Chapter 5.1 Flashcards
What does cell replacement mean?
Your cells continue to divide as you grow
What happens to your body after puberty?
Your body growth slows down but your body will continue to replace cells that take on a lot of “wear and tear”
What is the life span of skin cells?
20 days
What is the life span of stomach lining cells?
2 days
What is the life span of red blood cells?
120 days
What is the life span of brain cells?
30-50 years
What are the 3 stages of the cell cycle?
Interphase, mitosis & cytokenesis
What is interphase?
The first and longest stage of the cell cycle. It is made up of 3 phases
What are the 3 phases of interphase?
Growth & preparation, DNA replication, continued growth and preparation
What happens in the first stage: growth and preparation?
The cell increases in size and makes necessary proteins and some organelles begin to duplicate
What happens in the second stage: DNA replication?
DNA unwinds and seperates. Each side becomes a new template on which a new side forms. The cell then temporarily has 2 sets of DNA.
The process is controlled by enzymes.
What happens in the third stage: continued growth and preparation?
The cell continues to grow and actively makes proteins for the new cell after division.
Chromatin contains the replicated DNA, which is copied into RNA for protein synthesis.
Organelles are also duplicated.
What is mitosis?
The second and shortest stage of the cell cycle.
It is the process in which contents of a cell’s nucleus divides.
What are the results of mitosis?
It results in 2 daughter nuclei, each with the same number and kinds of chromosomes as the parent cell
What happens next to the DNA molecules that replicated during interphase?
As the nucleus prepares to divide, DNA molecules join together to form the sister chromatids of a chromosome