Classification and Biodiversity Flashcards
(91 cards)
1
Q
what do biologists use a phylogenetic method to do?
A
to group organisms based on evolutionary history
2
Q
What do closely related organisms share?
A
-a more recent common ancestor and will be in the same groups
-they are also likely to share physical characteristics
3
Q
In this phylogenetic tree, what does moving up represent?
A
moving forward in time
4
Q
What are species at the top?
A
exist today
5
Q
What doe shorter branches indicate?
A
extinct species and points where branches join represent common ancestors.
6
Q
What is classification?
A
the placing of organisms into groups. Larger groups are divided up into progressively smaller groups, forming a hierarchy.
7
Q
What is hierarchy?
A
a system of ranking in which small groups are nested components of larger groups
8
Q
What is taxonomy?
A
The identification and naming of organisms.
9
Q
What is a taxon?
A
Each group within a classification system is called a taxon.
10
Q
What is the hierarchy of biological classification? (largest to smallest taxon)
A
-Domain
-Kingdom
-Phylum
-Class
-Order
-Family
-Genus
-Species
11
Q
What is the acrostic?
A
Did
King
Philip
Come
Over
For
Golden
Silver
12
Q
What happens as the groups to get smaller?
A
organisms become more closely related as groups get smaller= smaller groups nested within bigger groups/ no overlap
13
Q
What are taxa?
A
are discrete - at any level of classification, an organism belongs in one taxon and no other.
14
Q
What is the hierarchal classification of humans?
A
DOMAIN- Eukarya
KINGDOM- Animalia
PHYLUM- Chordates
CLASS- Mammalia
ORDER- Primates
FAMILY- Hominidae
GENUS- Homo
SPECIES- Sapiens
15
Q
What does classification help us to do?
A
infer evolutionary relationships, indicating that organisms in the same taxon are closely related e.g. discovering an animal with a beak and feathers allows us to predict other bird-like characteristics.
16
Q
What else does classification do?
A
also improves scientific communication by providing concise terms, like “bird” instead of “vertebrate egg-laying biped with a beak and feathers.”
17
Q
What are classification systems?
A
tentative and may change as scientific knowledge advances
18
Q
Use the velvet worm as an example to explain how classification of species can change:
A
Velvet worms have a soft body and paired jointed limbs
Therefore, have characteristics of moth Annelida (soft body) and Arthopoda.
So an new phylum, Onchophora, was defined
19
Q
What is a domain?
A
the largest taxon, encompassing all living things.
20
Q
What has recent biochemical evidence shown about the kingdom prokaryote?
A
should be split into two separate groups based on some fundamental biochemical differences
21
Q
What do all other organisms have?
A
eukaryotic cells
22
Q
What are domains?
A
a scheme of classification which suggests all organisms evolved along three distinct lineages, called domains
23
Q
What do organisms in each domain share?
A
a distinctive, unique pattern of ribosomal RNA, which establishes their close evolutionary relationship.
24
Q
What are the three domains? (two for prokaryotes, one for eukaryotes)
A
Bacteria (Eubacteria)
Archaea (Archaeabacteria)
Eukaryota
25
What is Bacteria (Eubacteria)?
the true bacteria such as E.coli and Salmonella
26
What is Archaea (archaebacteria)?
Extremophile prokaryotic cells living in diverse conditions, such as high temperature, pH, salinity, and pressure.
They are prokaryotes, don’t have a peptidoglycan cell wall
27
What are Eukaryota?
All eukaryotic cells, containing a membrane bound nucleus - includes plants, animals, fungi, protoctists
28
What are the five kingdoms?
-Prokaryota
-Protoctista
-Fungi
-Animalia
-Plantae
29
What are prokaryota and what are their features?
Microscopic organisms.
All bacteria and cyanobacteria (blue-green algae).
features:
No nucleus- DNA free in the cytoplasm
Peptidoglycan cell wall
70s ribosomes
Escherichia coli
Slime capsule, flagella, plasmid.
30
What are protoctista?
Mainly single celled. Lack tissue differentiation.
Examples include:
Plankton
Spirogyra
Amoeba
31
What are fungi?
-have cell walls made of chitin and can reproduce both asexually and sexually.
-Sexual reproduction produces spores, helping fungi adapt to changing environments.
-Examples include single-celled yeast and moulds like Penicillium and mushrooms, which have hyphae that form a mycelium (fungal body).
32
What are animalia?
multicellular organisms with nervous coordination and no cell walls.
There are 35 animal phyla, each with diverse body plans, such as Annelida, Arthropoda, and Chordata.
33
What are plantae?
Plants are multicellular organisms that photosynthesize and have cell walls made of cellulose.
Examples include mosses, ferns, conifers, and flowering plants (angiosperms).
34
What is a phylum?
is a sub-group of a kingdom
35
What do members of every phylum have and give examples?
A distinct body plan:
-Annelida are soft bodied and segmented
-Arthropoda have a chitinous exoskeleton and jointed limbs
-Chordata contains animals with vertebrates
36
What is a class?
A class is a sub-group of a phylum. For example, Mammalia is a class within the phylum Chordata, and Insecta is a class within Arthropoda.
37
What is an order?
An order For example, Lepidoptera (butterflies and moths) is an order within the class Insecta
38
What is a family?
a group within an order, such as the rose family Rosaceae.
39
What is a genus?
is a group of similar organisms, like the genus Panthera, which includes lions and tigers.
40
What is a species?
a group of phenotypically similar organisms that can interbreed to produce fertile offspring
41
Panthera leo (lion) and Panthera tigris (tiger) are different species and cannot produce fertile offspring.
If they were to mate and produce offspring, what must be true about their offspring?
42
Panthera leo (lion) and Panthera tigris (tiger) are different species and cannot produce fertile offspring.
If they were to mate and produce offspring, what must be true about their offspring?
infertile hybrid e.g. tiger or liger
43
What did Carl Liannaeus do?
To avoid confusion from, introduced the binomial system, giving each organism two names.
44
What does taxonomy involve and what does this allow us to do?
Taxonomy involves identifying and naming organisms, allowing us to:
•Discover and describe biological diversity
•Investigate evolutionary relationships
•Classify organisms based on these relationships
45
46
How to use the binomial naming system?
Each organism has two names: genus and species.
2.The genus name is capitalised and comes first.
3.The species name is lowercase and comes second.
4.Write the full name the first time (e.g., Panthera leo), then abbreviate (e.g., P. leo).
5.Always use italics (or underline the names if handwritten).
47
What three advantages does the bionomial system have?
•Unambiguous naming
•Latin-based - usable worldwide
•Indicates relatedness when species share part of their name (e.g., Panthera leo and Panthera tigris)
48
Turdus roelhi is a species of thrush that lives in Tanzania. Suggest how they became a separate species from Turdus merula.
•Geographical isolation – allopatric speciation.
•No flow of genes.
•Different selection/environmental pressures.
•Different random mutations.
•Gene pools become substantially different they can no longer interbreed and form fertile offspring.
49
What does the theory of evolution suggest?
-that widely separated groups of organisms share a common ancestor, leading to shared basic features.
-The more similar two organisms are, the more recently they diverged from a common ancestor.
50
What do homologous structures have?
-different functions but similar form and developmental origin, indicating a more recent common ancestor. -This is an example of divergent evolution, where a common ancestral structure evolves to perform various functions.
51
What is an example?
-the pentadactyl limb, a five-digit limb found in four classes of vertebrates (amphibians, reptiles, birds and mammals).
-It evolved to have a different function, such as running, swimming, flying, jumping.
52
What do analogous structures do?
perform the same function and have a similar shape but different developmental origins.
53
What may two animals be? (1)
look similar without being closely
related, having evolved to survive in similar environments without a recent common ancestor
54
What is this an example of? (2)
convergent evolution, where
structures have similar properties but different developmental origins.
55
Why must we ensure we spot analogous features?
so mistakes are not made when classifying organisms
56
Use the images below to explain why looking similar does not mean you are closely related:
-Both Chordates that have a streamline shape for swimming and live in a marine environment. -However a shark is a fish with fins made of cartilage whereas a dolphin is a mammal and has the pentadactyl limb made from bone.
57
What do biochemical methods, like DNA fingerprinting and enzyme studies do? (1)
assess the relatedness of organisms and reduce classification errors from convergent evolution.
58
What do these methods do?
measure the proportion of shared DNA or proteins between species to estimate relatedness- the more shared DNA or proteins (such as enzymes), the more closely related the organisms
59
What are DNA fragments/proteins separated by?
gel electrophoresis and displayed as bands, allowing scientists to compare their position and size to determine similarity
60
What conclusions could be drawn about how closely related species A, B and C are? Explain your answer. (image)
Species A shares a more recent common ancestor with species B as they have more similar bands from separation of their proteins. Species A and C have less similarities between their proteins and therefore bandings and so have a more distant common ancestor.
61
Why do biochemical methods reduce the mistakes made in classification due to convergent evolution?
Two organisms may have analogous structures, e.g. wings of a bat and an insect, they have the same function and so can appear to have a common origin.
-Biochemical methods can confirm if these organisms are indeed closely related or if the structures are derived from a different origin.
62
What is the definition of biodiversity?
The number of species and the number of individuals within each species in a specified region
63
What does the number of species and organisms largely depend on?
the environment:
High light intensity supports more plant growth, which in turn supports more herbivores and carnivores.
•Equatorial regions have much higher biodiversity than polar regions.
64
What are the three reasons biodiversity can change for?
Succession: Over time, species composition changes. Animal biodiversity increases, while plant biodiversity decreases.
Natural Selection: The gradual process by which inherited traits become more or less common in response to environmental changes.
Human Influence: Human activities have made many environments less hospitable, decreasing biodiversity and often leading to extinction.
65
Many animals and plants support human civilisation:
•A few plant species, like wheat and rice, provide staple foods worldwide.
•Medicinal drugs, such as those for heart disease and antibiotics, are derived from plants and animals.
•Living organisms supply raw materials like rubber and cotton.
66
Humans are the biggest threat to biodiversity. List three human activities that reduce biodiversity:
• habitat destruction through deforestation etc
• overhunting
• introduction of new species
67
what does decreasing biodiversity mean?
means losing potential new foods and useful traits, like disease resistance, for crops.
However, these arguments are selfish and human-centred.
68
What does a biodiversity index monitor?
monitors habitat biodiversity over time and compares different habitats.
69
What is Simpson’s Diversity Index allow us to do?
calculate the diversity of a habitat, such as invertebrates in a stream.
70
What does a higher value indicate?
Higher Biodiversity
71
What is the formula?
S(D)= 1- (sumof)(n-1)/N(N(N-1)
72
What do the things stand for in the formula?
S(D) = Simpson's diversity index
≥ = sum of
N = the total number of organisms present
n = the number in each species
73
This reading was taken in the open water of the stream. Another reading was taken at the bottom of the stream, which had a Simpson’s index of 0.84. (other one = 0.50)
What does this tell us about the biodiversity of the two habitats?
The community at the bottom of the stream is more biodiverse than in the open water of the stream.
At the bottom of the stream on the river bed, there are more habitats below and between stones, meaning there are more ecological niches supporting more species, increasing the biodiversity
74
How can biodiversity within a species be assessed genetically?
by examining the variety of alleles in a population’s gene pool, focusing on the proportion of polymorphic loci.
75
What is polymorphism?
refers to the presence of multiple forms or types within a species, resulting from polymorphic genes (multiple alleles for the same gene).
76
How can genetic biodiversity be measured?
•The number of alleles at a locus
e.g. T/t, IA/IB/IO.
•The proportion of the population
with a particular allele
77
what does the more alleles at a locus mean?
the greater the biodiversity and polymorphism
78
In this example, which gene shows the greater polymorphism? What does this say about its biodiversity?
•Gene T controls height with two alleles.
•Gene S controls pollen germination with 31 alleles.
Gene S shows greater polymorphism and therefore greater biodiversity
79
What does it mean in 98% of the alleles for a gene are the same recessive allele?
biodiversity for that gene is low.
80
If only 50% are recessive, then only 50% are other alleles- what does this mean?
the biodiversity for that gene is higher
81
How is biodiversity assessed at a molecular level?
As it is very difficult to count every single allele in a population, researchers collect DNA samples and analyse base sequences to find variations between individuals, using DNA fingerprinting and sequencing.
82
What does the greater the variation in the DNA base sequence mean?
the greater the genetic diversity of the population.
83
What happens when a species adapts to an environment?
useful traits become more common.
84
What are Anatomical Traits?
-Desert animals cope with extreme temperatures and limited water. Different organisms have unique adaptations to these challenges.
85
What are physiological traits?
Mammals and birds, being endothermic, use significant energy to maintain body temperature and must avoid wasting energy in the cold.
86
What are behavioural traits?
Desert animals like kangaroo rats and lizards live in burrows to avoid extreme temperatures and emerge at night to feed
87
What are mating rituals?
Animals use displays to increase mating chances. Examples are the peacock's tail or the flamingo dance.
88
Like many plants, hawthorns flower in spring when pollinating insects emerge. How could global warming affect this relationship?
Plants are flowering before their pollinating insects have emerged as the warmer temperatures lead them to believe it is earlier in the year.
89
What is divergent evolution?
When evolution from a common ancestral structure gives rise to structures that perform many different functions
90
What are phylogenetics?
The study of evolutionary history and relationships among organisms. Can be represented as a tree
91
What is a kingdom?
The second largest grouping, consisting of Prokaryota, Protoctista, Fungi, Animalia and Plantae
