Chapter 3 Section 5 Flashcards
Describe the cell cycle
??
What occurs in the first stage of the cell cycle: Interphase
The cell grows and chromosomes are duplicated through the process of DNA replication. (See Mitosis notes page)
Explain replication
DNA makes a copy of itself.
DNA replication is the cell’s process of making a copy of its DNA during INTERPHASE right before entering mitosis. This way when the cell splits in 2, both new cells have the right amount of DNA.
The 2nd stage of the cell cycle is called
Mitosis
What occurs during mitosis?
The cell’s nucleus is divide into 2 new nuclei
What are the 2 rod structures that contains the cells DNA called?
Chromosome
What is each rod called?
Chromatid
Mitosis is divided into 4 parts. Name and describe those parts.
Prophase: the nuclear membrane begins to dissolve.
Metaphase: the chromosomes line up at the equator of the cell.
Anaphase: the chromatids separate and move to opposite sides of the cell.
Telophase: a nuclear membrane forms around each set of chromosomes and the chromosomes unwind.
Name and describe the 3rd stage of the cell cycle
Cytokinesis: the cell pinches into 2 new cells
Contributions from Scientists:
Franklin
used x ray to see DNA
Contributions from Scientists:
Chargaff
said that A=T and G=C
Contributions from Scientists:
Watson & Crick
made a model of DNA
The structure of DNA is described as a _____. It is made out of many smaller______ linked together. A ____ is a subunit of DNA.
Twisted ladder
Nucleotides
Nucleotide
Nucleotides are made of:
Ladder sides:
Ladder rungs:
Phosphate and Sugar
base
List the 4 bases (be sure to list which are complimentary)
Adenine=Thymine
Guanine=Cytosine
DNA replication is the cell’s process of making a copy of its DNA during ______ right before entering mitosis. This way when the cell splits in 2, both new cells have the right amount of DNA.
INTERPHASE
4 steps of DNA replication
A. Proteins unwind the DNA
B. DNA is split down the middle by proteins
C. complementary strands are added to both sides of the open DNA. The final result is 2 helices, each containing a OLD strand and a NEW strand.
D. The DNA is then rewound by proteins.
How many meters or feet of DNA does each cell contain
6-8 feet
How does a single cell fit the entire DNA into the nucleus?
It winds up tightly.
