Answer:
These structures that protect the sponges from most predators, but not turtles, are spicules.
Explanation:
Sponges <em>skeleton</em> is composed of <em>calcium carbonate and siliceous</em> micro-structures called <u>spicules</u>. Their morphology is so varied that it is used in taxonomy for identification and classification.
There are different kinds of spicules:
- <em>Monoaxonic spicule</em>: needle-shaped, straights or curves
- <em>Tetraxonic spicules:</em> they have four prolongations
- <em>Triaxonic or Hexaxonic spicules</em>
- <em>Poliaxonic spicules </em>
Two terms can be applied to any of these spicules kinds:
- <em>Megaspicules</em>: They are elongated and compose the main architecture of the sponge skeleton
- <em>Microspicules</em>: Variable in shape and size, with ancillary functions
Sponges have few predators thank to the spicule structures and their high toxicity. Many of them are capable of perforating soft tissues and producing urticant substances.
Answer: They may be prokaryotic is false.
Explanation:
Protists are eukaryotic organisms i.e they have membrane bound organelles and Nucleus. They are neither plants,animals or fungus. Protists have many form of nutrition and they may be aerobic or anaerobic.
Some protists photosynthesized like algae while others are heterotrophs
They may be unicellular or multicellular.
Some protists have cell walls while others don't.
Plant relies on the sun and we relie on the plants
Yes, this is correct!
Let's imagine two systems, one with 50 species and one with 4000. Both of them experience a draught and as a result 25 species of the first one die (that's quite likely) and 800 of the second population die out (more would not be very likely).
So the first one lost 50% of species and the second one 20% - that means that the second one, with greater biodiversity has a bigger stability:)
