Biodiversity Flashcards
0
Q
Colonial flagellate hypothesis
A
We came from a line of colonial flagellates
-Molecular systematics favor this.
1
Q
The multinucleate hypothesis
A
We came from a line of multinucleate ciliates
2
Q
Hox developmental gene
A
Provided a tool that can produce rapid change in body plan
3
Q
Parazoa
A
- lacks symmetry and tissues
- consists only of Porifera (sponges)
- have ability to aggregate and disaggregate their cells
4
Q
Eumetazoa
A
Have symmetry and tissue
5
Q
Diploblastic.
Triploblastic. (For eumetazoa)
A
2 germ layers
3 germ layers
6
Q
Porifera reproduction
A
Asexual- fragmentation
Sexual- egg and sperm meet.
- larval sponges use cilia for swimming.
- settle down on a substrate
- transform into adults
7
Q
Radial symmetry
A
- body parts arranged around central axis
- can be bisected into 2 equal halves in any 2-D plane
8
Q
Gastrodermis
A
Inner layer
9
Q
Epidermis
A
Outer layer
10
Q
Mesoglea
A
In between
- non cellular
- “jelly”
11
Q
Which two phylum are diploblasts?
A
Cnidaria & Ctenophora
- branch out before bilateria
- have radial symmetry and only 2 germ layers
12
Q
Porifera structure & layers
A
- Inner Layer= specialized flagellate cells called choanocytes, or collar cells.
- Central Layer= gelatinous protein-rich matrix called the mesohyl
- calcium or glass spicules
- fibers of protein spongin
•Outer layer= protective layer
13
Q
Filter-feeders
A
Choanocyte flagella draws water through numerous small pores
14
Q
Intracellular digestion
A
Brings in food and oxygen and expels waste
15
Q
Cnidaria
A
- Nearly all marine
- Bodies have distinct tissue but no organs
- Carnivorous
- Exist as either medusae or polyps
- no circulatory, respiratory, or excretory system
16
Q
Polyp
A
•Cylindrical and sessile
- may reproduce sexually or asexually
- budding(asexual)
17
Q
Medusa
A
•Umbrella-shaped and free-living
-Medusae reproduce sexually
18
Q
Extracellular digestion
A
Digestion begins with fragmentation in the gastrovascular cavity
19
Q
Nematocyst
A
Unique specialized cells
- contain a small but powerful harpoon
- used for food acquisition & defense
•located on the epidermis of Cnidarians
20
Q
Ctenophora
A
A small phylum whose members are known as comb jellies, sea walnuts or sea gooseberries.
- propel themselves with 8 rows of fused cilia
- capture prey with a colloblast
- symmetry isn’t strictly radial
- have muscle cells reminiscent of a mesoderm
21
Q
Bilateria
A
Bilaterally symmetrical
-all are triploblastic
22
Q
Bilateral symmetry
A
Right and left halves that are mirror images
23
Q
Cephalization
A
Evolution of a definite brain area
24
Triploblastic layers
Inner endoderm
-gut lining
Outer ectoderm
-skin and nervous tissue
Middle mesoderm
-muscle and bone
25
Acoelomates
No body cavity
26
Pseudocoelomates
Body cavity between mesoderm and endoderm
27
Coelomates
Body cavity entirely within the mesoderm
•called the coelom
28
Blastula
•Hallow ball of cells
-zygote divides to form a blastula
29
Blastopore
Opening to outside
-blastopore becomes an opening to the digestive system
30
Protostomes
Develop the mouth first from the blastopore
31
Spiral cleavage
Cells "move" as they divide
-occurs in the subgroup spiralia
32
Determinate development
* Embronic cells will form specific body regions
| * removed one embronic cell, and development ceases
33
Origination of coelom
- Forms from splitting the mesoderm
| - Not all protostomes have one
34
Spiralians
- Grow by adding mass to an existing body
| - Obvious spiral cleavage
35
Platyhelminthes
• The flatworms are soft-bodied animals
- Acoelomates
- Move by ciliated epithelial cells
• 3 Major Classes
- Turbellaria (Free-living)
- Trematoda (Parasitic)
- Cercomeromorpha (Parasitic)
36
Turbellaria
* Free-living flatworms
| * Found in freshwater, marine, and even terrestrial environments.
37
Cercomeromorpha
• Tapeworms
-Live as parasites within the bodies of other animals
• Most species occur in the intestines of vertebrates
- Absorb nutrients through their skin
38
Trematoda
• Flukes
• Live as ecto or endo-parasites in the bodies of other animals.
-Attach by suckers, anchors, or hooks
• Life cycle involves 2 or more hosts
39
Rotifera
* "Wheel animals"
* Pseudocoelomates
* Spiralia
* Complex internal organs
• Rapidly beating thick cilia at their heads (Corona)
-Corona may be used for transport or funneling in food.
40
Mollusca
• 2nd most diverse phylum
- Include snails, slugs, clams, octopuses, etc.
- Most have remained in the ocean
41
Mollusk Body Plan
• Except for Cephalopods, all mollusks have an open circulatory system.
-Organs bathes in blood and lymph
* The muscular foot of a mollusk is adapted for locomotion, attachment, and food capture.
* Have mantle
* Most produce a calcium carbonate-rich shell
42
Mantle
Epidermis that covers the dorsal side of the body
-Forms a cavity which houses the respiratory organs and the opening of excretory, reproductive and digestive organs.
43
Classes of Mollusks
- Polyplacophora
- Gastropoda
- Bivalvia
- Cephalopoda
44
Polyplacophora
•chitons
- marine mollusks
- oval bodies with 8 overlapping dorsal calcareous plates
- most are grazing herbivores
45
Gastropoda
•snails and slugs
-primarily marine
- Pairs of tentacles with eyes at the ends
- undergo torsion and coiling during embryological development
46
Torsion
Mantle cavity and anus are moved from the posterior to the front
47
Coiling
Spiral winding of the shell
48
Bivalvia
•clams, scallops, mussels, oysters, and others.
- have 2 lateral(left/right) shells hinged together dorsally
- sessile filter-feeders
- water circulation is mediated by siphons and rhythmic beating of cilia on gills
49
Cephalopoda
•active marine predators
•foot
-series of arms equipped with suction cups
•have highly developed nervous systems
-complex behaviors and high level of intelligence
•can change color
50
Annelida
* Annelid worms always exhibit segmentation
* The front segments contain specialized sensory organs
* a ventral nerve cord connects at the ganglia in each segment with each other and the brain
- move using their coelom as a skeleton
- closed circulatory system
- exchange o2 and CO2 through their body surfaces
2 classes: Polychaeta and Clitellata
51
Polychaeta
Mostly marine worms
-have differentiated head
•have paired parapodia on most segments
-used in swimming, burrowing, crawling.
- 2 sexes
- many live in tubes
52
Clitellata
•Earthworms- mostly terristrial. Live underground.
- lack eyes and head
- move through soil using chaetae
•hermaphroditic
-secretes mucus that holds the work together during copulation
•leeches
53
Chaetae
Little chitinous bristles that anchor soil
54
Ecdysozoans
Increase in size by molting their external cuticles or skeletons
55
Nematoda
•roundworms comprising many species
-in marine, freshwater, and soil habitats
* bilaterally symmetrical
* segmented
* pseudocoelomates
* lack a defined circulatory system
* flexible, thick cuticle.
* lack specialized respitory organs and exchange oxygen through their cuticles
56
Arthropoda
•Arthropods are most successful animal (2/3rd of all species)
-about 80% are insects
57
Arthropod morphology
- have jointed appendages
- have an exoskeleton made of chitin and protein
•bodies are segmented
-some segments are fused into tagmata
* open circulatory system
* compound eyes or ocelli
-periodically undergo ecdysis
58
Ecdysis
Shedding the outer cuticle layer of exoskeleton
