DNA
and the Cell Cycle
Primary TEKS Supported
5A – [Reporting Category 1] – describe the stages of the cell cycle, including deoxyribonucleic acid (DNA)
replication and mitosis, and the importance of the cell cycle to the growth of organisms
5D – [Reporting Category 1] – recognize that disruptions of the cell cycle lead to diseases such as cancer
6A – [Reporting Category 2] – identify components of DNA, and describe how information for specifying the
traits of an organism is carried in the DNA
6B – [Reporting Category 2] – recognize that components that make up the genetic code are common to all
organisms
TEKS Also Supported
4B investigate and explain cellular processes, including homeostasis, energy conversions, transport of
molecules, and synthesis of new molecules [DNA]
Contents of This Packet
I. Review and Practice
II. Vocabulary Cards
III. Practice Items
IV. Sapling Instructions
The Cell Cycle: Living organisms are made up of cells. Cells grow through the “cell cycle.”
1. There are three phases of the Cell Cycle:
a. Interphase: The majority of a cell’s life Note:
Interphase: cell goes through normal cell
i. G1—The cell goes through normal growth and function
life function/job
ii. S – DNA is replicated
iii. G2 – The cell prepares for Mitosis Mitosis: when the nucleus divides
b. Mitosis: The nucleus of a cell divides Cytokinesis: When the cell divides
i. Prophase: DNA condenses into chromosomes
ii. Metaphase: chromosomes line up in the center
iii. Anaphase: chromosomes are separated to opposite poles of the cell
iv. Telophase: nucleus finishes dividing
c. Cytokinesis: The cell completely divides into two daughter cells
2. Disruptions in the cell cycle are when the cell loses control of cell division and cannot stop dividing‐‐ Which
results in abnormal cell growth called tumors = cancer.
Mitosis vs. Meiosis: Mitosis creates body cells; Meiosis
creates gametes sperm and egg
Mitosis Meiosis
# of divisions 1 2
# daughter cells 2 cells 4 cells
Genetic Make up Identical Unique
Type of cell created Diploid (2n) Haploid (n)
Type of reproduction Asexual Sexual
Examples Skin, Hair Sperm, Egg
1. Mitosis creates 2 identical daughter cells that are body
cells, like skin cells.
2. Meiosis creates 4 genetically different daughter cells, like sperm or egg. Each cell has ½ the number of
chromosomes because a sperm from dad and an egg from mom will combine to create a baby—which the full
number of chromosomes.
a. Things that occur to ensure genetic diversity (that’s why you
can have the same parents are your siblings, but still look
different even though your DNA comes from the same place.
i. Crossing Over of Chromosomes: see Diagram
ii. Segregation of Alleles: Alleles separate and move into different haploid gamete sex cell.
iii. Independent Assortment: Traits don’t follow each other, they move independently.
DNA Structure: DNA holds the genetic blueprint for all living organisms
1. DNA is found in the nucleus of all eukaryotic cells; it’s just floating inside of prokaryotic cells.
2. DNA is a form of Nucleic Acids (which is one of your 4 biomolecules‐ Lipids, Carbohydrate, Protein, Nucleic Acid).
a. Monomers: Nucleotides
b. Polymers: DNA and RNA
3. DNA is found in the form of a double helix. There are two strands that run anti‐parallel.
a. Backbone/Sides of DNA are made up of a sugar [Deoxyribose] and a phosphate
b. The steps/rungs of DNA are made up of paired bases
i. Adenine – Thymine
ii. Cytosine – Guanine
4. DNA is inheritable. You get your DNA, your genes, from your parents.
5. In the S Phase of the Cell Cycle, your DNA is replicated in preparation for mitosis, which is where one cell will
grow and divide into two cells.
Step 1: Step 2: Step 3: Step 4:
DNA double helix will The hydrogen bonds The enzyme DNA At the end, two DNA
unwind into ladder between the two Polymerase will add double helixes that are
form through the use base pairs will break. complementary identical to each other
of the enzyme Each strand of DNA nucleotides to the will be created. Each is
helicase. will serve as a original DNA template made up of ½ old and
template for the new to form a new strand ½ new DNA Strands.
DNA to be created. of DNA
