Do you have a multiple choice of the word "these"? It would be easier for me to help you...
1. skin tears saliva stomach acid with all produce friendly bacteria. 2. active immunity is when one has a disease or live pathegon and is immune to it afterwards. unlike passive immunity
Answer:
True
Explanation:
Cell cycle checkpoints are an important layer of control of the cell cycle. The cell cycle is a process by which cells divide.
There are 4 stages of the cell cycle G1, G2, S and M.
When the cell goes through the cell cycle, each stage has different processes that must occur for the cell to properly divide. During G1, the cell must grow to sufficient size and the environment must be favorable for cell division. During S phase, all the DNA must be properly replicated. during G2 the cell must prepare for division. During M, the cell actually divides.
There are 3 checkpoints throughout the cell cycle. The G1 checkpoint ensures the cell has reached sufficient size. The G2 checkpoint ensures the DNA has been properly replicated. The M checkpoint makes sure the chromosomes are properly attached to the spindles to split the DNA between 2 new cells.
Without these checkpoints, the cell can divide uncontrollably which can lead to cancer.
It was critical.. As you know cells are microscopic and cannot be seen with the naked eye. Without a microscope it probably wouldn't have been discovered.
Grafting is used most often for vigorous rootstocks that do not produce good quality fruit or flowers.
- - Final answer: C
