Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

General Biology: OrganismL Biology and Evolution - Set 1 > Invertebrates radiata > Flashcards

Invertebrates radiata Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

How many phyla are animals grouped into?

A

35 phyla (but we only focus on about 15 phyla)

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

What do invertebrates lack?

A

Backbones

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

How many known species do invertebrates account for?

A

They account for 95% of known animal species
- Vertebrates comprise only ~5% of animals

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

What kinds of habitats do invertebrates inhabit?

A

They inhabit nearly all environments, though most are aquatic, mot marine
- Terrestrial habitats pose special problems for animals - primarily because of desiccation
- Only vertebrates and arthropods have great diversity on land

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

What are sponges?

A
  • Basal animals that lack true tissues
  • Porifera (“pore bearer”)
  • Sponges are sedentary animals from the phyla Calcarea and Silicea (once thought to be plants)
  • Have no nerves or muscles (an exception)
  • Lack true tissues and organs, loose federations of unspecialized cells
  • Possess choanocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the three main classes of sponges?

A

Glass sponges
- Siliceous spicules
Demosponges
- Most diverse (~90% of living sponges)
- Have a collagen-based skeleton
Calcareous sponges
- Calcium carbonate spicules

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

Where do most sponges live?

A

Most are marine; oly ~100 species live in fresh water

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

How does the body of sponges work?

A
  • The body of a simple sponge resembles a sac perforated with holes
  • Water drawn into the spongocoel, expelled through the osculum
  • Complex sponges have branched canals and several oscula
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do sponges feed?

A

They suspension-feed
- Flagellated choanocytes (collar cells) lining the spongocoel create water flow through the sponge & trap food with their collars

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

What is the structure of a sponges body?

A
  • Pinacocyte forms the outer covering of the sponge; may phagocytize large food particles
  • Oocyte egg cell
  • Lophocyte or collenocyte secretes collagen
  • Porocyte controls water flow through ostia
  • Amoebocyte delivers nutrients to cells, and differentiates into other cell types
  • Sclerocyte secretes silica spicules
  • Choanocyte generates water current and filters food particles from water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do sponges reproduce?

A
  • Most sponges are hermaphrodites, individuals produce both sperm and eggs (generally sequential hermaphrodites)
  • Gametes arise from choanocytes or amoebocytes
  • The eggs are typically retained, but sperm are carried out the osculum by the water current
  • Sperm are drawn into neighboring individuals and fertilize eggs in the mesohyl
  • The zygotes develop into flagellated, swimming larvae that disperse from the parent
  • When a larva finds a suitable substratum, it develops into a sessile adult
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Are sponges capable of regeneration?

A

yes, sponges are capable of extensive regeneration, the replacement of lost parts

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

What health benefits do sponges have for humans?

A
  • Sponges produce a variety of bioactive metabolites such as antibiotics and other defensive compounds
  • Cribrostatin 6 isolated from marine sponges can kill penicillin-resistant strains of the bacterium Streptococcus
  • Cribrostatin 4 is a potent anti-cancer agent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Who won the nobel prize in chemistry in 2010 and why?

A

Richard Heck, Ei-ichi Negishi and Akira Suzuki for palladium-catalyzed cross couplings in organic synthesis”
- Palladium-catalyzed cross coupling reactions key for synthesizing complex organic molecules in lab
- Scientists now are able to make anti-cancer drug discodermolide in labs

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

The origins of what is traced to sponges?

A

The origin of nerves
- Search of the genomic sequence of the sponge Amphimedon queenslandica reveal existence of core neurological genes
- Neurological genes expressed in the globular cells found in epithelia of larvae
- Globular cells have protrusions out into environments and may represent rudimentary sensory organs

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

What was found about the internal composition of Trichoplax adhaerens and what did it suggest?

A
  • They have just 4 cell-types and lack a stomach, muscles, nerves, and gonads - no organs
  • Its genome contains ~11,514 protein-coding genes many which are counterparts (orthologs) to genes essential for organogenesis in more complex organisms
  • Suggests that many genes have a deep evolutionary history
17
Q

What phyla do all animals except sponges belong to?

A

Eumetazoa, animals with true tissues

18
Q

Phylum Cnidaria

A
  • The cnidarians (hydras, jellies, sea anemones, and coral) have a relatively simple radial body plan that arose 570 mya in the Ediacaran biota
  • Most are marine
  • The basic cnidarian body plan is a sac with a central digestive compartment, the gastrovascular cavity
  • A single opening to this cavity functions as both mouth and anus
19
Q

Polyp & Medusa

A

Two variations on a basic body plan, one sessile (polyp), the other floating (medusa)
- Cylindrical polyps adhere to substratum by the aboral end, extend tentacles, and wait for prey
- Medusas (also called jellies) are flattened, inverted versions of polyps that drift passively and by contacting their bell-shaped bodies

20
Q

Cnidarians are carnivores

A
  • Cnidarians use tentacles around the mouth to capture prey and push food into the gastrovascular chamber for digestion
  • Batteries of cnidocytes on the tentacles for defense or prey-capture
    - Organelles called cnidae evert a thread that can inject poison into, stick to, or entangle prey
  • Cnidae called nematocysts are stinging capsules
21
Q

How does the stinging of the nematocysts work?

A
  • Discharge is very fast, microseconds
  • Nematocysts are triggered when adjacent chemo and mechanoreceptors are triggered
  • Nematocysts must be replaced once fired
22
Q

What is special about anemone fish?

A
  • They exist in a mutual symbiosis with anemone
    • Fish defends host and uneaten food and feces
      feed the anemone
    • Slow moving fish get protection from host
  • Avoids being stung by having a sugar-based mucous coating
23
Q

Muscles & Nerves

A
  • Muscles and nerves exist in their simplest forms Epidermal & gastrodermal cells have contractile fibers of bundled microfilaments
    • True muscles appear first in triploblastic animals
    • With mouth closed, the gastrovascular cavity acts
      as hydrostatic skeleton for contractile cells to
      work
  • Movements are controlled by a non-centralized nerve net associated with simple, radially distributed sensory receptors
  • Can respond to stimuli from all directions
24
Q

What are the four main classes of Cnidarians?

A
  • Hydrozoa (Portuguese man-of-war, hydras, Obelia, some corals)
  • Scyphozoa (jellies, sea nettles)
  • Cubozoa (box jellies, sea wasps)
  • Anthozoa (sea anemones, most corals, sea fans)
25
Q

What are the three possible life histories of cnidarians?

A
  • Some cnidarians exist only as polyps
  • Some exist only as medusas
  • Others pass sequentially through both a medusa stage and a polyp stage in their life cycle
26
Q

Hydrozoan Life Cycle

A

Most hydrozoans, e.g. Obelia, alternate between asexual polyps and medusa sexual stages

27
Q

Hydras

A

One of just a few freshwater cnidarians
- In favorable environments, reproduces asexually by budding, forming outgrowths that pinch off from the parent
- In poor conditions, they reproduce sexually to produce resistant zygotes
- They have profound regeneration capacities

28
Q

Medusa-dominated life cycles

A
  • The medusa generally prevails in the life cycle of the Cubozoa & Scyphozoa
  • The medusas of most species live among the plankton as jellies
  • Costal scyphozoans have small polyp stages during their life cycles
    • Jellies that live in the open ocean generally lack
      the sessile polyp
29
Q

What’s so dangerous about cubozoa box jellyfish?

A

Toxins attack the heart, nervous system, and skin 1000’s deaths by drowning attributed to stings

30
Q

What is the Anthozoa phylum mainly comprised of?

A

Anemones and corals
- All occur only as polyps

31
Q

Corals

A

Solitary or colonial forms and secrete a hard skeleton of calcium carbonate
- Each generation builds on the skeletal remains of earlier generations to form what eventually becomes a coral reef

32
Q

Sexual reproduction

A
  • 75% of hard corals are hermaphrodites
  • Most hard corals “broadcast spawn” releasing eggs and sperm into the water
  • Event is synchronized by lunar cycle
  • Mass spawning events may explain the high rate of hybrid formation amongst corals
33
Q

What was discovered after the completion of the Nematostella genome sequence in 2007?

A

The genome shared remarkable ‘synteny’ with human genome, ie. many segments of genome with conserved gene order
- Compelling evidence for shared ancestry of eumetazoans

34
Q

Who won the nobel prize in chemistry in 2008 and why?

A

Osamu Shimomura, Martin Chalfie and Roger Tsien for the initial discovery of GFP and a series of important developments which have led to its use as a tagging tool in bioscience
- By using DNA technology, researchers can now connect GFP to other interesting, but otherwise invisible, proteins
- This glowing marker allows them to watch the movements, positions and interactions of the tagged proteins

35
Q

Where is GFP found?

A

It is isolated from the jellyfish Aequorea victoria
- used as a reporter of gene expression in molecular biology

36
Q

What is the difference between fluorescence and bioluminescence?

A
  • In fluorescence, energy from a light source is absorbed and re-emitted as another photon
  • In bioluminescence is light produced by a chemical reaction, also used by many cnidaria
37
Q

Ctenophora

A

Named for their eight rows of comb-like plates composed of fused cilia which are used for movement
- Most comb jellies have a pair of long retractable tentacles
- These tentacles are armed with adhesive structures (colloblasts) that secrete a sticky threat to capture food

38
Q

What are some distinctive characteristics of ctenophores?

A
  • Diploblastic with ectoderm and endoderm but have a middle layer called a mesoglea made of collagen
  • Tentacles covered in filaments called tentilla which contain colloblasts which lasso prey (do not possess nematocysts)
  • Some species are spherical or ovoid, others are elongate and ribbonlike

General Biology: OrganismL Biology and Evolution - Set 1 (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions