Exam 3 Flashcards

1
Q

Taxonomy

A

science of classifying organisms into taxa with a traditional Linnaean system (after Carl Linnaeus) uses a nested hierarchical system

At each sublevel in the taxonomic classification system, organisms become more similar.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Binomial nomenclature

A

Species name = genus + species ‘epithet’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Biologists group organisms based on shared characteristics. What are the 6 traits?

A

Fossil records
Morphology
Physiology
Behavior
Embryological development
DNA/RNA sequences

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Phylogenetic systematics

A

Reconstruction and study of evolutionary relationships

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Phylogeny

A

Hypothesis about relationships among taxa
Depicted as a phylogenetic tree or cladogram
A branching diagram depicting evolutionary relationships

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Taxon (taxa, pl)

A

group(s) of organisms (species, family, domain, etc.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Clade

A

any branch or lineage (lines in cladogram)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Branch point (node)

A

splitting represents single lineage evolving into two clades

Nodes are most recent common ancestor (MRCA) of subsequent clades

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Limitations of cladograms

A

Often, closely related taxa look similar, but not always

If evolved under different circumstances (selection pressures), the taxa may look very different despite their close relation

Unless specified, the length of the clade does not indicate amount of time passed since divergence (node)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Two Options for Similarities

A

Homologous characters
Analogous characters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Analogous characters

A

Similar due to functional or ecological constraints/pressures
Characters can be very similar in appearance due to convergent evolution
Convergence occurs in unrelated (or distantly-related) taxa when characters are shaped by similar ecological or evolutionary constraints (selection pressures)
May be referred to as ‘homoplasy’ (instead of homology)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Homologous characters

A

Similar due to divergent evolution (same ancestral source)
Based on genetics and developmental origin
The deeper the similarity, the more likely it’s of same origin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Monophyletic groups (monophyly)

A

the most recent common ancestor and all descendants
According to cladistic analysis, only monophyletic groups should be named and recognized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Building Phylogenetic Trees

A

All organisms within a clade share an exclusive point (node) on the tree.

A clade may contain multiple groups, as in the case of animals, fungi and plants, or a single group, as in the case of flagellates.

Groups that diverge at a different branch point, or that do not include all groups in a single branch point, are not considered true clades.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Ancestral character state (aka plesiomorphy)

A

The character state present in a lineage immediately before a character state change

Found in common ancestor of taxa, but not all displayed taxa have it
Basal clade taxon is expected to display most ancestral character states

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Shared derived character state (aka synapomorphy)

A

Arose (derived) within the larger clade
Distinguishes taxa that share it from those that do not
Provides information about relatedness within the larger group
Used to identify branch points (nodes) within the larger clade

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Rule of parsimony

A

Prefer the simplest cladogram with the fewest steps or events

18
Q

Two patterns of evolution that may be misleading

A

Convergent evolution
Evolutionary reversal

19
Q

Convergent evolution

A

Structures evolving from same evolutionary pressures but not from a common ancestral trait
Example: wings in birds and wings in insects
Example: leglessness in (some) lizards and leglessness in snakes

20
Q

Evolutionary reversal

A

Ancestral traits are sometimes lost in descendants in one group
Example: loss of limbs in snakes (most other squamates have legs)
Example: loss of hindlimbs in cetaceans

21
Q

6 reasons why do phylogenies matter?

A
  1. Understanding of evolutionary processes
  2. Research on related species may help to better understand human health, medical issues
  3. Track evolution of parasites and viruses
  4. Use biotechnology to produce more productive crops, domesticated animals
  5. Produce more effective drugs (e.g. human insulin)
  6. Improve conservation efforts for threatened and endangered species
22
Q

Organismal Ecology

A

Study of adaptations that enable individuals to live in specific habitats. These adaptations can be morphological, physiological, and behavioral.

23
Q

Population Ecology

A

Study of demography and intraspecific interactions; includes the number of individuals in an area and how and why population size changes.

24
Q

Community Ecology

A

Study of interspecific interactions at small and large scales (e.g., symbiosis and succession, respectively

25
Q

Ecosystem Ecology

A

Study of the storage and movement of nutrients and energy among organisms and the surrounding atmosphere, soil, and water.

26
Q

Landscape Ecology

A

Study of biomes and the conditions that influence their dispersion.

27
Q

Biogeography

A

the study of the geographic distribution of living things and the abiotic factors that affect their distribution.

28
Q

endemic species

A

one which is naturally found only in a specific geographic area that is usually restricted in size.

29
Q

cosmopolitan species

A

species which live in a wide variety of geographic areas.

30
Q

Abiotic Factors affecting distribution

A

Energy Sources
Sunlight
Ocean Upwelling
Temperature
Presence, Type, and Changes in Water
Freshwater
Saltwater
Frozen water
Seasonal water changes
Nutrients and Inorganic Materials
Other factors:
Aquatic: Oxygen, salinity, currents, tides, vents
Terrestrial: Fire, wind
Both: Volcanism, tectonics, natural events

31
Q

Ocean upwelling

A

an important process that recycles nutrients and energy in the ocean. As wind pushes offshore, it causes water from the ocean bottom to move to the surface, bringing up nutrients from the ocean depths.

32
Q

Fire impact

A

mature cones of the jack pine (Pinus banksiana) open only when exposed to high temperatures, such as during a forest fire. A fire is likely to kill most vegetation, so a seedling that germinates after a fire is more likely to receive ample sunlight than one that germinates under normal conditions

33
Q

Using your understanding of ocean upwelling, explain one reason why marine life is more abundant near some coastlines than others.

A
34
Q

Draw and label a cladogram depicting the relationships of four taxa (A, B, C, and D). Taxon A occupies the basal clade. Taxa B and C are sister taxa. Indicate the occurrence of a homologous characteristic shared by all taxa (refer to it as ‘cells’). Then indicate the occurrence of an analogous characteristic shared by taxa C and D (refer to it as ‘aerobic’).

A
35
Q

Use the cladogram below to complete the following:
What named group is monophyletic?
What ancestor is shared by all displayed taxa?
What shared derived character is diagnostic of bilateria?

A

bilateral symmetry

ancestor 1

having bilaterial symmetry

36
Q

Climate

A

long-term, predictable atmospheric conditions of a specific area

37
Q

Weather

A

conditions of the atmosphere during a short period of time

A specific weather event occurring in a particular region is not evidence of global climate change

38
Q

Different biomes

A

Tropical forest
Desert
Tundra
Temperate forest
Boreal forest – taiga
Temperate grassland
Savanna (grasses)
Chapparal – scrub forest

39
Q

Aquatic zones in water

A

Neritic zone (shallow coastline)
Intertidal Zone
Photic Zone
Aphotic zone
Abyssal zone
Benthic realm

40
Q

If you were to travel up Mount Kilimanjaro in Tanzania, you would pass through several habitats: savanna at the base, forest on the slopes, and tundra near the top. Explain how such diverse habitats can be found at one location near the equator.

A