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.
Answer: 32 chromosomes, they are clones of the parent drone
Explanation:
The production of offspring drones without fertilization means that offspring that are produced are produced by mitosis, which results in daughter cells that are clones of the parent. They have the same amount of chromsomes as the parent drone, which is 32.
Answer:
<em>The correct option is C) It does not depend on insect pollination.</em>
Explanation:
Angiosperms can simply be described as the plants which produce flowers whereas gymnosperms are the plants which do not produce flowers.
Both, the gymnosperms and the angiosperms, are capable of producing seeds. However, the seeds of the angiosperms are enclosed in an ovary. The seeds of gymnosperms are not enclosed.
<u><em>One of the major differences between gymnosperms and angiosperms is that the angiosperms have to depend on animals for pollination. On the other hand, the seeds of gymnosperms are spread through the wind and are pollinated.</em></u>
<h2>Xylem;phloem and cork</h2>
Explanation:
Wood is mainly known as secondary xylem found in trees
- Xylem is basically the vascular tissue which is responsible for the conduction of water and nutrients from the roots to shoots and leaves
- Secondary xylem is formed from secondary growth and is associated with lateral growth and grows from the vascular cambium
- Its cell walls are thickened by deposition of lignin which provides mechanical support to plants and consists of tracheids and vessels that are shorter and wider
- In large woody plants secondary xylem get differentiated into heartwood and sapwood
Bark is essentially made of phloem and cork
- Bark sole purpose is to provide protection to trees
- The inner bark is produced by vascular cambium which consists of secondary phloem whose innermost layer transports food from the leaves to rest of the plant
- The outer bark is a dead tissue which is the product of cork cambium
