Exam 2 Flashcards
Biology 100 KU
The figure diagrams one of the genetic crosses that helped Mendel form his theories of inheritance. Which process distributes P alleles to approximately one half of the F1 gametes and the p allele to the other half?
a) independent assortment
b) mitosis
c) meiosis
d) chromosome crossover
C
In Labradors, coat color and blindness are each controlled by an independent locus. These loci show independent assortment. Based on your understanding of Mendel’s law of independent assortment, this suggests that these loci
a) are on homologous chromosome (linked).
b) are on separate chromosomes (unlinked).
c) showmultigenicinheritance.
d) are controlled entirely by environmental conditions.
B
Olivia’s parents, Mrs. Lisa Keller and Mr. Kevin Keller, are (A-) and (O+). You know about the IA/IB/i alleles for ABO blood type and the Rh D factor alleles, +/-. Olivia has O- blood. Using your Punnett Squares and the phenotypes of the three Kellers, indicate which of the following
is the most likely set of genotypes for Lisa and Kevin Keller.
Lisa Kevin
A. IA/i,-/- i / i, +/+
B. IA/IA,-/- i / i, +/-
C. IA/i,-/- i / i, +/-
D. IA/IA,-/- i / i, +/+
C
Looking at the Kellers and Morrisons, is it possible that Kevin Keller had an affair with Cynthia Morrison and is Diana Morrison’s biological father?
Lisa Keller(A-) + Kevin Keller(O+) = Olivia (O-)
Cynthia Morrison(B+) + Husband(O- ) = Diana(A+)
A. Yes, Cynthia and Kevin could have a child like Diana with Rh posiHve blood.
B. No, Cynthia and Kevin could not have a child who has type A blood.
C. No, Cynthia and Kevin could not have a child who was Rh posiHve.
B
Looking at the Kellers and Morrisons, is it possible that Kevin Keller had an affair with Cynthia Morrison and is Diana Morrison’s biological father?
Lisa Keller(A-) + Kevin Keller(O+) = Olivia (O-)
Cynthia Morrison(B+) + Husband(O- ) = Diana(A+)
A. Yes, Cynthia and Kevin could have a child like Diana with Rh posiHve blood.
B. No, Cynthia and Kevin could not have a child who has type A blood.
C. No, Cynthia and Kevin could not have a child who was Rh posiHve.
B
Autosomal inheritance
inheritance of traits with loci on chromosomes other than sex chromosomes
Autosomal Recessive: Punnett Square
HH; Hh; Hh; hh
Lisa Keller and her parents and sister have normal blood clotting, but she has a brother with hemophilia C (autosomal recessive). What is the probability that she is a carrier? A. 25% B. 50% C. 67% D. 100% E. More information is required.
C– 2/3 because she is not hh since she does not have it
Square on pedigree
Male
Circle on pedigree
Female
Filled in on pedigree
Shows trait
Dot on pedigree
Carrier
Which of the following pedigrees, show the inheritance pattern predicted from your rules for an autosomal recessive trait.
(Look to slides for pedigree)
C
Is the Y chromosome bigger or smaller than X?
Smaller
Any gene located on a sex chromosome is called
a sex-linked gene
Red-green colorblindness is
– a common human sex-linked disorder
– caused by a malfunction of light-sensitive cells in the eyes.
X-linked Recessive: Punnett Square
X^H X^H; X^H X^h; X^H Y; X^h Y
If instead of having Hemophilia C (autosomal recessive), Lisa Keller’s brother had Hemophilia A (X-linked recessive), what would be the probability that she was a carrier?
A. 25%
B. 50%
C. 67%
D. 100%
E. More informaHon is required to answer this question.
B
For the following pedigrees, indicate the inheritance paOern predicted from your rules for an X-linked recessive trait.
(Look to slide for Pedigree)
A
Remember that Lisa’s brother had hemophilia, but her sister and parents did not. It turns out that her mother’s sister died very young, apparently of a massive hemorrhage. Which of the following is an accurate pedigree of Lisa Keller’s family?
Look to slide for pedigree
A
Lisa Keller can opt for gene testing to determine if she is a carrier for hemophilia, but it is expensive, so she wants to use her family pedigree to inform her choice. Given this pedigree, which type of hemophilia can she rule out?
A. X-linked recessive Hemophilia A
B. Autosomal recessive Hemophilia C
C. Neither, not enough informaHon was given.
A
The genetic material at the molecular level has to account for three important properties of inheritance. The genetic material must
• be able to copy itself
• be able to direct the expression of an organism’s phenotype
• generate variation in some manner
Which of the following processes accounts for these properties? (Order: Copy, phenotype expression, variation)
A. Transcription, translation, replication
B. replication, translation, mutation
C. replication, transcription, mutation
D. translation, mutation, replication
B
Screen Shot 2016-10-15 at 12.59.53 AM
Mis-Sense (substitution) Mutation
Mis-Sense (substitution) Mutation
Changes one amino acid, but does not cut off short; changes on base which changes the amino acid, but not to a stop codon
Non-Sense Mutation (truncation)
Changes a base to cause a stop codon; shortens the protein; stops translation early
Frame shift mutation
Deletes or inserts a base to change the amino acids
Silent Mutation
A base is changed, but it codes for the same amino acid that it was originally supposed to
Which of the following cells would likely express the genes that code for glycolysis enzymes? • nerve cell • white blood cell • pancreas cell • all of these cells • none of these cells
All of these
Which of the following cells would likely express the genes that code for insulin? • nerve cell • white blood cell • pancreas cell • all of these cells • none of these cells
Pancreas
Which of the following cells would likely express the genes that code for hemoglobin? • nerve cell • white blood cell • pancreas cell • all of these cells • none of these cells
None of these
Construct an SBF Model of the Flow of Genetic Information
DNA replication –transcribe–> mRNA –translate–> Proteins
In DNA, what does A pair with? In RNA?
T; U
What does G pair with?
C
What direction do we read DNA?
5’ to 3’
Pyrimidines? How are their structures different from that of purines?
Thymine (T) and Cytosine (C); they have one ring
Purines? How are their structures different from that of pyrimidines?
A and G; they have two rings
What type of bond holds the base pairs together?
Hydrogen
What happens in interphase? (the sections)
G1, S, G2
G1
Gap 1; growth, increase of cytoplasm
S
Synthesis: DNA synthesis when DNA is replicated, we now have sister chromatids
G2
Gap 2; prep for division
Transcription
- From DNA to RNA; makes RNA from a DNA template
- uses a process that resembles the synthesis of a DNA strand during DNA replication
- Substitutes U for T
The figure diagrams the flow of genetic information in a eukaryote. Which of the following are the molecular-level equivalents of the terms: genotype and phenotype? (in that order) A. transcription; translation B. DNA; RNA C. DNA; Protein D. RNA; Protein
C
An organism’s genetic information is stored within the sequence of \_\_\_\_\_\_\_\_\_\_\_. This information is transcribed into a sequence of \_\_\_\_\_\_\_\_\_\_\_\_, which are then translated into a sequence of \_\_\_\_\_\_\_\_\_\_\_. A. DNA bases; amino acids; RNA bases B. RNA bases; DNA bases; amino acids C. amino acids; DNA bases; RNA bases D. DNA bases; RNA bases; amino acids
D
The conversion from the nucleic acid language to the protein language is called
Translation
The genetic code is
• redundant, with more than one codon for some
amino acids,
• unambiguous, in that any codon for one amino acid does not code for any other amino acid, and
• nearly universal, in that the genetic code is shared by organisms from the simplest bacteria to the most complex plants and animals.
5’CACGGUCGAUGAGGUUACAUCGC… 3’
Part of an mRNA molecule is shown above. If
this fragment came from the beginning of the mRNA, for which of the amino acid sequences below would it most likely code?
A. His-Gly-Arg
B. Thr-Val-Asp-Glu-Val-Thr
C. Met-Arg-Leu-His-Arg
D. Gln-Tyr-Ile-Gly-Val-Ala-Gly
D
3 main steps of transcription of a gene
- initiation, involving the attachment of RNA polymerase to the promoter and the start of RNA synthesis,
- elongation, as the newly formed RNA strand grows, and
- termination, when RNA polymerase reaches the terminator DNA and the polymerase molecule detaches from the newly made RNA strand and the gene.
Justin has type A blood and Brittany has type B. Both of their parents have type AB blood. What are the chances their son has type A blood. A. 100% B. 75% C. 25% D. 0%
D
Which direction does a daughter DNA strand grow?
5’ to 3’
True or False:
Introns are noncoding DNA sequences
True; thus extrons are coding
Which mutation changes an amino acid codon into a stop codon?
Non sense
Tumor suppressor genes are…
A. Inherited
B. Not inherited
Inherited
Mitosis is similar to…
Why?
Meiosis II b/c that’s when the sister chromatids split
A cell has 22 chromosomes plus 2 sex chromosomes. Which is likely the identity of this cell?
Eye cell of a female grasshopper
Linked genes are usually…
located close together on a chromosome
What chromosome belongs to a normal human female?
44 autosomes and 2X chromosomes
Woman has A blood, child has O blood. What is woman’s genotype?
I^A I^i
What are the five stages of Mitosis?
Prophase, Metaphase, Anaphase, Telophase, Cytokinesis
How is cytokinesis different for animal and plant cells?
Animals: Cleavage furrow
Plants: Cell plate
What is the difference between malignant and benign tumors?
Malignant: Spreads to other areas of body
Benign: Stays in one spot, not cancerous
What is metastasis?
Spread of cancer cells beyond original site
What is the difference between a haploid cell and a diploid cell?
Diploid: contains 2 sets of DNA (2n)
Haploid: Contains 1 set of DNA (n)
Growth factor
a protein secreted by certain body cells that stimulates other cells to divide
What are the eight stages of meiosis?
Prophase 1: Metaphase 1: Anaphase 1: Telophase 1: Prophase 2: Metaphase 2: Anaphase 2: Telophase 2:
Describe Crossing over
occurs during prophase 1; exchange of corresponding segments between non sister chromatids of homologous chromosomes
Describe independent assortment
random arrangements of chromosome pairs at metaphase 1 leads to many different combinations of chromosomes in eggs and sperm
Deletion
chromosome fragment becomes detached
Duplication
Segment is copied/inserted into homologous chromosome
Inversion
a fragment will reattach to the same chromosome in reverse orientation
Translocation
A fragment joins a non homologous chromosome
Leading strand vs lagging strand
continuous strand vs noncontinuous during DNA replication
Where is cap added
5’
Where is tail added
3’
What do cap and tail do?
protects mRNA and helps ribosomes
What are the 3 modifications made to mRNA before leaving the nucleus?
Addition of cap and tail, introns removed, exons spliced together
Are mutagens usually carcinogens?
Yes
Three components of a nucleotide
Sugar, phosphate group, nitrogen base
Function of DNA helicase
unzip
Function of DNA polymerase
Synthesis new DNA strand, add nucleotide to 3’
What direction is DNA synthesized?
5’ to 3’; read 3’ to 5’
What strand is top strand, what is bottom?
Leading bottom; Lagging top
DNA ligase
links nucleotides together to make a continuous strand
Differences between DNA and RNA
RNA:
- Single strand
- Sugar is ribose
- uracil instead of thymine
3 types of RNA
mRNA: made during transcription
tRNA:
rRNA:
Promoter
tells RNA polymerase where to begin
Elongation
making of RNA
Terminator
tells RNA polymerase where to stop transcribing
How many nucleotides codes for 1 amino acid?
3
Where is the anti codon
on the end of tRNA
start codon
AUG
What bond is formed between 2 adjacent amino acids?
peptide bonds
what ends elongation
termination
stop codon
UAC
Initiation establishes
where translation will begin
Three step elongation process
1 Codon recognition
2 Peptide bond formation
3 Translocation
Mitosis does not produce
sperm and eggs
Which of the following would likely express genes that code for hemoglobin?
- White blood
- Pancreas
- Nerve
- All
- None
None
Proto oncogene
not inherited
mutations potentially lead to cancer
Accelerator
Tumor Suppressor
- can be inherited
- brakes
- tell your cells to stop
- if mutation, it will be like broken brakes
How often do cells divide?
Depends on the type of cell
How to prokaryote reproduce
binary fission
Binary fission steps
- Duplication of chromosome and separation of copies
- Continued cell elongation and movements of copies
- Division into 2 daughter cells
Interphase includes
Def: duplication of cell contents
- G1
- S
- G2
Mitotic phase includes
Mitosis and Cytokinesis
Apoptosis
Programmed cell death
Check points
G1; G2; M-Checkpoint
Chromatin
Diffused form of DNA and its proteins
How many chromosomes do we have? (!!!)
46
Which form of cell division accounts for development of frog?
Mitosis
Sister chromatids
Duplicated identical chromosomes attached at centromere
A cell with 92 chromatids at the start of mitosis would, at its completion, produce cells containing how many chromosomes?
46
What is the Red Queen hypothesis?
- Organisms always compete with other organisms
- When one organism (predator) changes then the other (prey) must change as well
- Explains the advantages of sexual reproduction
Does synthesis occur during mitosis?
NO!