Download Study Guide for Exam # 3 - HCC Learning Web

Houston Community College – BIOLOGY I
Instructor: Evel yn I. Milian
BIOL 1406: Study Guide for Exam # 3 – Chapters 11, 12, 13, 14 and 15
* NOTE: This is just a guide. It is not a comprehensive list of what may be on the test.
* Studying tips: For every test, including lab tests and the final exam, you should start studying early. If you start
studying one or two days before a test, you will feel overwhelmed and you will be under too much stress. Study every day
using your textbook, class notes and any other resources available. *** Study the figures and tables discussed in class as
well as those that have not been discussed in detail as they might help you understand the concepts. Study with a friend and
quiz each other. It is essential for you to be able to recognize, understand and apply the concepts, and use the scientific
vocabulary learned in class.
CHAPTER 11: Cell Communication
1. Understand the importance of communication between the cells of an organism.
2. Local and long distance signaling: know the types of cell communication:
a) Direct contact: cell junctions, cell-cell recognition
b) Indirect contact through messenger molecules: paracrine signaling (local regulators), synaptic
signaling (neurotransmitters), endocrine signaling (hormones)
3. Understand the three stages of cell signaling: reception, transduction, and response.
4. Three major types of plasma membrane receptors (you do not need to know how they work): G-proteincoupled receptors, receptor tyrosine kinases, and ion channel receptors
5. Know what is phosphorylation and dephosphorylation as part of transduction, and the enzymes involved
in each process: protein kinases and protein phosphatases
6. Know the second messengers in transduction: cAMP (cyclic AMP) and calcium ions (Ca2+). You do not
need to know how they work.
7. Remember that cellular responses can occur in the cytoplasm or in the nucleus.
CHAPTER 12: The Cell Cycle
1. Understand the basic terms discussed in class. You do not need to provide the textbook definition word
by word, but be able to understand and apply their meaning in the context of the topics and figures: cell
division, cell cycle, gene, genome, chromosome, chromatin, etc.
2. Chromosome structure: the organization and parts of a chromosome.
3. Know and understand the major stages of the eukaryotic cell cycle: interphase and mitotic (M) phase.
a) Interphase: understand its three subphases in the correct order; what happens in each one: G1
phase; S phase; G2 phase.
b) Mitotic (M) phase: understand its subphases in the correct order; what happens in each one:
mitosis and cytokinesis.
1) Mitosis: Overall, what is mitosis? You will need to be able to provide a complete definition
or description in a logical sentence. Know and understand the five phases of mitosis and the
major general events that happen in each one: prophase, prometaphase (late prophase),
metaphase, anaphase, and telophase. Remember that prometaphase is an intermediate
phase between prophase and metaphase (and that is why some books omit it).
 *** Study the figures discussed in class and in your book. You will need to be able to
identify the stages in figures, micrographs, or descriptions. As a guide, use the summary
of the stages of mitosis provided in my PowerPoint slides. Again, understanding the
basic terms related to mitosis is extremely important to understand the whole process:
mitotic spindle, centrosome, centromere, kinetochore, metaphase plate, etc.
2) Cytokinesis: What is it? How does it differ in animal versus plant cells?
4. Prokaryotic cell division: What is binary fission?
5. Regulation of the eukaryotic cell cycle: Understand briefly why and how the cell cycle is controlled.
a) Key regulatory molecules in the control of the cell cycle.
b) Three checkpoints in the cell cycle.
c) Apoptosis
6. Cancer: What is cancer; characteristics of cancer cells; carcinogenesis.
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Houston Community College – BIOLOGY I
Instructor: Evel yn I. Milian
BIOL 1406: Study Guide for Exam # 3 – Chapters 11, 12, 13, 14 and 15
CHAPTER 13: Meiosis and Sexual Life Cycles
1. Understand the basic terms discussed in class. You do not need to provide the textbook definition word
by word, but be able to understand their meaning: gene, locus, haploid, diploid, gametes, etc.
2. Asexual versus sexual reproduction: Understand them.
3. Sets of chromosomes in human cells: How many chromosomes are found in normal human somatic cells?
How many are derived from each parent?
4. Overall, what is meiosis? You will need to be able to provide a complete definition or description. Also
remember the following:
 Meiosis requires two cell divisions: Meiosis I and Meiosis II and results in four haploid
daughter cells with half the chromosome number of the parent cell.
 Meiosis is a “reduction division”; it reduces the number of chromosome from diploid to haploid,
ensuring that the number of chromosomes in offspring remains constant generation to generation.
 Understand what happens on a broad scale in meiosis I and meiosis II. You also need to
understand the major events that happen in each phase of meiosis.
 Meiosis I: prophase I, metaphase I, anaphase I, telophase I, and cytokinesis.
 Meiosis II: prophase II, metaphase II, anaphase II, telophase II, and cytokinesis.
5. Understand the main differences between meiosis and mitosis. ***Study the figures and tables,
especially the following in my PowerPoint slides: Figures 13.9 & 12.17, Tables 11-1, 10.1 and 10.2.
 Several events are unique in meiosis: synapsis and crossing over in prophase I; paired
homologous chromosomes (tetrads) in metaphase I; separation of homologues in anaphase I.
 In addition, the results for meiosis and mitosis are different; understand the results.
 Keep in mind that meiosis II is very similar to mitosis.
6. Genetic variation: Remember the events of sexual reproduction that contribute to genetic variation in a
population: independent assortment of chromosomes, crossing over, and random fertilization.
7. Life cycle of humans: Understand the significance of meiosis and mitosis in the life cycle of humans.
CHAPTER 14: Mendel and the Gene Idea
1. Terms: Understand very well the meaning of all the genetic terms discussed in class (such as: gene,
haploid, diploid, allele, locus, homozygous, heterozygous, genotype, phenotype, dominant, recessive,
etc.). It is essential for you to understand these terms, not just memorize their definitions, especially to be
able to apply them to situations and solve genetics problems.
2. Mendel’s model of inheritance:
a) Who was Gregor Mendel and what was his contribution to genetics? Have a general idea of his
experiments, results and phenotypic ratios, as well as the conclusions he made. * The figures in
your book and my presentation slides will help.
b) Understand very well his model of inheritance, including his laws or principles of heredity.
 Mendel’s law of segregation
 Mendel’s law of independent assortment
 Understand how Mendel’s laws are observed in meiosis.
3. Understand monohybrid versus dihybrid crosses.
4. Know and understand the steps to solve one-trait and two-trait genetics problems. *** This includes:
deciding on the allele key according to the dominant trait and the recessive trait (uppercase vs. lowercase
letter), determining the genotype of the parents (including if it is homozygous or heterozygous), possible
gametes that each parent can produce, using the Punnett square to find out the possible genotypes and
phenotypes of the offspring, and interpreting the results, as practiced in class.
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Houston Community College – BIOLOGY I
Instructor: Evel yn I. Milian
BIOL 1406: Study Guide for Exam # 3 – Chapters 11, 12, 13, 14 and 15
Beyond Mendelian Genetics:
5. Complete dominance; remember that the F1 offspring of Mendel’s classic pea crosses are an example of
complete dominance. The F1 plants always looked like one of the two parental varieties because of the
complete dominance of one allele over another.
6. Remember that inheritance patterns are often more complex than predicted by simple Mendelian genetics.
Alleles can show different degrees of dominance and recessiveness in relation to each other. In addition,
some of these patterns involve a single gene; others involve two or more genes. You should be able to
understand and recognize the following inheritance patterns in an example or situation (such as a cross).
a) Incomplete dominance. Remember the example discussed in class of the cross between a redflowered plant and a white-flowered plant, producing pink-flowered offspring.
b) Codominance & Multiple Alleles. Example: ABO blood types. Be able to solve a problem.
c) Pleiotropy. Example: sickle cell anemia.
d) Epistasis. Example: the coat color of mice.
e) Polygenic inheritance. Examples: human height, eye color, skin color.
7. Environmental impact on phenotype: Understand that the environment also plays a role in determining
traits. The expression of a phenotype for a character depends on environmental factors as well as on
genotype. Review the examples discussed in class (effect of temperature on plants and animals, etc.).
8. Pedigree: What is it? It is especially important to remember that a pedigree is useful to study the
patterns of inheritance of genetic disorders. You need to understand how to interpret a pedigree.
9. Understand the meaning of dominantly inherited disorder and recessively inherited disorder.
CHAPTER 15: The Chromosomal Basis of Inheritance
1. What is the chromosome theory of inheritance? * Understand the behavior of chromosomes in meiosis,
according to the law of segregation and the law of independent assortment.
2. Understand the inheritance of sex-linked (X-linked) genes. * Study the relevant figures.
 Understand the X-Y system for sex determination in humans and other mammals.
3. Linked genes: Understand what linked and unlinked genes are. Understand the relationship between
genetic recombination and linkage; the effects of crossing-over on the gametes and phenotypes.
4. Alterations of chromosome number or structure: Understand well the following alterations:
a) Changes in chromosome number – aneuploidy: Remember what it is and that it can be
expressed for example as monosomy or trisomy. Also, remember nondisjunction and the
example of Down syndrome (trisomy 21).
b) Alterations of chromosome structure: deletion, duplication, inversion, translocation.
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