Unit 2.1 All organisms are related through their evolutionary history

Question 1

phylogenetic classification?

Answer 1

evolutionary relatedness - if they are closely related - they may show physical similarities

Question 2

phylogenetic tree?

Answer 2

Branch points represent common ancestors of the organisms in the branches above. Living organisms are shown at the tips of branches.
Ancestral species (now extinct) would be shown in the trunk.

Question 3

Taxa?

Answer 3

levels of classification

Question 4

what do larger taxa contain?

Answer 4

smaller taxonomic groups

Question 5

what is the largest taxonomic groups called?

Answer 5

domains

Question 6

what is the smallest taxonomic group called?

Answer 6

species

Question 7

what are taxa?

Answer 7

discrete

Question 8

what is a phylogenetic classification system do?

Answer 8

allows us to infer evolutionary relationships.
If two organisms are so similar that we put them in the same taxon, we infer that
they are closely related.

Question 9

what is a domain?

Answer 9

largest taxon and all living thing belong to one of three Domains. Domains
were originally defined on the basis of rRNA base sequences.

Question 10

Eubacteria?

Answer 10

These are familiar bacteria such as E. coli and Salmonella.
They are prokaryotes.

Question 11

Archaea?

Answer 11

These are bacteria, and often have unusual metabolism;
for example some generate methane. They live in marginal
habitats and are also prokaryotes.

Question 12

Eukaryota?

Answer 12

This domain includes Plantae, Animalia, Fungi and
Protoctista. They are all eukaryotic organisms.

Question 12

what are the 5 main kingdoms?

Answer 12

Prokaryota , Protoctista, Fungi,Planta and animalia

Question 13

Prokaryota?

Answer 13

includes all bacteria and cyanobacteria. Microscopic, single celled,
organisms with no membrane bound organelles The cell wall is
made out of peptidoglycan or murein

Question 13

Prokaryota?

Answer 13

includes all bacteria and cyanobacteria. Microscopic, single celled,
organisms with no membrane bound organelles The cell wall is
made out of peptidoglycan or murein

Question 14

Protoctista?

Answer 14

eukaryotic organisms. Single celled. no tissue differentiation

Question 15

fungi?

Answer 15

Heterophobic eukaroytes with cell made up of chitin. reproduce by spores

Question 16

Planta?

Answer 16

Multicellular eukaryotes. Photosynthetic. cellulose cell walls

Question 17

Animalia

Answer 17

Multi cellular eukaryotes. Heterophobic. No cellulose cell walls. nervous coordination

Question 18

what do pentadactyl limbs do?

Answer 18

they show homologous features which suggest a common ancestor. Limbs are an example of divergent evolution where a common ancestral structure has evolved to perform ancestral structure

Question 19

what are the methods for relatedness?

Answer 19

DNA base sequence, DNA hybridisation, Amino acid sequence

Question 20

DNA base sequence?

Answer 20

During the course of evolution, species undergo changes
in their DNA base sequences, which accumulate until the
organisms are so different that they are considered to be a
different species. More closely related species show more
similarity in their DNA base sequence than those more
distantly related. DNA analysis has confirmed evolutionary
relationships, and corrected mistakes made in classification
based on physical characteristics.

Question 21

DNA hybridisation?

Answer 21

This involves comparing the DNA base sequence of two
species. To work out how closely related two species
of primates are, e.g. humans and the chimpanzee Pan
troglodytes, DNA from both is extracted, separated and cut
into fragments. The fragments from the two species are
mixed and, where they have complimentary base sequences,
they hybridise together. This has shown that chimpanzees and
humans have at least 95% of their DNA in common. Recent
studies have also shown that the hippopotamus and whale are
closely related.

Question 22

Amino acid sequence?

Answer 22

The sequence of amino acids in protein is determined by the
DNA base sequence. The degree of similarity in the amino acid
sequence of the same protein in two species will reflect how
closely related they are. Part of the fibrinogen molecule of
various mammal species has been compared and differences
in the amino acid sequences have allowed scientists to
propose an evolutionary tree for mammals.

Question 23

Immunology?

Answer 23

The proteins of different species can be compared using
immunological techniques. If you mix the antigens of one
species, such as the blood protein albumin, with specific
antibodies of another, the antigens and antibodies form
a precipitate. The closer the evolutionary relationship,
the more the antigen and antibody react and make more
precipitate.

Question 24

The sequence of amino acids ?

Answer 24

haemoglobin molecules of three species has been used
to determine their evolutionary relationships. The results show the same sections of the
haemoglobin molecules of three mammals. Each letter represents a different amino acid.

Question 25

what are the 2 definitions of the term species?

Answer 25

The morphological definition
The reproductive definition

Question 26

Morphological def?

Answer 26

if two organisms look very similar they are likely to
be the same species. There may be differences, such as the presence of a mane on
male lions but not females.

Question 27

The reproductive definition?

Answer 27

another way of defining species states that two
organisms are in the same species if they can interbreed to produce fertile
offspring. Dissimilar organisms may have a different number of chromosomes or
incompatible physiology or biochemistry, so a hybrid would not be viable.

Question 28

Sterile hybrids?

Answer 28

Closely related organisms may be able to interbreed, but will not produce
fertile offspring. A common example is the mule; the mule is a sterile hybrid of a male
horse and a female donkey.

Question 29

Taxonomy def?

Answer 29

identification and naming of organisms. This area of study allows us to:
Discover and describe biological diversity. Investigate evolutionary relationships between organisms.
Classify organisms to reflect their evolutionary relationships.

Question 30

What are the rules?

Answer 30

The genus name is the first word and
always has a capital letter.
The species name always comes
second and starts with a lower case
letter (small).
The first time a scientific name is
used in a text it should be written
out in full e.g. Panthera tigris; the
genus name can then be abbreviated
e.g. P.tigris.
Both names should be written in
italics or underlined when hand
written.

Question 31

what is biodiversity?

Answer 31

refers to two aspects of organisms in a given environment:
The number of species; sometimes called species richness.
The number of organisms within each species.

Question 32

what does the number of species and the number of organisms depend on?

Answer 32

the environment

Question 33

Succession?

Answer 33

Over time a community of organisms changes its habitat,
making it more suitable for other species. The change in the
composition of a community over time is called succession. It
increases animal biodiversity, but ultimately decreases plant
biodiversity.

Question 34

Natural selection?

Answer 34

Natural selection can generate and change biodiversity.

Question 35

Human influence?

Answer 35

Human activity has made the environment less hospitable to
living organisms. It has decreased biodiversity and in many
cases led to extinction.

Question 36

extinction?

Answer 36

loss of species

Question 37

what can extinction be caused by?

Answer 37

caused by a change in climate or habitat, increased competition,
new predators and new diseases.

Question 38

what type of process is extinction?

Answer 38

natural process

Question 39

what is the single greatest threat to biodiversity?

Answer 39

human destruction

Question 40

what is conservation?

Answer 40

actively planning to protect a species or habitat

Question 41

What are the types of conservation?

Answer 41

CITES,SSSI,Government agencies and other organisation,captive breedng programmes,seed banks and government legisation

Question 42

CITES?

Answer 42

Ban the sale of endangered species and their parts or
products.

Question 43

(SSSI) ?

Answer 43

Protect habitats from over-development.

Question 44

Government agencies
and other
organisations

Answer 44

Educate, lobby governments, raise awareness and fund
conservation projects. They also monitor changes in
biodiversity and alert us to changes in an organism’s risk
status.

Question 45

Captive breeding programmes?

Answer 45

Breed endangered species in captivity, ensuring limited human
contact. Then reintroduce the organisms into the wild and
monitor their numbers.

Question 46

Seed banks?

Answer 46

Carry out research into plant species and their genetic
diversity. Collect and preserve seeds of all species.

Question 47

Government legisation

Answer 47

Pass legislation to protect habitats and species at risk.

Question 48

How do plants and animals support human civilsation?

Answer 48

A potential source of food; a small number of plant species provide staple foods
for humans worldwide e.g. wheat and rice.
Essential raw materials such as cotton, rubber and wood.
Useful chemicals and pharmaceuticals, e.g. antibiotics, aspirin and many drugs
used to treat heart disease.
Disease resistant genes which can be spliced into new genomes to produce useful
GM crops.

Question 49

what does simpsons index do?

Answer 49

describes the biodiversity of motile
organisms, such as the invertebrates in a stream. The commonest way of calculating it
gives a numerical value and the higher the value, the higher the biodiversity.

Question 50

what is the formula?

Answer 50

S = 1 - ∑n(n-1)
N(N-1)