising RNA

Question 13

What is the problem with classifying organisms by characteristics

Answer 13

Convergent evolution
- 2 unrelated species could adapt to the same environment so look similar

Question 14

What is cytochrome C and what is it for

Answer 14

Haem protein found in mitochondria
- is small sequence of amino acids
- if sequence is similar 2 organisms are closely related
- the more differences found the less closely related

Question 15

An example of amino acid sequence found in cytochrome c

Answer 15

It is identical for humans and chimpanzees (so more closely related together)

Question 16

What is DNA and what is it for

Answer 16

-Found in all living organisms
-Provides genetic code
-The more similar the sequence the more closely related the species

Question 17

What is variation

Answer 17

Differences that occur within same species and between different species

Question 18

What are the 2 types of variation

Answer 18

Interspecific- between species
Intraspecific- within same species

Question 19

What are the 2 causes of variation within a species

Answer 19

Genetic variation- caused by differences between individual genes (can be passed onto offspring)

Environmental variation- brought by the influence of the environment on the way they grow and develop (cannot be inherited)

*evolution only concerned with genetic variation.

Question 20

What are the sources of genetic variation

Answer 20

Independent assortment!
-random fertilisation gives new combinations of alleles

Mutations:
-may create new alleles
-is heritable
-mutations in gamete forming cells are passed onto offspring

Question 21

What is continuous variation

Answer 21

Individuals showing gradual change from one to another with no distinct types

Question 22

How is continuous variation done

Answer 22

-It’s polygenic
-By the interaction of many different genes
-Huge number of different allele combinations

Question 23

What is discontinuous variation

Answer 23

When individuals are clearly divided into distinct types with no overlapping or merging

Question 24

How is discontinuous variation done

Answer 24

-Small number of different alleles combinations
-Affected by one of few genes

Question 25

What is adaptation

Answer 25

Any variation that helps an organism survive

Question 26

What are the 3 different types of adaptations

Answer 26

-anatomical- structure of organisms -behavioural- behaviour enhancing survival -physiological- biochemistry- function of cell processes

Question 27

Give anatomical adaptations of marram grass

Answer 27

~long roots- plant can reach underground ~leaves are curled- reduces SA exposed to wind so moisture can build up inside ~waxy cuticle- reduces evaporation of water ~lower epidermis covered in hair- air movement reduced so water stays inside

Question 28

Give behavioural adaptations of marram grass

Answer 28

~When covered by sand it grows more quickly to reach sunlight ~responds to water shortage by rolling leaf more tightly

Question 29

Physiological adaptations of marram grass

Answer 29

~ has many lignified cells to provide support when water is not available ~ can survive in salty conditions so maintains cell water potential lower than other plants

Question 30

Behavioural adaptation of earthworm

Answer 30

Quickly contracts when touched and goes back into burrow- has no eyes

Question 31

What are Darwin’s observations

Answer 31

- all living organisms over produce -organism within a species vary - some of these variations are inherited

Question 32

Overproduction

Answer 32

Environmental factors can keep numbers down these may be biotic or abiotic

Question 33

What is biotic factors and give examples

Answer 33

Living organisms E,g - predators, prey animals

Question 34

What is abiotic factors and give examples

Answer 34

Non living factors E.g sunlight, water, grass

Question 35

What is selection pressure

Answer 35

Evolutionary force that causes a particular organism to be more favourable in certain environmental conditions

Question 36

E.g of selection pressure

Answer 36

Predation of foxes -increases chance of variation being passed onto offspring and decreases chance of others -this is natural selection -organisms with best adapted characteristics will pass it down

Question 37

How does natural selection occur

Answer 37

- mutation in allele -causes intraspecific variation -when resources are scarce in environment selection pressure occurs -advantageous individuals survive -they pass on these characteristics and next generation has successful traits

Question 38

What is a species

Answer 38

Group of organisms that can interbreed producing fertile offspring

Question 39

What is Speciation

Answer 39

Formation of a new species

Question 40

What is needed for speciation to occur

Answer 40

Populations must be isolated from each other

Question 41

What is Allopatric speciation

Answer 41

Population becomes separated form the rest by a geographical or physical barrier

Question 42

What does differing selection pressure do to separate populations

Answer 42

Makes them genetically different so can’t breed with each other again

Question 43

What is sympatric speciation

Answer 43

When populations become separate by reproductive barriers

Question 44

Give 2 evidence for evolution

Answer 44

-fossils ~ shows old species and new risen ones -biological molecules ~2 closely related species will have similar bio molecules and would’ve separated only recently