classification (finished)

Question 1

what is the hierarchy of taxon’s?

Answer 1

Kingdom, Phylum, Class, Order, Family, Genus, Species

Question 2

what is the tentative nature of classification?

Answer 2

Classification can change overtime as additional information becomes available.

Question 3

Describe a Prokaryotae

Answer 3

• unicellular
• 70s ribosomes
• cell wall of peptidoglycan
• contains membrane-bound organelles

Question 4

describe Plantae

Answer 4

• multicellular eukaryotes
• photosynthetic
• cellulose cell wall

Question 5

Describe Animalia

Answer 5

• nervous co-ordination
• multicellular eukaryotes
• no cell wall
• heterotrophic and holozoic

Question 6

Describe Fungi

Answer 6

• eukaryotes
• chitin cell wall
• heterotrophic and saprotrophic
• reproduce by spores

Question 7

Describe Protoctista

Answer 7

• unicellular eukaryotic organisms
• heterotrophic, autotrophic or both
• no tissue differentiation

Question 8

mnemonic for hierarchy of taxa (biggest to smallest)

Answer 8

King Philip Came Over For Good Soup

Question 9

What are the 3 Domains

Answer 9

Eubacteria, Archaea and Eukarya

Question 10

what evidence suggests that there are 3 domains?

Answer 10

studies of ribosomal RNA - evidence suggests all animals evolved along 3 separate lineages

Question 10

Why is classification described as having a tentative nature?

Answer 10

Classification is based on the information available at the time and is subject to change as new information comes to light.

Question 11

what are extremophiles?

Answer 11

bacteria that live where environmental conditions are harsh

Question 12

what is a species?

Answer 12

a group of organisms with similar characteristics that can interbreed to produce fertile offspring

Question 13

how can fertility in plants be assessed?

Answer 13

by seed production

Question 14

why can sterile hybrids not produce gametes?

Answer 14

the gametes of the two species have different chromosome numbers so therefore they cannot pair up at the start of meiosis

Question 14

what is the first name of the binomial name?

Answer 14

the genus (capitalised)

Question 15

what is the second name of the binomial name?

Answer 15

species name (lower case)

Question 16

why are binomial names universally adopted?

Answer 16

to avoid issues with local names and language differences

Question 17

what is a phylogenetic tree?

Answer 17

a diagram that represents the evolutionary pathways leading to different species

Question 18

what does the axis of a phylogenetic tree represent?

Answer 18

time

Question 19

what is a clade?

Answer 19

a group of branches from one common ancestor

Question 20

how can relatedness be established?

Answer 20

the sequences of subunits can be compared and the number of differences counted.

Question 21

why are there differences in DNA/RNA/protein sequences?

Answer 21

mutations in DNA can lead to differences in the amino acid sequence of proteins

Question 22

What is gel electrophoresis?

Answer 22

the separation of DNA and proteins by the gel

Question 23

How does the process of gel electrophoresis take place?

Answer 23

the gel allows small fragments to move further and the electrical charge causes movement of the negatively charged DNA fragments to the positive electrode. A banding pattern is produced which can be used for comparison.

Question 24

what is morphology?

Answer 24

looking at the shape and form of an organism

Question 25

what is a disadvantage of using morphology to classify organisms?

Answer 25

some organisms have similar morphology but are unrelated in evolutionary terms

Question 26

what is convergent evolution?

Answer 26

when selection pressures are similar and mutations giving rise to similar features provides an advantage

Question 27

what is an advantage of biochemical analysis like DNA sequencing?

Answer 27

it can overcome issues caused by convergent evolution

Question 28

what are homologous features?

Answer 28

features evolved from the same original structure for different structures e.g. pentadactyl limb

Question 29

what are analogous structures?

Answer 29

features that have evolved from different structures to form the same function e.g. wings of birds

Question 30

what do homologous features indicate?

Answer 30

that organisms are related

Question 31

how do analogous structures arise?

Answer 31

through convergent evolution

Question 32

what is biodiversity?

Answer 32

species richness and species evenness in a given area

Question 33

how does biodiversity on the planet vary?

Answer 33

spatially; increases going from the poles to the equator

Question 34

why does biodiversity increase towards the equator?

Answer 34

- more UV light causes higher rate of mutation so more rapid evolution - more species types > more habitats and niches - more stable temp. range + available water

Question 35

why is it difficult for species to move out of areas closer to the equator?

Answer 35

with more species, competition is high. this means more specialised and narrower exploitation of niches

Question 36

what is the fears regarding current human activities?

Answer 36

we are entering a 6th mass extinction event with a massive loss of biodiversity

Question 37

How is biodiversity in a habitat investigated?

Answer 37

species richness and species evenness must be counted

Question 38

what is species richness?

Answer 38

the number of different species

Question 39

what is species evenness?

Answer 39

the numbers of individuals of each species

Question 40

when can Gridding be used?

Answer 40

to compare two areas

Question 41

How can an area be sampled?

Answer 41

by gridding or sampling along a line (transect)

Question 42

when are transects used?

Answer 42

when there is a gradual change in the environment

Question 43

how can genetic biodiversity be assessed?

Answer 43

by determining the number of alleles at different loci within a given species - seeing what proportion of the population have that allele

Question 44

what is polymorphism?

Answer 44

the presence of several different forms or types of individuals among the members of a single species

Question 45

what does variation in DNA base sequences tell us?

Answer 45

the more variation, the higher the genetic biodiversity

Question 46

what are the steps in natural selection?

Answer 46

- mutations cause variation - overproduction of offspring lead to intraspecific selection - variation has selective advantage to survive selection pressure - survivors reproduce and pass on alleles

Question 47

what happens to the allele frequency overtime of the favorable variation?

Answer 47

it increases