Classification and evolution Flashcards
(82 cards)
1
Q
Define biological classification
A
The organisation of living and extinct organisms into systematic groups based on similarities and differences between species.
2
Q
A
3
Q
Why are organism classified
A
1) Convenience
2) Identify species
3) Predict characteristics
4) Find evolutionary links
4
Q
Define taxonomy
A
The study and practice of naming and classifying species and groups of species
within the hierarchal classification scheme.
5
Q
What is the order of the hierarchical classification
A
(Do ,Keep, Pond, Clean, Or, Frogs, Get, Sick)
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
6
Q
A
7
Q
Why was it a problem naming organism based on particular characteristics (common names)
A
1) The same organism may have a completely different common name in different parts of one country.
2) Different common names are used in different countries.
3) Translation of languages/dialects may give different names.
4) Same common name could be used for a different species in another part of the world.
8
Q
Explain how was the problem of naming organism based on particular characteristics (common names) solved
A
Linnaeus used Latin naming as a method of providing a universal language. This means every scientist will use the same name for a particular species, avoiding the confusion associated with using common names.
9
Q
Define the binomial system
A
A system of naming species in which each species has two names: a generic name and a specific description.
10
Q
Explain the rules of binomial naming
A
On text:
Generic name begins with capital letter and species name begin with a lowercase
The names are given in italics (bold)
** Canis familiaris **
On paper:
Generic name begins with capital letter and species name begin with a lowercase
The names must be underlined
11
Q
A
12
Q
Explain why the binomial system is used
A
No two species would ever have the same genus and species name. Two different species could have the same species name, but their genus would be different.
13
Q
What are the five kingdoms
A
Prokaryotae
Protocista
Animalia
Fungi
Plantae
14
Q
Explain evidence for the classification for the five kingdoms
A
1) Early classification relied on observable features only to place organisms into groups such as appearance and anatomy.
2) Aristotle classified all living things as either plant or animal. Then after animal if they Live & move in water or Live & move on land or Move through the air
2) microscopes were developed over time and more organisms could be studied in detail, it started to lead to changes in the classification groupings used. This led to the five kingdom system that was still based on observable
features, but also included observations made under the microscope.
15
Q
Explain the general features of prokaryotae
A
unicellular
no nucleus or other membrane-bound organelles - a ring of ‘naked’. DNA - small ribosomes
no visible feeding mechanism - nutrients are absorbed through the cell wall or produced internally by photosynthesis.
16
Q
What are examples of prokaryoate
A
Examples include the bacteria Escherichia coli,Staphylococcus aureus, and Bacillus anthracis.
17
Q
Expain the general features of protocista
A
(mainly) unicellular
a nucleus and other membrane-bound organelles
some have chloroplasts
18
Q
What are examples of protocista
A
Examples include species belonging to the genera Paramecium and Amoeba.
19
Q
Expain the general features of fungi
A
unicellular or multicellular
a nucleus and other membrane-bound organelles and a cell wall mainly composed of chitin
no chloroplasts or chlorophyll
no mechanisms for locomotion
most have a body or mycelium made of threads or hyphae
nutrients are acquired by absorption - mainly from decaying material - they are saprophytic feeders - some are parasitic
most store their food as glycogen.
20
Q
What are examples of fungi
A
Examples include mushrooms, moulds, and yeast
21
Q
Expain the general features of plantae
A
multicellular
a nucleus and other membrane-bound organelles including chloroplasts, and a cell wall mainly composed of cellulose
all contain chlorophyll
most do not move, although gametes of some plants move using cilia or flagella
nutrients are acquired by photosynthesis - they are autotrophic feeders - organisms that make their own food
store food as starch.
22
Q
What are examples of plantae
A
Examples include flowering plants such as roses, trees such as oak, and grasses.
23
Q
Expain the general features of animalia
A
• multicellular
a nucleus and other membrane-bound organelles (no cell walls)
no chloroplasts
move with the aid of cilia, flagella, or contractile proteins, sometimes in the form of muscular organs
nutrients are acquired by ingestion - they are heterotrophic feeders
food stored as glycogen.
24
Q
What are some examples of animalia
A
Examples include mammals such as cats, reptiles such as lizards, birds, insects, molluses, worms, sponges, and anemones.
25
Explain evidence for the classification for the three domains
1) Scientists started to discover more about molecular biology, biochemistry and cell structure in the end of the twentieth century.
2) This led to the discovery that there were some major differences within the prokaryotae kingdom that suggested they had evolved
independently and weren’t closely related.
3) Carl Woese suggested a new classification system in 1990, based on studies of the ribosomal RNA gene. He divided the prokaryotae kingdom into two kingdoms; eubacteria and archaebacteria.
4) Three domains: Bacteria, archaea and eukarya.
26
What are the three domains
Three domains: Bacteria, archaea and eukarya.
27
Explain how evidence of studying biological molecule can help to determine how much more closely related species are compared to observing features
1) Certain biological molecules are found in all living things for the purposes of respiration and protein synthesis etc.
2) We can assume that the earliest forms of life would have had identical versions of these biological molecules. This means that any changes we see would be due to evolution. So two organisms with the same version would be more closely related.
3) You can compare things like how DNA is stored and the sequence of DNA bases to help determine how closely related species are.
4) You can also compare the sequence of amino acids in proteins from different
organisms.
28
Describe the domain bacteria
Bacteria:
1. Cell wall made of peptidoglycan, simpler plasma membrane structure
2. Flagella with a different internal structure (no 9+2)
3. Different enzymes (RNA polymerase for synthesising RNA).
4. No proteins bound to their genetic material.
5. Different mechanisms for DNA replication and for synthesising RNA.
29
Describe the domain archea
Archaea:
1. Similar enzymes (RNA polymerase) for synthesising RNA.
2. Similar mechanisms for DNA replication and synthesising RNA.
3. Production of some proteins that bind to their DNA.
4. Different cell wall and plasma membrane structure
30
Describe the domain eukarya
Contain Four kingdoms ( Protoctista, Fungi, Plantae , Animalia)
Archae is more closely related to Eukarya than to bacteria
31
Why is essential to sue molecules such as DNA or cytochrome C for evidence to be used in classification
These molecules offer a universal and detailed way to compare organisms. This means that similarities and differences can be identified in these molecules which can be used to compare species.
32
Explain why molecules such as starch or the enzyme amylase are not used for classiifaiaton
These molecules are not universal therfore cannot be used to compare organisms thus cannot be used to show evolutionary relationship
33
Explains artificial classification
• Done for convenience e.g. yellow flowers and blue flowers.
• Is only based on a few characteristics.
• Does not reflect evolutionary relationships.
• Provides limited information.
• Is stable.
34
Explain natural classification
• Involves a more detailed study of individuals in a species.
• Uses many characteristics.
• Reflects evolutionary relationships.
• Based on homology.
• Provides a lot of useful information.
• May change with advancing knowledge.
35
Define homology
The existence of shared features that are inherited from a common ancestor. The shared features may not be used for the same function.
36
Define phylogeny
The study of evolutionary relationships between organisms.
37
What are used to represent evolutionary relationships between organisms
phylogenetic trees
38
Explain the advantages of phylogeny
1) It can be done without referring to the Linnaean classification. E.g. a dolphin has many characteristics in common with fish and so may be classified as a fish. However, an understanding of the evolutionary relationships and phylogeny of the dolphin confirms its classification as a mammal not a fish.
2) It produces a continuous tree whereas
classification requires discrete taxonomical groups.
3) It is not as misleading as the hierarchal classification of the Linnaean system which does not illustrate the time between divergence or show how long the species has existed for. It implies that all the different groups within the same rank are equivalent, when in fact one may be much older than another. It also does not illustrate the levels of diversity or degree of biological differentiation.
39
Define phylogenetic species concepts
The concept of a species as an irreducible group whose members are descended from a common ancestor and who all possess a combination of certain defining, or derived traits.
40
Explain the phylogenetic species concepts
1) Biological species concept: the ability of two individuals to successfully produce viable, fertile offspring.
2) Morphological species concept: whether individuals look similar.
3) Phylogenetic species concept: how closely related individuals are evolutionarily.
4) Ecological species concept: whether the individual use or can use the same
set of biological resources; in other words, whether they occupy the same “niche”.
41
Explain how to interpret a phylogenetic tree
The node is a region where all species are a common ancestor of
When two branches connect that is the point of the most recent common ancestor of the two species .
If a branch doesn’t reach the end of the timeline it is extinct.
42
Explain Darwin’s proposal for the mechanism of natural selection for the theory of evolution
1) Darwin's ideas were developed during the observations he made on his travels around the world to places such as the Galapagos Islands.
Darwin made four main observations:
a) Offspring generally appear similar to their parents.
b) No two individuals were identical.
c) Organisms have the ability to produce large numbers of offspring.
d) Populations in nature tend to remain fairly stable in size.
Darwin realised that variation was important in understanding the evolution of species and realised that there is a struggle for survival with those better-adapted individuals surviving and reproducing more.
43
Explain Lyell’s contribution for mechanism of natural selection for the theory of evolution
1) In 1831, aboard the HMS Beagle, Darwin read the book 'Principles of Geology, written by his friend Charles Lyell.
2) He suggested fossils were evidence of animals that had lived millions of years ago. We now have evidence that supports this.
Lyell also popularised the principle of uniformitarianism.
This is the idea that the Earth was shaped by forces that you can still see in action today (sedimentation in rivers, volcanic activity, wind erosion, etc). This challenged other geologists who tried to explain geological formations as a result of biblical events, e.g. floods.
Lyell's work allowed Darwin to think about evolution as a slow process, where small changes gradually accumulate over a very long tie
44
Explain Wallace’s contribution for mechanism of natural selection for the theory of evolution
1) Wallace developed his theory of natural selection independently of Darwin.
2) Wallace collected much evidence and made many observations in parts of the world such as the Amazon and South East Asia.
Wallace’s observations included:
a)Some organisms had advantageous adaptations evolved by natural selection.
B) Geographical boundaries often marked species boundaries.
C) Most of the individuals found in a habitat were the best fitted for that environment.
Wallace and Darwin later collaborated on joint papers on the subject of evolution
by natural selection in 1858. This was followed a year later by Charles Darwin’s book known as ‘The Origin of Species’.
45
What are the types of evidence that can be used to support the theory of evolution by natural selection
1) Fossil evidence (palaeontology)
2) Comparative anatomy
3) Comparative biochemistry
46
Define fossils
The mineralised or preserved remains of
an animal, plant or microorganism. Fossils may also consist of other traces of organisms, such as footprints, burrows and faeces (coprolites).
47
Describe the process of fossil formation
Animal or plant dies.
Organism becomes buried under sediment.
High temperature and pressure turns the sediment into stone.
The remains dissolve and leave behind a space.
Minerals crystallize in the space and forms a cast (fossil).
48
Explain fossil evidence for evolution
1) Fossils of the simplest organisms (e.g. bacteria and algae) are found in the oldest rocks, while fossils of more complex organisms are found in more recent rock layers. This supports the evolutionary theory that simple life forms gradually evolved over an extremely long time period into more complex organisms.
2) The sequence in which the organisms are found matches their ecological links to each other. For example, plants came before animals on Earth.
3) By studying similarities in the anatomy of fossil organisms, scientists can show how closely related organisms have evolved from the same ancestor.
4) Fossils allow relationships between extinct and living organisms to be investigated.
49
Define homologous structure
A structure that appears superficially different (and may perform different functions) in different organisms, but has the same underlying structure.
50
Why might organisms from different taxonomic group show similar anatomical features
Organisms may have similar anatomical features. However, the functional it is used for is different. This would suggest they have all evolved from a common ancestor, as the vertebrate limbs have all evolved from the same structure.
This provides evidence for divergent evolution and would most likely be due to migration or loss of habitat. Therefore, they belong to different taxonomic groups as they are not the same species.
51
Explain comparative biochemistry
1) This is the study of similarities and differences in the proteins and other
molecules that control life processes.
2) Some important molecules are highly conserved (remain almost unchanged) among species.
3) Slight changes that occur in these molecules can help identify any evolutionary links.
a) There are many possible different types of amino acids, but only 20 are used to make proteins – they are the same in all organisms.
b) The molecule of inheritance in all cellular organisms is DNA.
C) The genetic code that specifies an organism’s amino acids is basically the same in all organisms.
d) ATP is the universal currency for energy in the cells of all organisms.
52
What is comparative embryology
We can look at the similarities in the early stages of an organisms development.
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54
Define embryology
Embryology is the study of embryos – another source of evidence to show evolutionary evidence.
55
Explain molecular evidence
1) Differences in the sequence of a DNA molecule would be due to mutations as the genetic code is universal and so a particular sequence of DNA codes for the same sequence of amino acids in both an animal, plant or bacterium.
2) The more similar the sequence in part of the DNA, then the more closely related the species.
3) The more differences in the sequence in part of the DNA, then the earlier the evolution of the two species and so the less closely related they are.
56
Define variation
The differences between species and the differences within species.
57
Define interspecific variation
Differences between species.
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59
Define intraspecific variation
Variation between members of the same species
60
Explain intraspecific variation
a) This variation is used to study natural selection and evolution.
B) Phenotypic variation between individuals are often more difficult to detect.
C) Selective breeding often results in variation not often visible in wild populations, e.g. albinism (as it would be a disadvantage to survival for many).
61
Explain interspecific variation
It is used in order to identify different species and classify them
62
Define continuous variation
Variation in a feature that shows a range of phenotypes between two extremes with many intermediates, e.g. leaf length, body mass, height.
63
Explain continuous variation
a) Can also be known as quantitative variation.
b) Any feature that can be measured, for example, with a ruler or balance.
c) There are no distinct categories.
d) Characteristics are not controlled by a single
gene, but by a number of genes known as
polygenes. These features are known as
polygenic. For example, height. Describe the different types of variation.
64
Define discontinuous variation
Variation in a feature that has discrete categories without any intermediates, e.g. human blood groups.
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Explain discontinuous variation
a) Can also be known as qualitative or discrete variation.
b) There are distinct categories.
c) Characteristics are usually controlled by a single gene and the environment usually has no effect on the expression of the genes in the phenotype.
d) This can be presented as a bar chart or pie chart.
66
What are the different causes of variation
Genetic variation or environmental variation
67
Explained genetic variation
Genetic variation is due to the genes and alleles an individual possesses and there are different causes of genetic variation:
1) Alleles– genes have different versions (alleles) and the individuals in a species population may inherit different alleles of a gene.
2) Mutations– changes to the DNA sequence and therefore genes can lead to changes in the protein coded for and this can affect the physical and metabolic characteristics.
3) Meiosis– formation of gametes and the process of independent assortment and crossing over to ‘mix up’ the genetic material.
4) Sexual reproduction
5) Chance– random fertilisation as a result of which gametes combine.
68
Explain environmental variations
➢ Environmental variation can be due to climate, food, lifestyle etc.
➢ Characteristics controlled by environmental factors can change over an organism’s life.
69
Explain how factors of an organism can be influenced by genetic and environmental variation
a) E.g. In past century, humans have become taller due to better diet. However, you height is also limited to that of your genes.
b) Not all genes are active at any one time. For example, puberty.
C) Changes in the environment can also directly affect which genes are active.
70
Define adaptations
The way a structure, a function or an aspect of behaviour helps an organism to survive in its environment or perform an activity, such as feeding or evading predators.
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What are the different types of adaptations
1) Behavioural
2) Physiological
3) Anatomical
72
Explain behavioral adaptations
a) These are the ways that an organism acts to increase its chances of survival.
B) Behavioural adaptations can be inherited or learnt from their parents.
Survival behaviours: for example, possum ‘playing dead’ and rabbits freeze when a predator is nearby.
Courtship behaviours: many animals exhibit elaborate courtship behaviours to attract a
mate. For example, scorpions perform a dance to attract a partner.
Seasonal behaviours: these adaptations enable organisms to cope with changes in their environment e.g. migration and hibernation.
73
Explain physiological adaptations
These are the processes inside an organism’s body that increase its chances of survival.
Poison production: many reptiles produce venom to kill their prey and many plants produce poisons in their leaves to protect themselves from being eaten.
Antibiotic production:
some bacteria produce antibiotics to kill other
bacteria in their surroundings. (Streptomyces)
Water holding:
the water- holding frog (Cyclorana platycephala) can store water in its body. This allows it to survive in the desert for more than a year without access to water.
74
Explain anatomical adaptations
These are the structural features of an organism’s body that increase its chances of survival:
Body covering – e.g. hair, scales, spines, feathers and shells.
Camouflage- outer colour allows the organism to blend into its surroundings.
Teeth- shape and type of teeth are related to diet.
Mimicry- copying another animal's appearance or sound allows harmless organisms to fool a predator into thinking it is dangerous.
75
Explain convergent evolution
1) Different parts of the world provide very similar niches. This means organisms from
different taxonomic groups may have similar features even though they are not closely
related e.g. sharks and whales.
2) For example, the tail fins of a whale and fish perform the same role, but their structures
are actually very different. These are known as analogous structures.
76
Define convergent evolution
Convergent evolution: Organisms evolve similarities because the organisms adapt to similar environments or other selection pressures.
77
Define analogous structures
Analogous structures:
Structures that have adapted to perform the same function but have a different origin.
78
Compare the five kingdoms classification systems and the three domain system
Originally, the organisms were group based on shared and observable characteristics. However, with advances in science, unobservable similarities such as DNA and evolutionary relationships affect how organisms are classified,
Domains are a higher level of classification than Kingdoms and classify organisms based on the size of their ribosomes and types of RNA.
79
Whats is an example for continuous variation in plants, animals and microorganism
Plants:
Length of leaves
Animals:
Length of wingspan
Microorganism:
Length of microorganism
80
Whats is an example for dsicontinuous variation in plants, animals and microorganism
Plants:
Flower colour
Animal:
Blood type
Microorganism:
Antibiotic resistances
81
How can natural selection affect the characteristics of a population over time ho
Individuals in a population will have different alleles due to mutations in their gene or genetic variation through meiossi.
Selection pressure will occur where environmental factors pressures organism to compete.
The individuals with the advantageous alleles survive and reproduce. This passes on the advantageous allele to their offspring..
Over several generations the frequency of he advantageous alleles increases in the population as they become more adapted to the environment.
82
Explain how evolution in some species have resulted in implication for the human population
Pesticides resistance in insects:
• Some insects carry mutations that give them resistance to a pesticide.
• When pesticides are used, susceptible insects die, but resistant ones survive and reproduce.
• Over generations, the resistant allele becomes more common in the population.
• Implications for humans:
• Farmers must use stronger or different pesticides, which are more expensive and may have environmental consequences.
• Resistance can lead to reduced crop yields, affecting food supply and economics.
Antibiotic Resistance in Microorganisms (e.g. Bacteria) ;
• Some bacteria develop resistance mutations to antibiotics (e.g. MRSA).
• When antibiotics are used, non-resistant bacteria die, and resistant ones survive.
• Resistant strains multiply and spread, sometimes becoming untreatable with standard antibiotics.
• Implications for humans:
• Infections become harder to treat, leading to longer hospital stays, higher mortality, and increased healthcare costs.
• Greater urgency for developing new antibiotics, which is costly and time-consuming.
