C9. If an abnormal repressor protein could still bind allolactose, but
the binding of allolactose did not alter the conformation of the
repressor protein, how would this affect the expression of the lac
It would be impossible to turn the lac opero
C1. In the case of multicellular animals, what are the four types of
cellular processes that occur so a fertilized egg can develop into an
adult organism? Briefly discuss the role of each process. The four processes are cell division,
Trisomy of chromosome 21
Which form of NDJ is more viable? Which is mostly lethal?
Sex Chromosome: viable (DOSAGE COMPENSATION)
Trisomy? Monosomy? Triploid? Polyploidy?
Trisomy- three copies of c
Chromosome, Centromere, Chromatid?
Usually 2 chromatids, one molecule of DNA each
Centromere holds together
What happens in each part of interphase? How many chromosomes/chromatids?
G1: 46 chromosomes, 46 chromatids
S: 46 chromosomes, 92 ch
What are the three types of genetics?
1. Classical/Transmission (passage of genes)
2. Molecular (DNA, coding, replication, transcription, etc)
3. Population Genetics (change over time)
tiny mature adult inside the sperm (homunculus)
type of single base substitution (point mutations); when a purine is substituted for a
pyrimidine or a pyrimidine replaces a purine
One or more nucleotides is deleted or inserted in the DNA.
when a purine
X2 = Sum (O-E)^2/E
-heterozygote has a phenotype intermediate to the homozygotes
-1:2:1 phenotypic ratio
rr = White
Rr = Pink
-Heterozygote expresses both alleles
1. 15N was used as a medium to grow bacteria with intermediate density to be used in replication with
14N bacteria in order to determine whether DNA uses a conservative, dispersive, or semi-conservative
2. The 3-OH group is
a. The first experiment conducted by Griffiths, in 1928, used two strains of the pneumonia
bacteria each injected into live mice. The 3S strain was found to kill the mouse, while the 2R
strain was found to be fought off by the mouses immun
a. Amino Acid: Glu Trp Asp Ser His Met His STOP
b. DNA Template Strand: 3-CTC ACC CTG AGG GTG TAC GTA ACT-5
2. Repeating UUAC mRNA strand: UUA CUU ACU UAC
Resulting Amino Acids from repeating UUAC mRNA: Leu Leu Thr Tyr
Repeating UAUC mRN
b. Ampicillin-sensitive, tetracycline resistant
Primers, Magnesium concentration, dNTP concentrations, and cycling temperatures.
3. ddNTPs are structurally different from dNTPs because the 3 OH group is replaced by a si
1. No colonies are expected to grow due to lack of sufficient nutrients/supplements.
Transformation: Bacteria can take in environmental DNA, which is sometimes integrated into
their own bacterial genome, transforming it.
1. The Genes are located on different places between the two chromosomes.
2. Meiosis produces haploid gametes that are different genetically due to the two processes of
independent assortment and crossing over, shuffling alleles around duri
1. Mutations are essential to the evolutionary process because they can lead to variation, allowing for a
change in natural selection of a species.
2. Random mutation is more likely to be deleterious due to the intricate design of DNA, where
Hfr cell (high-frequency recombination)
donor cells with F factor integrated into the donor bacterial chromosome.
F prime cells (F' cells)
contains F plasmid carrying some bacterial genes
partial diploid bacterial cells containing F'
Complimentary Gene Action
two genes compliment each other
-can only produce 1 gamete (human female-x)
can produce different gametes ( human male, X or Y)
Environmental Sex determination
-temp of org's development deter
Autosomal Recessive Trait
tends to skip generations
no difference in expression between genders
mating between expressing individuals should produce 100% expressing offspring
expression incidence increases with consanguineous marriages
C1. Discuss three important advances that have resulted from gene
First, cloned genes can be used for DNA sequencing. This has allowed
researchers to understand genetics at the molecular level. Second, cloned genes can be
mutated using site-direc
Chapter 16 questions
C1. What is the difference between a constitutive gene and a regulated
gene? A constitutive gene is unregulated, which means that its expression level
is relatively constant. In contrast, the expression of a regulated gene varies unde
C5. An operon is repressiblea small effector molecule turns off
transcription. Which combinations of small effector molecules and
regulatory proteins could be involved?
A. An inducer plus a repressor
B. A corepressor plus a repressor
C. An inhibitor plus
C1. For each of the following mutations, is it a transition, transversion,
addition, or deletion? The original DNA strand is
(Note: Only the coding DNA strand is shown.)
C1. Discuss the common points of control in eukaryotic gene
1. DNAchromatin structure. This includes gene amplification, an increase in
number; gene rearrangement, as in immunoglobulin genes; DNA methylation, attachment
of methyl groups,
C12. Would a mutation that inactivated the lac repressor and prevented
it from binding to the lac operator site result in the constitutive
expression of the lac operon under all conditions? Explain. What
is the disadvantage to the bacterium of having a co
*C15. As described in Chapter 15 , enzymes known as aminoacyl-tRNA
synthetases are responsible for attaching amino acids to tRNAs.
Let's suppose that tryptophanyl-tRNA synthetase was partially
defective at attaching tryptophan to tRNA; its activity was on
*C18. Translational control is usually aimed at preventing the initiation
of translation. With regard to cellular efficiency, why do you think
this is the case?
It takes a lot of cellular energy to translate mRNA into a protein. A cell
wastes less energy
wilkins and frankling
took xray diffraction pictures used in constructing the structure of DNA
determined that DNA contains Nitrogenous bases
Hershey & Chase
identified DNA as the genetic material in baccteriophage
-differential x-inactivation (different from cell to cell)
-tortoise shell phenotype of cat coat
-can be in males but has to be XXY, etc.
-difference in dominance between male vs. females
ex: bearded goa
A diagram of a family tree showing the occurrence of heritable characters in
parents and offspring over multiple generations.
in genetics research, the individual displaying the trait or characteristic being
Non-linked genes (recombination)
-all 4 gametes occur
Parental types? Recombinant?
parental: no crossing over
recombinant: crossing over, RARE EVENT
What do all of these people have in common?
Important steps leading to the discovery of the
structure of DNA
1. Particulate nature of heredity, genes- Gregor
2. One-gene-one protein hypothesis: Beadle and
Tatum (what gives us our phenotypes)