Answer:
Explanation:
An element only has <u>one</u> type of atom and cannot be broken down by chemical means.
Let's analyze the answer choices.
1. This has two types of atoms, so it cannot be an element. It has more than one type of atom.
2. This has two types of atoms that are bonded together. It cannot be an element because there is more than one type of atom and the bonds can be broken.
3. This has one type of atoms, so it is an element.
Therefore the best answer choice is 3.
The correct answer is: A checkpoint will be activated if the spindle does not attach to a kinetochore.
Prokaryotes, do not undergo mitosis (like eukaryotes) and therefore have no need for a mitotic spindle. Prokaryotes also don’ t have checkpoints foor the regulation of cell division.
Normal eukaryotic cells (unlike cancer cells), move through the cell cycle in a regulated way in order to make sure that cells don't divide under conditions that are unfavorable for them. Information about their own internal state (nutrients, signal molecules, DNA integrity) is signal to go or not to go through the cell division. Because of that there are few checkpoints in the cell cycle at which the cell examines the signals and makes a “decision”. The major checkpoints are:
• The G1- the first point at which it must choose, once it passes the G1 checkpoint the cell enters S phase
• The G2-the cell checks DNA integrity and checks if replication is done well.
• The spindle checkpoint-at the transition from metaphase to anaphase.
Answer:
Meiosis takes place in germ line cell.
Invovled in reproduction.
Explanation:
Human evolution known to be a process in which species adapt to certain
conditions of life, and in the battle of life and death, they are forced
to become stronger in order to survive in this world. Diseases have
always been present during the evolution, acting themselves as a natural
selectors - the weaker organisms get sick and die. Not just humans, but
all species have to establish a great protecting mechanism in order to
survive. That is how our bodies are built, to be able to withstand and
survive in the conditions we live in, and that is why our immune system
has to be taken care of.
