Review Sheet for Exam #3 (Morris Chapters 9 - 12)
Dr. Solti
This review is meant to serve as a guide to ensure your notes are complete. You will need to be able to
do/understand and READ YOUR BOOK! Simply filling out this review sheet will not be enough to earn a good
grade.
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4 essential elements of communication
4 key steps in cell signaling
4 types of cell signaling
terms "ligand" and "ligand-binding site"
Cell surface receptor: G-protein coupled (adrenaline signaling in heart muscle), receptor kinase (kinase adds a
Pi; phosphatase removes a Pi; mutations called kit), ligand-gated ion channel (between neurons and neuron and
muscle cells)
Cell-signaling and cancer
Know the figure on The Human Life Cycle
Bacteria reproduce by binary fission (mitosis)
Know the comparison between prokaryote and eukaryote genome
Mitosis is a reproducing division (copying) that leads to division of one cell into 2 daughter cells, each with the
genetically identical 46 chromosomes. Used to make somatic cells. Have no homologues, no synapsis, no
tetrads, no crossing over.
Mitosis: division of the nucleus and the chromosomes
Cytokinesis: division of the cytoplasm and cell
o In animals: occurs by cleavage furrow
o In plants: occurs as cell plate
Know the definitions of : gene, chromatin, chromosomes, centromere, somatic cell, gamete, haploid, diploid,
fertilization
Know the figure on The Cell Cycle------one generation of a cell
o Mitotic phases- shortest part of cell cycle (only 10%)
 Mitosis (M)
 Cytokinesis ( C )
o Interphase phases– nondividing , growth and development (90% of cell cycle)
 G1 – growth 1
 S - DNA synthesis (this is where the sister chromatids are made): remember, “need to
multiply to divide”
 G2 – growth 2 and preparation for division
o Nerve and muscle cells stay permanently in G0 once they are developed
Know the Stages of Mitosis
o Prophase: longest phase of mitosis
 Condensation/shortening of sister chromatids: in nucleus
 Formation of mitotic spindle: in cytoplasm (comes from the centrosomes: which are the
microtubule-organizing centers)
o Prometaphase:
 Nuclear envelope disintegrates
 Kinetochore microtubules formed (puppets on a string)
o Metaphase:
 46 pairs of sister chromatids line up at metaphase plate
o Anaphase:
 Sister chromatids separate and go to opposite poles
o Telophase/C
 Nuclei are reformed
 Nucleoli are reformed
 Chromosomes become unobservable chromatin (chromosomes are only observable during
mitosis or meiosis)
 Cytokinesis occurs
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Review Sheet for Exam #3 (Morris Chapters 9 - 12)
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Dr. Solti
Centromere: where the sister chromatids attach to each other in S phase and detach in Anaphase. If you have
12 centromeres, how many chromsosomes will you have in each daughter cell? 12
Cytokinesis: cleavage furrow in animals by actin microfilaments; cell plate in plants by Golgi body vesicles
that turn into cellulose cell wall
Know the definitions for: heredity, variation, genetics, DNA, locus, asexual reproduction, somatic cell, gamete,
diploid, haploid, fertilization, zygote, karyotype, homologous chromosomes
Gamete: sex cell; either sperm or egg; they are haploid, only one set of 23 chromosomes
Somatic cells: all other body cells; always diploid; having 2 sets of homologous chromosomes (one set from
Mom, and one set from Dad)
Meiosis is a reduction division; goes from 1 diploid pre-gamete cell to 4 haploid gametes; occurs in
testes/ovaries to make sex cells; leads to genetic variability
Know the Stages of Meiotic Cell Division
o Meiosis I: to separate homologues and make haploid cells
 Prophase I: homologues find each other and line up side by side (synapsis) to form a
tetrad/bivalent; then they do crossing over of chromatids (chiasmata where they cross over);
leads to tremendous variation
 Metaphase I: 23 tetrads (23 pairs of homologues and their sisters) line up at metaphase plate;
tetrads do independent assortment for how they line up; leads to tremendous variation
 Anaphase I: tetrads split up (homologues separate)
 Telophase I/Cytokinesis: 2 haploid cells form, but still have sister chromatids attached
o Meiosis II: to separate the sister chromatids (identical to mitosis)
 Prophase II
 Metaphase II
 Anaphase II: separate sister chromatids
 Telophase II/Cytokinesis: now have 4 haploid cells, each with 23 chromosomes
If an organism’s liver cells have 500 chromosomes each, how many chromosomes will each sperm cell have?
250
Understand the comparison between Mitosis and Meiosis
Genetic variation in meiosis occurs during: Prophase I (crossing over), Metaphase I (independent assortment),
random fertilization
Female vs. male meiosis
DNA damage checkpoints
Cancer terminology & cancer
Multiple mutation model for cancer development
Review of DNA structure
Enzymes/Proteins of DNA replication
Semiconservative Model for replication
Replication occurs 5' to 3'
Leading strand vs. lagging strand
RNA primer
Proofreading
Telomeres and telomerase
PCR technique
Gel electrophoreisis
Restriction enzymes and fragments
Recombinant DNA and transformation
GMOs
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