The correct answer is - D) covered by warm shallow seas.
The fact that the crinoids are have an abundance in the fossil records in Pennsylvania in the Mississippian Period, tells us that this area was covered with shallow and warm seas. The reason why we can get that conclusion is that the crinoids live only in that kind of environment, so it simply a logical conclusion.
The geological data is also confirming this, as it is easily noticeable in the layers that during this period of the geologic past, what is now Pennsylvania, was covered with shallow sea waters. Also, this waters were warm too, as the climate was warm and humid and that period, so it was a perfect environment for the crinoids to flourish.
All of the above, here's an explanation. The sun helps the water cycle due to evaporation which causes it to turn into a steam/gas. Now for wind, it's because the sun heats up the air and causes thermal energy which later turns into wind. And finally, weather, obviously the sun evaporates water which causes it to be rainy/drowsy.
Specialized structures for reproduction: One example is a fruiting body. Just like a fruit is involved in the reproduction of a fruiting plant, a fruiting body is involved in the reproduction of a fungus. A mushroom is a fruiting body, which is the part of the fungus that produces spores (Figure below
I believe it would be C) Cellulose. As this is one of the essential components found in the cell wall of plant cells.
Answer: 2 electrons
Explanation:
The inner shell (1st shell) can hold 2 electrons, the next shell can hold 8 electrons and the third shell can hold 18 electrons.
