Exam 4

Question 1

how is relative fitness (W) calculated?

Answer 1

Wx = (# of offspring of x) / (# of offspring of the one with the highest fitness)
gene with the highest reproductive value (most offspring) will always have a fitness of W = 1.0 and other fitness values will be determined relative to that one

Question 2

what is a population?

Answer 2

the term for a group of organisms of the same species that can interbreed and live in an isolated group

Question 3

monomorphic vs polymorphic vs monogenic vs polygenic

Answer 3

monomorphic: a gene that has only one allele
polymorphic: a gene with two or more alleles
monogenic: controlled by a single gene
polygenic: controlled by more than one gene

Question 4

what is directional selection and what is an example?

Answer 4

when the survival of one extreme phenotype or the other is favored, dark winged butterflies are favored in dark environments as opposed to light winged ones

Question 5

what is balancing selection and what is an example?

Answer 5

when the maintenance of two or more alleles are favored, heterozygotes with sickle cell anemia are more likely to survive when infected with malaria, or pollinators visiting more rare flower colors more which keeps one color from becoming too common or rare

Question 6

what is disruptive selection and what is an example?

Answer 6

when survival of two different phenotypes is favored, more than one snail shell color is preserved because different environments have different shell colors that are favored

Question 7

what is stabilizing selection and what is an example?

Answer 7

when survival of individuals with intermediate phenotypes is favored, laying a medium amount of eggs is favored as opposed to laying too many to take care of or too few to survive

Question 8

in the field of population genetics and evolutionary biology what does the term fitness refer to?

Answer 8

the ability to survive and reproduce

Question 9

what is the Hardy-Weinburg equation and what does each variable represent?

Answer 9

p^2 + 2pq + q^2 = 1
2pq: frequency of heterozygous individuals (Gg)
p^2: frequency of homozygous dominant individuals (GG)
q^2: frequency of homozygous recessive individuals (gg)
used to determine the expected frequencies of the genotypes in a population if they are not changing

Question 10

if a population is at Hardy-Weinburg equilibrium for a particular gene what does this mean?

Answer 10

the population is not evolving

Question 11

what is genetic drift?

Answer 11

random changes in allele frequency as a result of chance events, therefore is a small group of animals establishes a new population away from the original group then the new one is likely to be different from the original one

Question 12

what is gene flow?

Answer 12

when individuals migrate between populations with different allele frequencies, pollen from one flower being carried to a new population or animals mating with another population

Question 13

what is nonrandom/assortative mating?

Answer 13

when individuals choose to mate with those of a specific phenotype as opposed to choosing randomly

Question 14

what is the correlation coefficient and what is the value of its degrees of freedom?

Answer 14

correlation coefficient is the strength of the association between two variables, its degrees of freedom is n-2

Question 15

what is variance and what is the value of its degrees of freedom?

Answer 15

variance is the statistic to evaluate variation in a population, its degrees of freedom is n-1

Question 16

what is covariance and what is the value of its degrees of freedom?

Answer 16

covariance is the degree of variation between two variables within a group, its degree of freedom is n-1

Question 17

what are quantitative traits?

Answer 17

quantitative: study of traits that can be determined numerically and categorized as anatomical, physiological, behavioral, and human diseases

Question 18

what characteristics do quantitative traits usually have?

Answer 18

environmental influence, polygenic basis, and continuous distribution

Question 19

what is heritability and how do you interpret its value?

Answer 19

heritability is a measure of whether observed variation is due to genetics or the environment
a heritability value of 1 means all of the variation is due to genetics
a heritability value of 0 means all the variation is due to the environment

Question 20

how can you determine the total variance of a population for a quantitative trait?

Answer 20

sum the genetic and environmental variances

Question 21

what does quantitative trait loci mapping determine?

Answer 21

determines relationships between quantitative traits and molecular markers such as RFLPs

Question 22

what is a critical factor for preparing genomic DNA to make a library for genome sequencing?

Answer 22

partially digesting the DNA with a restriction enzyme

Question 23

which technique is needed when performing an RFLP analysis to test for a genetic disease?

Answer 23

southern blot

Question 24

why is Sanger sequencing no longer used for genome sequencing?

Answer 24

the products of a sequencing reaction need to be separated to determine the DNA sequence, it is relatively slow, and it is relatively expensive

Question 25

what is used as "probes" to study protein expression in a protein microarray?

Answer 25

antibodies

Question 26

how can you determine if genes are homologs?

Answer 26

if genes are orthologs (genes at the same locus) they will have the same number, if genes are paralogs (related genes within or between species) there will be a corresponding genes in the other species where it is blank for one species, orthologs and paralogs both count as homologous species

Question 27

what are different types of BLAST searches and what are they used for?

Answer 27

blastn: nucleotide vs nucleotide (used for DNA to DNA research) blastx: translated nucleotide vs protein database (used for DNA to cDNA research) blastp: protein vs protein database (used for amino acid to protein research)

Question 28

what is mapping?

Answer 28

the experimental process of determining the relative location of genes or other segments of DNA along individual chromosomes

Question 29

what is replacing microarrays as a powerful tool to study gene expression?

Answer 29

transcriptome sequencing

Question 30

what do chromatin immunoprecipitation (chIP) assays determine?

Answer 30

used to determine if proteins can bind to a particular region of DNA

Question 31

what does mass spectroscopy determine?

Answer 31

determines the amino acid sequence of a protein from a gel and then the amino acid sequence can be searched against a database to determine gene identity, also used to identify protein covalent modifications

Question 32

what is proteomics?

Answer 32

the study of the proteome (all of the proteins produced) and how they interact with each other

Question 33

in proteomics if you identify a protein that is differentially expressed between two samples by 2D electrophoresis, what technique could you use to determine the gene that it came from?

Answer 33

mass spectroscopy

Question 34

what animals do humans share 30%, 75%, 80%, and 98% of their genome with?

Answer 34

30%: yeast 75%: dogs 80%: mice 98%: chimpanzees

Question 35

how many genes do most eukaryote genomes usually contain?

Answer 35

~ 25,000

Question 36

the RNA level _______ the steady-state level of the corresponding protein, and the post-translational modification of the protein ________ from RNA data?

Answer 36

doesn't necessarily reflect, can't be determined

Question 37

what is metagenomics?

Answer 37

the study of the collective microbial genome in an environmental sample

Question 38

what is comparative genomics?

Answer 38

compares whole genomes of different organisms to answer questions about genetics and other aspects of biology (dogs being used as a model system for studying heritable genetic diseases in humans)

Question 39

in a disease that is due to a single genes, the concordance among monozygotic twins should be what?

Answer 39

100%

Question 40

what of the following best describes most cancers?

Answer 40

the statistical likelihood for developing many types of cancer is heritable

Question 41

what are proto-oncogenes and oncogenes?

Answer 41

proto-oncogenes: normal un-mutated version of oncogenes oncogenes: mutations in these genes promote cancer by keeping the cell growth signaling pathway permanently on, promoting unregulated cell division

Question 42

what are tumor suppressor genes?

Answer 42

genes that prevent the proliferation of cancer cells, mutations that inactivate these genes make it more likely than cancer will occur, regulate cell-cycle checkpoints and initiation of apoptosis

Question 43

what kind of mutation in oncogenes and tumor suppressor genes result in a gain or loss of function?

Answer 43

missense mutations because they can trade GDP for GTP on a protein which causes it to be activated and divide

Question 44

what do cyclins/cyclin-dependent kinase complexes control in normal cells?

Answer 44

the cell cycle

Question 45

what are metalloproteinases?

Answer 45

a class of genes that is up-regulated in the process of metastasis, present in high levels in malignant tumors

Question 46

what is the p53 gene and what class of gene is it?

Answer 46

a gene associated with 50% of all human cancers since its mutated form can no longer bind to DNA properly meaning it cannot activate p21 to act as a stop signal, allowing cells to divide uncontrollably, it is a tumor suppressor gene

Question 47

what are the steps of cell division that lead to the development of a tumor?

Answer 47

initial tumor cell starts to experience benign growth, then malignant growth starts to spread to the surrounding tissue, cells then become metastatic (moves to different area of the body) and enter the bloodstream, angiogenesis is the recruitment of blood vessels by a tumor

Question 48

what would a mutation that causes a loss of cell cycle regulation alone lead to?

Answer 48

a benign tumor

Question 49

under strictly controlled conditions, a short DNA probe will hybridize in vitro only its complementary sequence and not sequences that differ from it by even one nucleotide, this information is used in medicine to design ......

Answer 49

ASOs

Question 50

the first successful case of gene therapy involved transforming human cells with a "wild-type" (non-mutated) copy of a gene, for what kind of genetic disease can this approach be used?

Answer 50

a disease caused by genetically recessive mutation in an essential gene

Question 51

what is amniocentesis and chronic villus sampling?

Answer 51

amniocentesis: when fetal cells are obtained from the amniotic fluid and genetically tested CVS: cells are obtained from the placenta part of the fetus and genetically tested, can be performed earlier in the pregnancy than amniocentesis

Question 52

what is an advantage of ASO testing for prenatal diagnosis in contract to RFLP analysis?

Answer 52

ASO testing can be used for mutations that do not create or destroy a restriction site

Question 53

which method of post-transcriptional regulation of mRNA is utilized in some types of gene therapy?

Answer 53

RNA interference

Question 54

which of the following scenarios could RNAi be used to treat?

Answer 54

a disease caused by over-expression of a particular gene

Question 55

which component of a CRISPR array are responsible for determining the specific sequence of the DNA target that will be cleaved?

Answer 55

spacer regions

Question 56

how long have humans been using biotechnology?

Answer 56

>10,000 years

Question 57

what are the advantages of using recombinant DNA technology to produce insulin in bacteria rather than the previous methods?

Answer 57

the insulin produced has less side effects because it is "human" insulin, it is cheaper, and it is safer

Question 58

which organism is used by molecular biologists to introduce genes into plant genomes?

Answer 58

agrobacterium tumefaciens

Question 59

which gene widely used in genetically modified crops encodes a protein that is also widely used in organic agriculture?

Answer 59

cry from bacillus thuringiensis

Question 60

how do you determine the sequence of primers that could be used to amplify a DNA sequence by PCR?

Answer 60

(DNA sequence runs 5’ to 3’) first primer is the same as the first part of the sequence (5’ to 3’) second primer is the complementary strand running the opposite way as the template strand (primer runs 5’ to 3’ starting at the 3’ end of the template strand) question 51 on exam 2

Question 61

if a single DNA segment is transferred from one (non-homologous) chromosome to another by recombination, what has occurred?

Answer 61

a simple translocation

Question 62

which of the labeled structures are complexes of proteins and nucleotide polymers?

Answer 62

1 and 4 (question 4 on exam 1)

Question 63

what is the basic repeating structural unit of chromatin?

Answer 63

a nucleosome

Question 64

which of the following classes of RNA have catalytic activity?

Answer 64

rRNA

Question 65

in eukaryotic translation, once the stop codon UGA is reached, what triggers the release of the peptide and the disassembly of the ribosome?

Answer 65

binding of eRF1 to the A site of the ribosome

Question 66

which of the following is encoded by the mRNA COVID vaccines?

Answer 66

spike glycoprotein

Question 67

what feature engineered into plasmid cloning vectors allows you to visually select bacteria transformed with plasmids that contain DNA inserts from those with plasmids that do not?

Answer 67

lac Z

Question 68

a small effector molecule that increases the level of transcription is a called a/an?

Answer 68

inducer

Question 69

what does deamination of 5-methyl cytosine cause?

Answer 69

C to T mutations

Question 70

when studying a genetic cross, the second generation following the initial cross is identified by which of the following?

Answer 70

F2 generation

Question 71

the observable characteristics of an organism are called its _________?

Answer 71

phenotype

Question 72

hypothesis: two particular genes segregate independently. After investigation: experimental data v’s expected data gives a X^2 = 0.5 (1 degree of freedom). What can you conclude?

Answer 72

the genes likely segregate independently question 39 on exam 3

Question 73

the production of gene families, such as the globin genes, is the result of _________?

Answer 73

gene duplications