Midterm 3 Study Guide
Midterm 3 Study Guide BIO 120 35
Popular in General Biology I
Popular in Biology
This 8 page Study Guide was uploaded by Kennedy Neil on Sunday November 22, 2015. The Study Guide belongs to BIO 120 35 at Grand Valley State University taught by Dr. Jennifer Winther in Fall 2015. Since its upload, it has received 153 views. For similar materials see General Biology I in Biology at Grand Valley State University.
Reviews for Midterm 3 Study Guide
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 11/22/15
B10 120 Midterm 3 Review 33 MultipleChoice Questions 15 points each Chapter 12 Explain why cells undergo mitosis Which cells undergo mitosis Mitosis is required for growth and development Gives rise to genetically identical daughter cells Somatic cells undergo mitosis every cell in the body EXCEPT reproductive cells sperm and egg What is a centromere and why it is important Def n the origin of the microtubules Why are they important Without centromeres the microtubules would not have a place to anchor themselves Therefore they would not be able pull the chromosomes apart during anaphase Describe the three phases of interphase 1 G1 Cells are just hangingout and doing their job in the organism 2 S synthesis Chromosomes are duplicated 3 G2 The cell checks to make sure no mistakes were made and makes repairs Describe in detail the 5 phases of mitosis See pages 236 and 237 in the textbook for more information 1 Prophase Centrosomes begin to moves to opposite sides of the cell Chromosomes begin to condense 2 Prometaphase Chromosomes are completely condensed No nuclear membrane Mitotic spindle centromere and microtubules is attached to kinetochores of a chromosome 3 Metaphase All of the chromosomes line up in the middle of the cell M is for Middle Sister chromatids are facing opposite centromeres 4 Anaphase Splitting apart sister chromatids A is for Apart 5 Telophase Reformed nuclear membrane Chromosomes begin to unwind Describe cytokinesis in animals and plants Provide an example of a cell type that undergoes mitosis without cytokinesis how could you tell by looking at the cell under a microscope that mitosis has occurred without cell division Def n The cytoplasm of the parent cell is divided into two daughter cells the two daughter cells start off small and then grow When cytokinesis doesn t occur mitosis results in cells with more than one nucleus like muscle cells Not part of mitosis This can be advantageous because it allows for better cellular communication Plants Animals No cleavage furrow A contractile ring is used to produce a Requires the formation of a cell wall cleavage furrow and split the cell in two and plasma membrane Follow a cell with 2n6 through interphase mitosis and cytokinesis keeping track of the number of chromosomes and chromatids Interphase 6 chromosomes 0 chromatids ProphasePrometaphase 6 chromosomes 12 chromatids Metaphase 6 chromosomes 12 chromatids Anaphase 12 chromosomes 0 chromatids Telophase 6 chromosomes 0 chromatids What is binary ssion Def n the way bacteria cells divide Not part of mitosis What are the different checkpoints during the cell cycle and why are they important There are checkpoints during the G1 and at the end of the G2 phases of interphase there is also one at the end of mitosis before cytokinesis They are important because they check for abnormalities in the DNA sequences and correct them Explain how cancer is related to the cell cycle and mitosis In cancer cells the checkpoints that normally occur during the cell cycle are either bypassed or just don t work Thus allowing abnormal bad cells to replicate Chapter 13 Explain why meiosis is important and which cells undergo meiosis Meiosis is required for sexual reproduction in eukaryotes Gives rise to genetically unique daughter cells It only occurs in the germ cells Describe in detail the ve phases in both meiosis I and meiosis II Meiosis I 1 Prophase I Homologous the same kind chromosomes pair up and create a bivalent aka synaptonemal complex 2 Metaphase I Homologous pairs of chromosomes in the bivalent structure align in the middle M is for Middle Crossing over occurs part of the homologous chromosome swap with the other 3 Anaphase I Homologous chromosomes attached in bivalent structure separate A is for Apart Sister chromatids remain homologous and move towards opposite centromeres 4 Telophase I and Cytokinesis The two new daughter cells have half of the chromosomes are the parent cell Meiosis 11 Whole point is to separate the sister chromatids Basically the same as meiosis I l Prophase ll 2 Metaphase ll 3 Anaphase ll 4 Telophase II and Cytokinesis What is similar and potentially different in homologous chromosomes Homologous chromosomes are pairs of chromosomes that have genes that code for the same thing on them For example say chromosome 1 has genes that code for hair color Both chromosomes in the pair of homologous chromosomes have genes that code for hair color But one of them may have the gene for blonde hair and one might have the gene for brown hair What is similar and different between mitosis and meiosis Mitosis Similarities Meiosis Only occurs in Interphase Has two stages somatic cells all body 0 Both occur after G2 meiosis I amp ll C6115 except for germ Both use the mitotic Only occurs in germ cells spindle to separate cells Sperm amp egg Yields two genetically chromosomes Yields four identical cells 0 Cytokinesis usually genetically unique follows 66115 Explain how when during meiosis genetic variation is generated during meiosis In order for meiosis to result in genetically unique daughter cells crossing over must occur The point of crossing over between homologous chromosomes is called the chiasmata Crossing over allows the homologous chromosomes to swap sections of their genetic material Chapter 14 What does it mean for a trait to be dominant How does one determine if a trait is dominant If a trait is dominant it means that if it is paired with a recessive the opposite of dominant allele the phenotype will be that of the dominant allele You van determine if a trait is dominant by examining a pedigree What does it mean for an organism being true breeding If an organism is true breeding it is homozygous What are the assumptions of simple Mendelian inheritance l Homozygous parents 2 Sex of the parent doesn t matter what genes come from which parent Basically not a sexlinked gene 3 Mendelian segregation of alleles 4 Independent assortment of alleles No linkage 5 Equal survival of gametes A certain gene combination cannot be lethal 6 Random fertilization 7 Equal survival of all progeny 8 Suf ciently large number Describe when you would use the addition rule and when you would use the multiplication rule Addition rule probability of event A or event B happening Multiplication rule probability of event A and event B happening Explain the follow inheritance patterns and how the results in the F1 andor F2 generation vary from simple inheritance patterns incomplete dominance codominance multiple alleles epistasis polygenic Incomplete dominance Def n Phenotype of heterozygote is intermediate between those of the homozygous based on some quantitative measure Basically when you have a heterozygote you don t get the dominant phenotype You get the mix between the dominant and recessive phenotypes RRred rrwhite Rrpink F2 l2l Codominance Def n The expression of both alleles of a heterozygote RRred rrwhite Rr red and white spots Multiple Alleles Def n Many alleles are present in a population for a given gene each individual has only two of the alleles Epistasis Gene interactions expression of a gene at one locus alters the expression of another gene at another locus Polygenic Have quantitative characters there s a continuum not an either or circumstance Ex height Describe the pedigree patterns one would expect to see in an autosomal dominant trait and an autosomal recessive trait Autosomal dominant Males and females equally affected Affected phenotype occurs in each generation Affected males and females give rise to affected progeny Affected individuals are usually heterozygous Autosomal recessive All affected individuals are homozygous aa Tends to skip generations Chapter 15 Describe how the X and Y chromosome in humans are different and similar and how sex is determined in humans Sex chromosomes determine whether someone is male or female In males the Y chromosome codes for the SRY gene that cause testes to form instead of the default ovaries In humans the X chromosome codes for over 1000 genes and the Y chromosome codes for 80 genes Describe Xinactivation Explain calico coloring in cats Female mammals inherit 2 X chromosomes but only one of them is active is any one Cell the inactive X chromosome is called a Barr body But it doesn t have to be the same X chromosome that is active in every cell In some cells the X from the father could be expressed and in other the X from the mother could be expressed For example in cats males can have either a black XB Y or orange coat Xb Y And females can have black XB XB orange Xb Xb or calico XB Xb coats So in a calico cat the different colors come from the varying expression of the X chromosome What is linkage and how does it impact predicted phenotypes Explain why linkage is important Def n Linked genes are genes located near each other on the same chromosome and for the most part are going to be inherited together Causes the expected phenotypes to be different because of the lack of independent assortment Linkage is important because it helps us to understand complex inheritance patterns as well as determine the location of genes on chromosomes Describe nondisjunction and how it results in aneuploidy Aneuploidy Def n When there is an abnormal number of a particular chromosome Nondisjunction Def n When chromosomes fail to slit apart during anaphase can happen during meiosis I or II Ex Down Syndrome Describe polyploidy Defn When there is more than the normal number of all of the chromosomes Usually results in a normal phenotype because the ratios are the same Describe 3 alterations that can occur to chromosome structure and their potential impacts on reproduction l Deletions a portion of genetic code is deleted 2 Duplications a portion of genetic material is duplicated 3 Translocations a portion of genetic material is moved to another area on a chromosome causes infertility 4 Chapter 16 Describe the structure of DNA including 3 and 5 strand how bases pair DNA is composed of two strands of nucleotides twisted into a double helix Backbone of the two strands is antiparallel opposite in orientation 5 end ends in phosphate 3 end ends in hydroxyl AT two hydrogen bonds CG three hydrogen bonds Explain how DNA is replicated Include the important enzymes steps and difference between leading and lagging strands Explain how it starts elongates and ends Semiconservative replication the strands separate and then each acts a template for a new DNA strand to be formed this minimizes mutations Occurs during the S phase of interphase 1 Proteins attach to the origin sites on DNA 2 Helicase breaks the hydrogen bonds and separates the two strands of DNA creating a replication bubble 3 Each end of the bubble has a replication fork where the parental strand continues to unwind 4 The unwound areas then serve as templates for the synthesis of new DNA Single stranded binding proteins keep the separate DNA apart Topoisomerase relieves the strand of DNA that is coiled ahead of the replication fork Basically it prevents the DNA from becoming tangled before it is unzipped by Helicase Primase makes a small RNA molecule primer complementary to the DNA that is required to start replication DNA polymerase catalyzes the synthesis of new DNA by adding complementary nucleotide it knows which base is to add because of the number of hydrogen bonds as well as the size of the nucleotide DNA polymerase I removes the RNA primer and adds in a new piece of DNA resulting in Okazaki fragments DNA polymerase III moves away from the replication fork Ligase binds the Okazaki fragments together
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'