Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biodiversity > Midterm 1 > Flashcards

Midterm 1 Flashcards

(64 cards)

Start Studying
0
Q

How to measure biodiversity- molecular measures

A

Adv- DNA and RNA found in all living organisms, direct basis of comparison

Disadv- very incomplete, ignores phenotype

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

How to measure biodiversity- counting species

A

Adv- intuitive measure, relatively easy to quantify

Disadv- numbers don’t tell you about components/ what it’s made of, species identification can be hard

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

How to measure biodiversity- phylogenetic measures

A

Adv- incorporates historical info

Disadv- we don’t know the evolutionary relationships of most species yet

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

How to measure biodiversity- functional measures

A

Adv - captures ecological aspect of biodiversity,

Disadv- can be hard to measure, not clear how to compare between diff groups

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

Differences between land and seA

A

15% of described species live in the ocean

32 out of 33 phyla live in the ocean
12 out of 33 phyla live on land

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

Two types of characters

A

Primitive = plesiomorphic

Derived = apomorphic

A character may rn primitive at one level and derived at another

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

Monophyletic group

A

Group containing all descendants of a MRCA

AB
ABC
ABCD

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

Paraphyletic group

A

A group in which some but not all descendants of a single MRCA is present

CD

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

Poly phyletic group

A

A group that contains the descendants of more than one MRCA

ABCE

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

Sister group

A

Closest relatives of taxa under study

A and B
AB and C

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

Parsimony

A

Based on Occam’s razor

Minimizes the # of character changes- always picks the shortest possible tree

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

Neighbor joining

A

Builds a tree based on distances between all possible pairs of taxa

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

Maximum likelihood

A

Gives probability that the tree you have fits the model

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

3 types of evidence regarding early forms of life

A
  1. Preserved micro organisms (fossils)
  2. Microbially produced stromatolites
  3. Geochemical signatures-keragen, stable isotopes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Proterozoic era

A

of microfossil species increases rapidly, stromatolites abundant, eukaryotes present, many forms identical to modern Cyanobacteria

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

Phanerozoic era

A

Ediacaran biota appear- tribrachidium

Cambrian explosion, predator prey system, stromatolites decline rapidly, rise of metazoa and plants

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

Marina biota - Cambrian fauna

A

Trilobites, inarticulate Brachiopods, hyoliths

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

Marine biota- Paleozoic fauna

A

Articulate Brachiopods, Crinoidea, corals, Cephalopods, bryozoans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Marine biota- modern fauna

A

Bivalves, gastropods, marine vertebrates, bryozoans, crustaceans, echinoids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Big five mass extinctions

A 
Ordovician
Late Devonian
Permian
Triassic
Cretaceous
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Ediacaran fauna

A

All soft bodied, no skeletons

some with tri radiate symmetry, which is not seen in the modern world like tribrachidium

Dickinsonia

Trace fossils present- show that someone lived on the bottom/ ground link footprints, don’t know what organism it is but tells you there are organisms able to move around

More similar to animals than fungi or algae

Likely to be a poly phyletic assemblage rather than a single class

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Burgess Shale- who discovered it, what is it, what does it say, what animals were discovered

A

Charles Walcott discovered it

Bottom of a steep cliff that was constantly buried with sand, and had low o2 levels, which is perfect for making a fossil

Hallucigenia, pikaia, opabinia, wiwaxia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Cambrian explosion - what is it? What is it not? What was the environment like?

A

First appearance of a large number of skeletonized animal phyla in the fossil record within a short amount of time

It isn’t the origin of animals, or origin of animal body plans, or origin of adaptations that led to colonization of land or the evolution of flight

Increased tectonism and breakup of continents, large shift in strontium curve which increased continental erosion and change in ocean chemistry, two major ice ages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Molecular basis of animal development

A

This is something that is shared by all types of animals

Sequential activation of specific genes by regulatory switches – transcription – protein

The regulatory switches also set up the basic tissue types

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Hox genes/ hox cluster
Many types of genes share a common DNA sequence called a homeobox It's clustered next to each other on a chromosome It's a sequence that specifies the development of diff parts of the body Regulatory switches existed before the Cambrian explosion - and some evolved additionally, which could be specific to certain species. But basic elements are preserved throughout all species
25
Long evolutionary fuse vs potential environmental trigger
Long evolutionary fuse: lineage divergence, hox-gene duplications, evolution of novel morphologies began slowly over time and all came together at Cambrian explosion- more likely Potential environmental trigger: regulatory systems were in place (you could make an animal already) but conditions didn't meet quota - low oxygen levels to support life - suggests an environmental trigger
26
Closest living relative of animals
Choanoflagellates Free living, single cell and colony forming eukaryotes Important predators of bacteria, important component of food webs
27
Simplest and most basal group of animals
Placozoans (don't know exactly where they fit in relative to animals) Sponges Ctenophores (Sponges and Ctenophores are the sister group to cnidarians
28
Placozoans
First found on glass walls of aquarium In tropical and subtropical oceans Not much known about biology and ecology
29
Sponges
Simplest animals A hollow tube of tissue with perforations on the sides (Ostia) and open top (osculum) Water pumped thru Ostia and osculum and the sponge traps particles in the water Lined with choanocytes that produce water flow
30
Cnidaria
Basic body form is a sac - stomach with two layers of cells and an opening which is used as the mouth and butt Colonial and solitary species
31
Bilateria - major clades
Protostomia and deutorostomia
32
Protostomia - clades
Ecdysozoa and lophotrochozoa
33
EcdysozoA
Characterized by ecdysis/ molting Nematodes and arthropods
34
Lophotrochozoa
Lophophorata and trochozoa Mollusk and annelids
35
Lophophorata
All have a lophophore - a feeding organ Phoronids, Brachiopods, bryozoans Bryozoans - solitary animals but are interdependent for the function and survival of the colony Brachiopods- sessile, attached to the substrate
36
Two things needed for suspension feeding? Every suspension feeder needs ?
1. Animal with a separator Particles in suspension 2. A filter Mechanisms to move the medium past the filter Stokes law
37
Types of suspension feeders
Active Passive Facultatively passive - uses both
38
Mechanisms of suspension feeding
Sieving- particles caught by mechanical trapping Aerosol capture - particles caught on adhesive surface of filter Scan and trap - a biologically active response
39
Phylum mollusca
Aplacophora - worm like. No shells Polyplacophora - chitons. Flattened elongated molluscs with a shell that has many plates Monoplacophora- cap shaped shell. Closely related to chitons Gastropoda- mollusks that exhibit extorsion Bivalvia - bilaterally symmetrical Cephalopoda- squids and octopus. Highly active predators, brain well developed. Active swimmers using jet propulsion Scaphopoda- have a tusk shaped she'll open at both ends
40
Non marine molluscs
Land snails. High diversity on tropical islands
41
Echinoderms
Benthic. Have pentaradial symmetry, but evolved from a bilaterally symmetrical ancestor Echinoidea- sea urchins and sand dollars. Aristotles lantern, a structure with 5 hard teeth, used to grind food and scour hard rock Asteroidea- star fishes. Most are scavengers or predators. Lay on top of food then secrete enzymes to digest it Crinoidea- many species with stalks but some have lost it. Trap suspended particles with their arms
42
Characteristics of reefs
Organic network Wave resistance Photic zone restriction Raised relief Tropical (warm water) distribution
43
Relationships in modern coral reefs
Zooxanthallae (algae) provide corals with food and in turn receive nutrients and co2 for photosynthesis
44
Catastrophes of coral reefs
Hurricane Allen- changes reef from stag horn coral dominated to non stag horn dominated Hurricane Hugo - changed coral cover and also affected invertebrates Acanthaster outbreak - a planci ate corals which caused over abundance of algae. And algae eating fish dominated. Could be cuz of loss of predators of a planci or eutrophication caused more phytoplankton which is more food for a planci larvae Coral bleaching - could be cuz of increases in sea surface temperature or solar radiation and UVB. Reproductive and growth output are reduced and eventually the coral die Diadema die off- sea urchins died off. They ate algae so there was an abundance of algae and seaweed
45
Threats to coral reefs
Destructive fishing Overfishing Coral mining Pollution Ship groundings Tourism Disease
46
Arthropods
Growth by ecdysis , ventral nervous system with dorsal brain Two types of appendages - uniramous and biramous Tardigrada - water bears that can survive everything Onychophora- velvet worms that are brightly colored and are carnivorous
47
Cheliceriformes
Body Divided into two - cephalothorax and abdomen Book gills and book lungs
48
Crustacea
Body has a 5 segmented head and trunk is divided into thorax and abdomen Breathe by aqueous diffusion
49
Insects
3 body parts - head, thorax , abdomen Breathe thru trachea and spiracles
50
Why are insects small
Exoskeletons must be small - they're sensitive to damage from impact Molting is not efficient for large size animals. It would be hard to maintain body shape during molt Surface to volume ratio is maximized in small size. Tracheal density constrains body size
51
Decline of invertebrate biodiversity
Agriculture and loss of habitat Loss of wetlands Introduced species Climate change Loss of host
52
Benefits of insects
Pollination Dung burial Food source for wildlife and fish Control of agrocultural pests
53
Charophyceae/ charophytes
Land plants are most closely related to these
54
Features of charophytes that are more expressed in land plants: What do charophytes lack that land plants have?
Sporo-pollenin Cutin Phenolic compounds Well developed sporophytes Sexual organs of the land plants Cuticle and airborne spores
55
Wen did land plants originate ?
Ordovician era Happened cuz of major radiation, which is kind of similar to the Cambrian explosion- involved the origin of most major body plans seen in living plants, increase in species richness relatively small compared to increase in phenotypes, development of impermeable surfaces, and the radiation happened at the same time co2 levels fell and 02 levels rose
56
Consequences of evolution of land plants
Energy and nutrient fluxes Evolution of well developed root systems -- led to acidification of soils-- led to decreasing ca-mg silicate minerals-- led to decrease in co2 in atmosphere
57
Non vascular plants
Mosses, liverworts, hornworts Lack vascular tissue No seeds, flowers, fruits Small in size
58
Higher plants
Have vascular tissue, a complex tissue consisting of multiple cell types
59
Pteridophytes
Ferns and stuff Dominant during Paleozoic but extinct now
60
Gymnosperms
Diverse before angiosperms appeared Cycads, ginkos
61
Angiosperms
Evolved in Cretaceous, dominated since then Monocots, but mostly eudicots
62
Why are angiosperms so diverse?
Biotic pollination-pollen can be delivered efficiently even in small amounts. Insect pollination is unique to angiosperms. Birds and mammals carry the seeds to places the plants can't reach Plant-insect co evolutionary arms race- Insects damaged gymnosperms
63
Problems with the theory that biotic pollination helped angiosperms dominate
Wind pollination is also efficient Wind pollinated species have similar rates of gene flow to insect pollinated ones Living cycads/ gymnosperms insect pollinated and animal dispersed

Biodiversity (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions