Answer:
The main function of the meristem is to trigger the growth of new cells in young seedlings at the tips of roots and shoots and forming buds.
Answer:
umm I can't understand this I'm very very sorry but please put me on the brainliest
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:
D. archaeal membranes contain L-glycerol.
Explanation:
Archaea and eubacteria differ from each other with respect to the nature of membrane lipids. Lipids present in the membranes of the archaeans have the hydrocarbons derived from isoprene units. These hydrocarbons are branched and are attached to the glycerol with help of ether linkage. Ester linkages are present in eubacteria. The glycerol present in the archaeans is L- glycerol. Bacterial membranes have D-glycerol present in their lipids.