Classification & evolution

Question 1

Name the 7 seven taxonomic groups

Answer 1

Kingdom, Phylum, class, order, family, genus, species

Question 2

give 3 reasons scientists classify organisms

Answer 2

• to identify species
• the predict characteristics
• the find evolutionary links

Question 3

name the 3 domains

Answer 3

Archaea (fungi), prokaryote, eukarya (animals, plants)

Question 4

Name the 5 kingdoms

Answer 4

Animalia, Plantae, Protoctists, Prokaryote, Fungi

Question 5

How is a species defined?

Answer 5

A group of organisms that can reproduce to produce fertile offspring

Question 6

name the naming system for organisms

Answer 6

binomial nomenclature (Genus, species)

Question 7

What are Archaebacteria?

Answer 7

they live in extreme environments such as; hot vents, anaerobic conditions and highly acidic conditions

Question 8

Where is Eubacteria?

Answer 8

‘true bacteria’ - found in all environments

Question 9

General features of Animalia

Answer 9

• multicellular
• nucleus and other membrane-bound organelles
• no chloroplasts
• move with aid of cilia, flagella or contractile proteins

Question 10

General features of Plantae

Answer 10

• multicellular
• a nucleus and other membrane bound organelles (including chloroplasts)
• all contain chlorophyll
• do not move, but gametes move using flagella or cilia
• nutrients acquired by photosynthesis - AUTOTROPHIC FEEDERS
• store starch
• cell wall composed of cellulose

Question 11

General features of Fungi

Answer 11

• uni or multicellular
• cell wall composed of chitin
• no mechanisms of locomotion
• body or mycelium made of threads or hyphae
• nutrients acquired by absorption from decaying material - SAPROPHYTIC FEEDERS
• store food as glycogen

Question 12

General features of protocists

Answer 12

• mainly unicellular
• a nucleus and other membrane bound organelles
• some have chloroplasts
• some are sessile, but some move my cilia or flagella
• nutrients absorbed by photosynthesis, ingestion of other organisms, or both

Question 13

General features of prokaryotes

Answer 13

• Unicellular
• no nucleus only a ring of naked DNA
• smal ribosomes
• no visible feeding mechanism - nutrients absorbed through cell wall

Question 14

What is phylogeny?

Answer 14

the evolutionary relationship between animals - the study of this is called phylogenetics

Question 15

an advantage of phylogeny

Answer 15

• produces a more continuous tree whereas classification requires discrete taxonomical groups - this means scientists do not have to put organisms into a specific group in which they do not quite fit

Question 16

Name some evidence for evolution

Answer 16

• palaeontology - study of fossils
• comparative anatomy - study of similarities and differences between organism (e.g pentadactyl limbs)
• comparative biochemistry - similarities and differences between the chemical makeup of organisms

Question 17

Problems with palaeontology

Answer 17

• conditions for fossils to form are often not present
• the fossil record is incomplete
• many organisms are soft-bodied and decompose quickly
• fossils are often damaged by the earth’s movements

Question 18

define Comparative anatomy - homologous structure

Answer 18

structure that appears scientifically different in different organisms but has the same underlying/basic structure (pentadactyl limb)

Question 19

define Divergent evolution

Answer 19

from a common ancestor, different species have evolved, each with a different set of adaptive features (why new species from from loss of habitat or migration to new habitats)

Question 20

define Comparative biochemistry

Answer 20

study of similarities and differences in the proteins and other molecules that control life processes (although they change overtime there are many that should remain unchanged due to lack of need for adaptation)

Question 21

What is variation?

Answer 21

the difference in characteristics between organisms

Question 22

what is Intraspecific variation

Answer 22

difference between organisms within a species

Question 23

Give examples of intraspecific variation

Answer 23

varying in height, build, eye and hair colour and intelligence

Question 24

what are the main causes of variation

Answer 24

• organisms genetic material (differences lead to geneti variation)
• the environment in which an organism lives - causes environmental variation

Question 25

give the genetic causes of variation

Answer 25

- alleles (alternative forms of a genes) - mutations (changes to the DNA sequence and therefore the genes can lead to changes in the proteins that are coded for) - meiosis - independent assortment and crossing over during creation of gametes - sexual reproduction - the offspring of parents are different from the parents as they inherit alleles from both - chance - many different genes are produced from the same parental genome - it is by chance which two combine

Question 26

an example of environmental causes of variation

Answer 26

- scars on a body can only be caused by the environment and cannot be inherited from parents - skin colour can vary dependant on spending a lot of time in the sun (skin colour at birth is purely genetic)

Question 27

why would the environment cause greater variation in plants than animals

Answer 27

plants cannot move to adapt to the environment and so must variate to survive (e.g a plant that gets covered by shade will adapt to need less sunlight that the one that is in the sun constantly - animals can move to adapt to their food/shelter needs)

Question 28

What is discontinuous variation and give an example

Answer 28

a characteristic that can only result in certain values e.g eye colour, hair colour these are variations that are only a result of genetics

Question 29

What is continuous variation and give an example

Answer 29

a characteristic that can take any value within a range (there is a graduation of values) these characteristics are said to be polygenic as they are determined by more than one gene and can also be influenced by environmental factors

Question 30

What is student's t-test used for?

Answer 30

Used to compare the means of data values of two populations

Question 31

What is Spearman's rank used for?

Answer 31

used to consider the relationship between two sets of data (if two sets of data are related they are said to be correlated)

Question 32

What is an adaptation?

Answer 32

characteristics that increase an organisms chance of survival and reproduction in its environment

Question 33

Give types of adaptations

Answer 33

- anatomical adaptations: physical features - behavioural adaptations: the way the organism acts (can be inherited or learnt from parents) - physiological adaptations: processed that take place inside an organism

Question 34

Give examples of anatomical adaptations

Answer 34

- body covering: hair, scales, spines, feathers, shells (can help the organism (e.g wavy cuticle on a plant helps it conserve water) - camouflage: outer layer of an organism allows it to blend into its environment (e.g snowshoe hair is white to blend into snow) - teeth: shape and type of teeth are adapted to the food the organism eats (e.g carnivores have canines to kill prey) - mimicry: copying another animals appearance or sounds allow a harmless organism to fool predators into thinking it is dangerous (e.g hoverfly mimics the markings of a wasp)

Question 35

What is Marram grass and how is it adapted to its environment?

Answer 35

it is a xerophyte found on sand dunes around the UK - it has adapted to retain as much water as possible: - curled leaves so stomata face each other - hairs on inside surface of the leaves trap moist air close to the leaf - thick waxy cuticle on leaves and stems which reduces water loss

Question 36

Give examples of behavioural adaptations

Answer 36

- survival behaviours: rabbit freezes when they think they have been seen - courtship: to attract a mate (scorpions perform a dance) - seasonal behaviours: allow organisms to cope with changes in their environment (migration, usually to a warmer area or more food. hibernation, period of inactivity where energy is conserved usually throughout winter)

Question 37

give examples of physiological adaptations

Answer 37

- poison production: reptiles produce venom to kill their prey and plants produce poison to stop themselves being eaten - antibiotic production: some bacteria produce antibiotics to kill other types of bacteria in the area - water holding: allows organisms to survive for long periods without water

Question 38

What are selection pressures?

Answer 38

factors that affect the organism's chances of survival or reproductive success

Question 39

How does natural selection occur?

Answer 39

1. Organisms within a species show variation in their genes 2. Those that have become better adapted to a selection pressure will have an increased chance of survival 3. Successful organisms pass on the alleles coding for the advantageous characteristics 4. Process is repeated for every generation 5. over very long periods of time this process can lead to evolution

Question 40

Modern example of evolution: antibiotic resistant bacteria

Answer 40

Anti-biotic resistant bacteria (MRSA) has developed a resistance to many different antibiotics - a mutation arose in some of the bacteria providing resistance to methicillin.

Question 41

Modern example of evolution: peppered moths

Answer 41

Peppered moths - loss of lichen covering trees and increased pollution meant that trees became darker. Suddenly the darker moths were more suited to the environment than the pale ones and so this characteristic became more frequent.

Question 42

Flavobacterium - evolution

Answer 42

One of the few organisms that has evolved due to opportunities that have arisen in their environment - they live in waste water from factories that use nylon 6. Flavobacterium have developed to be able to digest nylon (with nylonases) and are therefore beneficial to humans as they clear up waste.