Quiz#6-metazoa. sponges, cnidiria, bilateroa. mollusca, annelida Flashcards Preview

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Flashcards in Quiz#6-metazoa. sponges, cnidiria, bilateroa. mollusca, annelida Deck (27)
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1
Q

what evidence supports the hypothesis that animals are a monophyletic group?

A

phylogenetic analysis of gene sequences(of genomes) give evidence of this.Also it is said that all animals descended from ancestor containing unique cell junctions and proteoglycans in extracellular matrix

2
Q

radial cleavage

A

the first few divisions of the fertilized egg(zygote) where there is an even pattern and complete distribution of yolk(celll nutritive material nourishing embryo) w/in the egg…this radial cleavage is an ancestral condition for animals except sponges.

3
Q

spiral cleavage

A

a complicated permutation of radial cleavage

4
Q

cleavage

A

the first few divisions of the zygote cell…causing the number of cells in the embryo to double after each cleavage.

5
Q

hox genes

A

specify body pattern and axis formation , leading to the developmental similarities across animals

6
Q

Proteoglycan

A

extracellular matrix molecules that consititute on synapomorphy of animals

7
Q

collagen

A

extracellular matrix molecules also found in ancestor of animals.

8
Q

diplobasty

A

as animals conitnued to develop… cell layers differentiated and animals with diplobasty contained embryos with two cell layers…the ectoderm and endoderm…this exhibits the ancestral condition

9
Q

triplobasty

A

animals with embryos that contain 3 layers ..the ectoderm, mesoderm, and endoderm…this is a synapomorphy of triploblastic animals(placozoans, ctenophhores, cnidarians)…

10
Q

gastrulation

A

early development in animals in which a hollow ball(one cell thick) forms and indentation that then forms a cup shaped called blastopore

11
Q

prostostomes

A

one of the two main groups that are contained within the triplobastic orgnamisnsm that undergoes gastru;ation.. In the prostostomes..the mouth arises frm the blastopore and the anus forms later

12
Q

deuterostome

A

second main gropup within the triploblastic. This group in which the anus forms first and the mouth will form later,

13
Q

body plan

A

animal general structure and arrangement of organs and functions of the various parts…animals share body plans but can vary tremendously on four features, symmetry, body cavity(any fluidfilled space within multicellular organism), body segmentation, external appendages

14
Q

coelom

A

body cavity(fluidfilled space) Enclosed on the inside and outside by mesoderm allowing for better control over the animals movement of fluids.

15
Q

segmentation

A

division into different parts of body allowing for specialization of different regions and also allows body to alter shape, to increase body movement.

16
Q

sponges

A

are the simplest of animals, with no symmetry, no true organs and no distinct embryonic cell layers,only , a few specialized cells…they have a body plan built from an aggregation of cells built around a water canal system…..where water and food is absorbed by the sponge.//..can be filter feeders or carnivores…both asexual and sexual reproduction….

17
Q

spicules

A

hard sponge skeletal structures that may be simple and small or large and complex…some may be very flexible

18
Q

choanocytes

A

are cells in sponges that capture food particles

19
Q

cnidarians

A

organisms such as sea anemonie, jellyfish, that have a mouth connected to a blind sac called gastrovascular cavity that aids in gas exchange, circulation, digestion, and hydrostatic skeleton…the cnidarians have both sessile and motile life stages…they are specialized carnivores that use toxin in their nematocysts to capture prey

20
Q

gastrovascular cavity

A

that aids in gas exchange, circulation, digestion, and hydrostatic skeleton..the opening serves as both anus and mouth

21
Q

ployp stage

A

sessile stage in the cnidarians where stalk(stem) is attached to a substratum…mature polyps will develop into medusae through asexual budding

22
Q

medusa

A

the motile stage of the cnidarians …that is free swimming and shaped like an umbrella(jellyfish)

23
Q

planula larvae

A

the fertilized egg that develps into freeswimming cilliated larvae that will go on to become a polypse and then a medusa

24
Q

Trochophore larvae

A

The larvae form of the lophotrochozoan clade that uses ciliia for locomotion bringing plankton closer to larva that can then ingest the plankton…these are among the major groups of the clade along with annelids ,mollusks,ribbon worms,and bryozoans

24
Q

osculum

A

mouth opening in sponge, used to expel water.

25
Q

Exoskeletons

A

Cuticles(external covering) of mostly arthropods thst finction as external skeletons..thickened by layers of protein and strong waterproof pokysaccaride called chitin…those with these skeletons cant move in wormlike manner nor use cilia for locomotion…it can also impede passage of oxygen and nutrients…thats why these orgnsms evolved new mechanusms..

26
Q

Foot,visceral mass, mantle

A

3shared parts of the mollusks….

1) foot is a large muscular irgan that originally was the organ of licomotion and support..but has now been modufied to arms ir tentacles…it can also be reduced in some groups
2) the ventral