Mr. morales is teaching a lesson on classification. he says that spiders are classified as a different group than insects because they have eight legs instead of six legs. he explains that spiders evolved first , mr. morales also says that having eight legs is the derived trait that seperates the two groups. antonio thinks mr. morales is wrong. which piece of information is antonio considering ?

Hello! Your answer is

Quote:

The correct answer is If spiders evolved first, six legs is the derived trait.

The teacher says that the insects have six legs and the spiders have 8 legs, but the spiders derived this trait and evolved prior than the insects.

The student thinks that the teacher is wrong because he thinks, of the spiders evolved first, the  the insects must have derived the 6 leg trait later in the evolutionary history. hence, the 6 leg trait should be derived trait, not the 8 leg trait.

answer and explanation;

volcanic rocks are igneous rocks which form from lava, molten rock which has been thrust out of a volcano onto the surface of a rocky body such as an asteroid, planet, or dwarf planet.  

plutonic rocks are igneous rocks which form from subterranean chambers of molten rock or magma. plutonic rocks make up the base of continental crust as well as oceanic crust. their slow rate of formation causes them to be coarse grained since there is plenty of time for large crystals to form before the magma solidifies into rock.

the textural difference is that plutonic rocks are more coarse grained than volcanic rocks. plutonic rocks are coarse grained while volcanic are fine grained ; glassey or fragmental. since fine and coarse are adjectives the decision as to whether a rock is fine or coarse grained is generally made on the bases of whether or not the individual crystals can be seen in most if the rock.