Answer:
Eukaryotes:
-Organisms with a well defined nucleus are known as eukaryotes. such cells are called as eukaryotic cells.
- Their nucleus is enclosed within the nuclear membrane.
- They do not posses a mitochondria.
- The cell wall is the outer most layer of a eukaryotic cell (only plant cells have a cell wall)
- The cells are divided by a process called mitosis.
Eg: Plants, Animals.
Prokaryotes:
- Organisms without a well defined nucleus are known as prokaryotes. Such cells are called as Prokaryotic cells.
- They lack nuclear membrane.
- Mitochondria, Golgi bodies, chloroplast and lysosomes are absent.
- The genetic material (DNA) is present on the chromosome.
Eg: Every organism coming under the kingdom monera.
Explanation:
Question : T<span>he humpback whale can be seen off the coast of Alaska during the summer months, but is found as far south as California and Hawaii during the winter. Why would the humpback whale most likely spend the summer months off the coast of Alaska?
Answer : The humpback whale likes being in the cold like all other fishes.
The humpback whale is usually found around the coast of Alaska because it is a little colder over there. Then in winter it is found around Hawaii and California because the pacific ocean cools down and is not so hot anymore!
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Answer;
D) Linnaeus primarily used physical characteristics.
Explanation;
-Carolus Linnaeus developed naming system that is still used today, called binomial nomenclature. He is known as the Father of Taxonomy, which is the system of classifying and naming organisms.
-Among is contribution is the development of a hierarchical system of classification of nature, which includes eight taxa: domain, kingdom, phylum, class, order, family, genus, and species.
-However, some of Carl Linnaeus's classifications of organisms were incorrect because Linnaeus primarily used physical characteristics.
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.
