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.
<h2>Clonal Selection to a Phosphorylation Cascade </h2>
Clonal selection describes the roles of compartments of the privileged operation in reply to specific antigens attacking the basis in immunology. A phosphorylation cascade is a series of situations wherever one catalyst phosphorylates is different. It makes a succession reactions driving the phosphorylation of thousands of proteins. This can be observed in omen transduction of hormone communications.
Answer:
The glenoid cavity is where the d. humerus articulates with the scapula.
Explanation:
The scapula is the bone that contains the glenoid cavity. The glenoid cavity is a part of the shoulder. This cavity forms the glenohumeral joint along with the humerus. The Humerus is a long bone of the upper arm, and the scapula articulates with this bone to form a ball and socket joint at the shoulder. These are all bones forming the shoulder girdle and upper extremities.
Answer:
1. Are usually single-celled.
2. Do not contain membrane-bound organelles
3. Have DNA located in cytoplasm
Explanation:
Prokaryotic cells are single-celled organisms which have the following characters:
1. They lack a true nucleus and hence, they do not have their genetic material enclosed in a nuclear membrane-bound nucleus, rather it is present in the cytoplasm.
2. They lack all the membrane-bound organelles such as mitochondria, endoplasmic reticulum, etc.
3. They are usually. very small in size and hence are microscopic.
Examples include all the bacterias.
