topic five

Question 1

when does evolution occur

Answer 1

when heritable characteristics (allele) of a species change over time

Question 2

where do fossils typically form

Answer 2

in sedimentary rock, such as limestone and shale

Question 3

Heritable characteristics

Answer 3

the characteristics that an organism possesses due to its genetic make-up. These characteristics can be inherited by the organism’s offspring.

Question 4

macroevolution

Answer 4

occurs on a large scale leading to the development of new species.

Question 5

Fossils that show links between ancestral groups are known as

Answer 5

transitional

Question 6

Natural selection :

Answer 6

Natural selection occurs when species have variation and certain traits are selected because they help the species to reach a reproductive age and pass on their genes.

Question 7

Selective breeding :

Answer 7

A form of artificial selection in which organisms with certain characteristics are chosen by humans because they are of some benefit. These organisms are bred to produce offspring that have the same genes and, therefore, the same characteristics.

Question 8

breed

Answer 8

a group of animals within a species that have specific and similar characteristics.

Question 9

examples of selective breeding

Answer 9

Breeding egg-laying hens to lay lots of eggs
Breeding race horses for speed
Breeding dogs for herding, hunting or simply for specific physical features
Breeding cattle for increased meat or milk production
Breeding of crops to be disease- or cold-weather-resistant in order to increase production
Breeding of plants to produce larger and sweeter fruits.

Question 10

microevolution

Answer 10

occurs on a small scale within a species

Question 10

homologous

Answer 10

similar in position, structure, and evolutionary origin but not necessarily in function.

Question 11

Divergent evolution

Answer 11

when two separate species have a similar structure, but use it in different ways because of their environment.

Question 12

Pentadactyl limb

Answer 12

A limb with five digits, found in amphibians, reptiles, birds and mammals.

Question 13

Adaptive radiation

Answer 13

a process in which organisms rapidly diverge from the form of the original species into several new forms specialised to make use of different environmental niches. This can lead to divergent evolution and the development of a new species.

Question 14

Analogous:

Answer 14

performing a similar function but having a different evolutionary origin, such as the wings of insects and birds.

Question 15

convergent evolution

Answer 15

when organisms that are not closely related evolve similar structures that are used for similar purposes

Question 16

speciation

Answer 16

the process by which new species form, is one of the success stories of evolution.

Question 17

Discontinuous variation

Answer 17

a type of variation that is influenced by a gene or a few genes, can be put into categories, and is not influenced by the environment.

Question 18

Continuous variation

Answer 18

a type of variation that is controlled by many genes, has a wide range of variability, and is easily influenced by the environment.

Question 19

what happened in the 19th century

Answer 19

industrial revolution in the UK led to the widespread burning of fossil fuels by power machinery. This produced large amounts of sulfur dioxide in the atmosphere which killed many plants and lichen. It also produced vast quantities of soot which changed the colour of the tree bark. The result was darker coloured trees.

Question 20

in biston betularia, which allele is dominant

Answer 20

the dark allele. codes for the moth to make more melanin

Question 21

change in moth colours

Answer 21

industrial melanism
industry increase led to a change in the frequency of the alleles in the peppered-moth gene-pool.

Question 22

Transient polymorphism

Answer 22

the gradual change in the allele frequency of a population due to the slow replacement of one gene of another.

Question 23

balanced polymorphism

Answer 23

a balance between both forms of the allele variations within a population.

Question 24

causes oof variation

Answer 24

mutation meiosis sexual reproduction and random fertilisation

Question 25

what are missense mutations

Answer 25

may cause variation that benefits the organism by changing a codon, which in turn alters the protein.

Question 26

silent mutations

Answer 26

those in which the codon still codes for the same amino acid, so no actual change in the protein occurs. These silent mutations do not have any effect on the variation of the species.

Question 27

Examples of adaptations that have arisen through natural selection include:

Answer 27

Development of special hair structures in the fur coat of polar bears that insulate them from the intense cold of the Arctic and provide camouflage with the snow and ice. Development of intricate and subtle forms in orchids to entice certain insects to pollinate them, as well as the hairs on the insects that help to collect pollen, which they spread, helping to pollinate other plants of the same species, providing more genetic variation for the orchid.

Question 28

why was darwins finches a widely accepted theory

Answer 28

For a scientific theory to be accepted it must be able to explain and predict natural phenomena. The increase in the beak length and decrease in the beak width of these finches supports the theory of evolution by natural selection. Natural selection pressures caused adaptive radiation to occur where there were many small changes occurring in the species. This occurred until the species diverged and speciation arose.

Question 29

what do enzymes do to the beta lactam ring of penicillin and other antibiotics

Answer 29

break down the beta lactam ring

Question 30

why is antiobiotic resitnce spreading so widely and rapidly

Answer 30

Bacterial generation times are short, ranging from 20 minutes to several hours. This means that evolution can progress rapidly. There has been widespread use of antibiotics in the general population and in animal feed. People often do not finish a course of antibiotics, leaving residual populations of bacteria in their system that have been exposed and are likely to have developed partial or full resistance. Antibiotic resistance is often coded for by a gene or genes located on plasmids. The plasmids are easily exchanged between bacteria, even if they are not of the same species or strain. Hospitals are breeding grounds for antibiotic resistance, because that is where patients with severe infections are treated with high doses of antibiotics, creating enormous selective pressure on the bacteria.

Question 31

how is natural selection increasing antibitoic rsitance

Answer 31

When exposed to antibiotics, bacterial mutations can occur leading to more variation within the population. Those bacteria with variations that are resistant to the antibiotic are the most fit for their environment and will survive to pass on their resistant genes to their offspring or through plasmids. Those bacteria that are susceptible to the antibiotics will die. The allele for the antibiotic-resistant characteristic will increase in frequency in the gene pool and eventually, more and more bacteria become resistant.

Question 32

genus

Answer 32

a group of species that share common characteristics but may not be able to interbreed.

Question 33

species

Answer 33

a group of organisms in the same genus that are able to interbreed to produce fertile offspring.

Question 34

rules of writing the names of species

Answer 34

Genus name starts with a capital (upper case) letter. Species name starts with a lowercase letter. Genus name is always written before the species name. The complete name, i.e. genus and species, should be word processed in italics , or underlined when handwritten. Often genus and species names are written using Latin or classical Greek because they are unchanging languages, however there are many other sources of binomial names. The genus name is often abbreviated once it has been used in a text.

Question 35

what is taxonomy

Answer 35

branch od science concerned with naems

Question 36

the more taxa organisms share,

Answer 36

the more they have in common

Question 37

biological classification

Answer 37

Question 38

the highest level of classificatio is

Answer 38

a domain

Question 39

the three domains

Answer 39

Bacteria, Archaea and Eukaryota.

Question 40

bacteria

Answer 40

no histones Glycerol-esters of lipids, D-form of glycerol cell membranes peptidoglycan cell wall

Question 41

archaea

Answer 41

histones present in some species (similar to histones found in Eukaryota ) Glycerol-ether lipids, L-form of glycerol Not made of peptidoglycan cell wall

Question 42

eukayota

Answer 42

histones present Glycerol ester lipids, D-form of glycerol Not made of peptidoglycan, sometimes absent

Question 43

In the hierarchy of taxa, what is in a family?

Answer 43

A group of genera

Question 44

what is the best indicator for relatedness

Answer 44

nucleic acids

Question 45

6A dichotomous key is

Answer 45

a series of paired opposing statements which guide the user to the identity (or allows the classification) of an item or organism.

Question 46

four phyla

Answer 46

bryophytes, filicinophytes, coniferophytes and angiospermophytes

Question 47

bryophyta

Answer 47

No roots, leaves or stems reproduce Via spores NO vascularisation rhizoids as anchors moss

Question 48

filincophyta

Answer 48

roots, leaves and stems reproduce via spores vascularization pinnate leaves fern

Question 49

coniferophyta

Answer 49

roots, leaves and stems seeds in cones vascularization woody stem conifer

Question 50

angiospermophyta

Answer 50

roots, leaves and stems seeds from fruits vascularization produces flowers and fruits flowering plants

Question 51

Porifera

Answer 51

No symmetry 0 gut openings No segmentation Use spicules for support Sea sponge

Question 52

Cnidaria

Answer 52

Radial symmetry 1 gut opening No segmentation Cnidocytes (stinging cells) present Coral, jellyfish, hydra

Question 53

platyhelmintha

Answer 53

Bilateral symmetry 1 gut opening No symmetry Flattened body Tapeworm

Question 54

annelida

Answer 54

bilateral symmetry 2 gut opening segmentation use peristalsis for moving leech, earthworm

Question 55

mollusca

Answer 55

bilateral symmetry 2 gut openings non visible segmentation some have a shell made by mantle octopus, snail, slug, oyster

Question 56

arthropoda

Answer 56

bilateral symmetry 2 gut openings segmentation have exoskeletons made of chitin spider, crab, scorpion

Question 57

chordata

Answer 57

bilateral symmetry 2 gut openings segmentation Have a notochord to support the body and sophisticated digestive system Fish, dog, whale, zebra, human

Question 58

chordata

Answer 58

a large phylum of animals that includes the vertebrates together with tunicates (sea squirts) and lancelets. They are distinguished by the possession of a notochord at some stage during their development.

Question 59

five types of vertebrates

Answer 59

fish, amphibians, reptiles, birds and mammals

Question 60

mammalia

Answer 60

skin covered in hair or fur skin also has sweat glands habitat on land and in water warm-blooded breathing through lungs

Question 61

aves

Answer 61

skin covered in feathers, which are waterproof and insulate the body habitat on land most species can fly and some can also swim warm-blooded and lay eggs breathing through lungs

Question 62

reptilia

Answer 62

skin is dry and has scales habitat on land cold-blooded and most species lay eggs breathing through lungs homodont are sharp and cone-shaped

Question 63

amphibia

Answer 63

skin is exposed and moist habitat on land and in water cold-blooded and lay eggs no external ears

Question 64

fish

Answer 64

covered in slimy scales habitat in fresh or sea water, with fins and tails adapted to swimming and balancing cold-blooded and lay eggs breathing through gills

Question 65

clade

Answer 65

A group of organisms, both extant and extinct that share an ancestor.

Question 66

cladistics

Answer 66

A system of classifying organisms according to shared characteristics, based on ancestry.

Question 66

cladogram

Answer 66

A diagram that shows the evolutionary relationship of a group of organisms.

Question 67

molecular clock

Answer 67

a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged.

Question 68

what part of dna is best for analysis

Answer 68

non coding because they are highly repetitive sequences and mutations will occur more frequently in these sections of DNA

Question 69

node

Answer 69

a point on a cladogram where divergence occurs. Also called a branching point.

Question 70

analysis of cladograms

Answer 70

The branching pattern is assumed to represent the evolutionary relationship between species. If extinct species are included, information must be given on whether the cladogram is based on morphology only because DNA generally is not available for the analysis, although there are some exceptions to this. The more nodes there are between species, the more distant their relationship. Mutations at the DNA and protein level are assumed to occur at a constant rate. For example, 1 base change per 10 9 years – this may seem like a long time, but remember there are billions of bases in genomes. Some cladograms are drawn to scale, that is the length of the branches is proportional to the time since divergence.

Question 71

The root of a cladogram is

Answer 71

the point prior to any divergence where the organisms share certain characteristics.

Question 72

An outgroup is

Answer 72

the most distantly related organism on a cladogram. It will be on the longest branch of the tree and will be set apart from the other branches.

Question 73

Phylogenetic tree

Answer 73

a diagram that represents evolutionary relationships among organisms based on physical and genetic similarities and differences.

Question 74

The order Artiodactyl contains

Answer 74

mammals such as cows, sheep and camels. These are often commonly called hoofed mammals.

Question 75

figwort family ( Scrophulariaceae )

Answer 75

more than 275 genera with around 5 000 species, based on shared morphological features. The figwort family was the 8th largest of all of the angiosperm families.

Question 76

what happened when scientsists compared chloroplast dna

Answer 76

it became apparent that what was once thought to be one clade, i.e. all descendants from one ancestor, was actually five clades. Until this analysis, it was impossible to distinguish between the five clades, because their morphology was so similar due to convergent evolution. Now the figwort family has around 200 species and is the 36th largest family of all of the angiosperms. NOW: Calceolariaceae , Orobanchaceae , Scrophulariaceae , Stilbaceae and Veronicaceae .