BIO 120 - SPRING 2010

The following information is provided to help you study for the second sectional exam.  Part A & B (terminology & concepts) represent "core" material that all Bio 120 instructors are expected to cover in their class.  The "standardized" portion of the final exam could contain questions about any of this material. Part C (classroom discussions, etc.) represents material that has been covered in class beyond the "core" material.  It is material that I will ask about on our sectional exam.  

A] Terminology:

• CHAPTER 7
• Mitosis - a process of cell division that produces two identical cells from an original parent cell (exact and complete duplication of the genetic instructions)
• Chromosome - hereditary structure in the nucleus of eukaryotic cells which is composed of DNA and protein
• Meiosis - a process of cell division that produces four cells that have half the number of chromosomes found in the original parent cell (these cells are not identical to each other, in terms of genetic information, and are not identical to the parent cell)
• Homologous chromosomes - pairs of chromosomes in normal cells that are usually the same size and shape and contain information about the same traits of an organism
• Fertilization - the fusion of the egg nucleus and the sperm nucleus
• Cancer - mass of abnormally dividing cells that can invade and colonize other parts of the body
• Metastasis - spread of cancer cells beyond their initial location
•  
• CHAPTER 8
• Genetics - the branch of biology dealing with the principles of heredity and variation in organisms
• Gene - refers to a specific genetic trait (e.g. flower color, seed shape, etc.)
• Allele - a particular form of a gene (e.g. the gene which controls flower color in roses may contain information which results in red roses or white roses - two different alleles for the same gene)
• Dominant allele - allele which shows its effect when present in a heterozygous pair
• Recessive allele - allele which does not show its effect when present in a heterozygous pair
• Homozygous alleles - pair of alleles for a single gene which contain the same genetic information
• Heterozygous alleles - pair of alleles for a single gene which contain different genetic information
• Genotype - an organism's allelic makeup (the total information stored in an organisms DNA, e.g. AA)
• Phenotype - the expressed traits of an organism (e.g. red roses)
• Incomplete dominance - pattern of inheritance where heterozygous individuals exhibit a phenotype that is in between the phenotypes of the homozygous individuals (e.g. red + white = pink)
• Codominance - pattern of inheritance where heterozygous individuals show full expression of both the phenotypes of the homozygous individuals (e.g. red + white = red & white striped)
• Pleitropy - pattern of inheritance where one gene has an impact on more than one trait
• Multiple alleles - having more than two possible alleles for a given trait
• Karotype - a picture or map of a cell's chromosomes arranged into their homologous pairs
• Autosomes - all the pairs of chromosomes of the cell that are not involved in sex determination
• Sex chromosomes - pair of chromosomes involved in sex determination
• Non-disjunction - a problem in meiosis where members of a chromosome pair fail to separate resulting in some daughter cells with one too many chromosomes and others with one too few chromosomes
• CHAPTER 9
• DNA - Deoxyribo Nucleic Acid
• DNA replication - Process by which a cell duplicates its DNA molecules before it divides into daughter cells
• Cloning - the process of making an identical genetic copy of an organism
• CHAPTER 10
• RNA - Ribo Nucleic Acid
• Transcription - the transfer of the genetic information from a DNA molecule to a RNA molecule
• Translation - the transfer of genetic information from the nucleotide code of RNA to the amino acid sequence of a protein molecule
• Codon - three nitrogenous bases that code for a particular amino acid
• Gene - portion of a DNA molecule that codes for a specific protein (note: molecular centered definition; defined differently above)
• Ribosome - a cellular structure in all types of cells where translation of genetic information from mRNA to protein occurs
• Genetic code - the amino acid translations of each of the codons

B] CONCEPTS

• CHAPTER 7
• Mitosis – Generalized overview of how it is accomplished with emphasis on:
  • Exact replication of the cell’s chromosomes (genetic information)
  • Daughter cells have the same genetic information as each other
  • Daughter cells have the same genetic information as the parent cell
  • Cytoplasmic division result in two cells from the original starting cell
  • This process is the basis of body growth, cell replacements, tissue repair, and asexual reproduction in eukaryotes
• Chromosomes
  • Composed of DNA and protein molecules
  • There is a constant chromosome number within an organism’s body cells
  • There is a constant chromosome number within a given species of organism
  • Most eukaryotic multicellular organisms have their chromosomes occurring in pairs (homologous chromosomes) in their body cells
• Meiosis - Generalized overview of how it is accomplished with emphasis on:
  • This process is the basis of gamete (sperm & egg) formation in sexual reproduction
  • Daughter cells have half the normal number of chromosomes
  • Daughter cells have one of each type of chromosome (no homologous pairs)
  • Daughter cells can be different from each other (in terms of the genetic information they hold) and different from the parent cell
  • Entails two division events and results in 4 cells from the original starting cell
• Fertilization –return to the normal number of chromosomes and homologous pairs of chromosomes (one set from each parent)
  • leads to an increase in variation in organisms
• Cancer
  • Results when cells lose control over their replication cycle, getting stuck in mitosis
  • Tumor formation – benign vs. malignant
  • 4 characteristics
    • cells grow and divide abnormally
    • the cytoskeleton and plasma membrane of cells are badly altered
    • the cells have a weakened capacity for adhesion (leads to metastasis)
    • the cells have lethal effects
   
• CHAPTER 8
• Gregor Mendel’s contribution to genetics
• Monohybrid cross - Punnett square or probability to determine results of cross
• Dihybrid cross and independent assortment of alleles
• What a human karyotype looks like (46 total chromosomes; 22 homologous pairs of autosomes & 1 pair of sex chromosomes)
• Sex chromosomes (XY = male in humans) (XX = female in humans)
• Other patterns of inheritance  
  • Incomplete dominance
  • Codominance (e.g. AB blood type)
  • Multiple alleles (e.g. ABO blood groups)
  • Pleitropy (e.g. multiple effects caused by mutation in DNA causing sickle-cell anemia or cystic fibrosis)
  • Several genes sometimes control a single phenotypic trait (e.g. height & eye color)
• The environment can affect how genes are expressed – the phenotype is the result of both genetics and the environment
• Continuous variation in traits of organisms usually shows a “bell curve” result
• X-linked recessive inheritance (e.g. color blindness & hemophilia)
• Nondisjunction – a problem caused by pairs of chromosomes which do not separate during cell division (e.g. Down syndrome)
• CHAPTER 9
• The discovery of DNA as the genetic molecule
  • The experiment with mice performed by Frederick Griffith (be able to describe)
  • The proof of DNA as the molecule involved with transforming nonvirulent bacteria (non-disease causing) to virulent form (disease causing) by Oswald Avery (how did he do this?)
  • James Watson and Francis Crick discover the double helix structure of DNA and provide the mechanism for DNA exact replication and an explanation of its role as the hereditary molecule
• Structure of DNA  
  • Double helix
  • Base pairing (A-T; C-G)
  • Four nucleotides of DNA: Adenine, Thymine, Guanine, Cytosine
• Replication – DNA able to make an exact copy by having the two strands separate, each serving as the template for a new strand.  Exact copying results due to the complimentary base pairing
• Cloning
  • Artificial twinning vs. nuclear transfer
•  
• CHAPTER 10
• Structure of RNA - single helix; ACGU nucleotides; similarities and differences to DNA
• DNA provides instructions on how to make protein molecules (carbohydrates and lipids produced by an organism are indirectly produced as a result of the action of protein molecules)
• Gene Expression – two steps needed to convert a gene into a protein  
  • Transcription – begins in nucleus when RNA strand copies the genetic information in the DNA molecule; the RNA can move from the nucleus into the cytoplasm and to the ribosomes
  • Translation – involves RNA at the ribosomes where the information is translated from the nucleic acid sequence (language) of RNA to the amino acid sequence (language) of protein
  • Special sequences of nucleotides on the DNA provides signals for the “start” of a gene and the “stop” point for RNA copying
• Translation is accomplished by translating a sequence of 3 nucleotide bases in RNA (a codon) to a particular amino acid (the building blocks of proteins)
• Mutations and their relation to protein synthesis
  • Base-pair substitutions
  • Frame shift mutations caused by deletions or insertions (more dangerous - be able to explain why)
• Cells in a multicellular organism are able to control their genes – this allows cell differentiation

C] ITEMS FROM CLASSROOM DISCUSSIONS, ETC.

• Difference in the division of cytoplasm between egg cells and sperm cells (be able to draw examples)
• Zygote - a fertilized egg cell
• How chemotherapy and radiation therapy works against cancer
• Be able to figure out the possible genotypes of eggs or sperm when looking at 2 genes (e.g. an AABb individual could produce AB or Ab sperm or eggs)
• Down syndrome's relationship with the age of the mother (be able to describe)
• Nondisjunction of sex chromosomes: XXX female; XXY Kleinfelter's syndrome; X_ Turner syndrome; Y_ = nonviable (embryo cannot develop without an X)
• Nondisjunction is usually (but not always) associated with a problem in the egg, not the sperm
• Why the 1962 Nobel Prize went to Maurice Wilkens, James Watson & Francis Crick for their discovery of the structure of DNA, but not to Rosalind Franklin.  And why it took till 1962 for these researchers to get a Nobel prize when they published their research in 1953.
• Undifferentiated cells vs. differentiated cells - what happens when these two types of cells divide by mitosis?
• How are identical twins formed?
• Embryo twinning - the natural or forced splitting of an early embryo which results in two genetically identical embryos
• Nuclear transfer - the replacement of an unfertilized egg nucleus with the nucleus of a differentiated cell (the way that adult cloning is accomplished)
• What is the disadvantage of embryo twinning to produce genetic clones?
• What is the advantage of using nuclear transfer to clone an adult organism?
• What was the first mammal that was successfully cloned from an adult?
• What are the major problems with cloning an adult organism through nuclear transfer?
• Be able to give at least three examples of animals that have been successfully cloned from adults.
• Reproductive cloning - cloning to produce a baby that is an identical twin of an adult organism
• Therapeutic cloning - cloning to produce cells, tissues, or organs for transplantation that are a genetic match to a sick person
• Embryonic stem cells - undifferentiated early embryo cells that can become any of the types of cells of the adult body
• Adult stem cells - partially differentiated cells in the adult body that have a limited capability to become several different types of cells in the adult body