final exam two Flashcards
Why would you use a test cross?
to identify an unknown genotype of the same phenotype
Which of the following statements does NOT correctly describe the role of the protein during DNA replication?
- Helicase breaks the hydrogen bonds between the nitrogenous bases to unwind DNA
-DNA polymerase adds nucleotides on the newly synthesized strand
-Primase adds an RNA primer
-RNA polymerase removes the RNA primer
RNA polymerase removes the RNA primer
Transcription factors are made of what type of biomolecule polymers?
proteins
Promoter sequences are made of what type of biomolecule polymers?
nucleic acids
splicing together exons
Two identical joined copies of a replicated chromosome are called
sister chromatids
Two chromosomes that are the same size, same shape, same genes in the same place but can have different alleles are called
homologous chromosomes
Mitosis produces…
identical daughter cells
What does meiosis do…
reduces the number of chromosomes in half
anaphase
telophase/cytokinesis
prometaphase
metaphase
Sister chromatids form during what phase
s phase
In what phase do you prepare for mitosis and make proteins for spindle
g2 phase
in what phase does sister chromatids separate
m phase
What is the central dogma?
The catalyst for the making of the phosphodiester bond is
the enzyme DNA polymerase
In dna replication which one is the template strand
old
3 to 5
non coding
put the following DNA replication events in order
2-5-1-4-6-3
What happens after mRNA is transcribed
(4 things)
- 5 cap is added
- 3 poly a tail is added
- splicing occurs
- mRNA is exported to cytoplasm
A mutation is
-usually within a gene
-a phenotype that has been changed by a mutagen
-an incorrect sequence that causes a disease
-any change in the nucleotide sequence of the DNA
-any change in the RNA made during transcription
any change in the nucleotide sequence of the DNA
RNA Polymerase catalyzes WHAT. The enzyme makes the new RNA in the WHAT direction. The synthesized RNA is read by the ribosome in the WHAT
RNA Polymerase catalyzes RNA synthesis. The enzyme makes the new RNA in the 5’ –> 3’ direction. The synthesized RNA is read by the ribosome in the 5’ –> 3’
A cell cycle “checkpoint” would be best described as:
specific stages where further progress of the cell cycle can be halted
The color of a bird is governed by a single gene. Blue is the dominant trait while white is the recessive trait. If you have a blue bird how can you determine if it is heterozygous or homozygous for the dominant trait?
Cross the blue bird to a white bird
mRNA is made using what as a template?
DNA sequence
what are the coding and template strand in this
transcription is initiated at DNA regions called…
promoters
transcription factors bind to…
the promoter
what catalyzes transcription
RNA polymerase
mRNA is read by a ribosome in three nucleotide units called…
codons
what is a codon
three nucleotide units that codes for an amino acid or stop signal
what are the three main types of RNA
mRNA (messenger)
tRNA (transfer)
rRNA (ribosomal)
what are the 5 components for translation
-mRNA
-factors (initiation, elongation, release)
-amino acyl tRNA synthetases
-tRNA
rRNA
what are amino acyl tRNA synthetases
enzymes that charge tRNA
what does the E site do
holds the tRNA that will exit
what does the P site do
holds the tRNA with growing polypeptide chain attached
what does the A site do
holds the aminoacyl tRNA
when AUG is found it joins with what site
P
what happens after AUG binds with the P site
met tRNA and initiation factors are released and another tRNA complementary to the next codon binds to the A site
what is elongation
ribosome shifts one codon to the right, which moves uncharges tRNA to E site and next tRNA to P site making the A site free
what is termination
elongation continues till a STOP codon is in the A site, release factor binds to A site and polypeptide is released from tRNA
what is the steps of transcription
- transcription factors bind to the promoter
- transcription factors recruit RNA polymerase and open up the helix
- RNA polymerase uses DNA as template to make new RNA
What happens after mRNA is transcribed
- 5 cap is added
- 3 poly A tail is added
- splicing occurs
- mRNA is exported to cytoplasm
sexual reproduction increases genetic diversity through what key mechanisms
- homologous recombination (crossing over)
- independent assortment
- random fertilization
what is homologous recombination
crossing over
what is an allele
alternative forms of a gene that lead to different traits
alleles are different versions of what
alleles are different versions of a gene
what is genotype
the genetic composition of an individual
letters of Homozygous dominant
AA
letters of hetrozygous
Bb
letters of homozygous recessive
dd
what is phenotype
the appearance of an individual
genetic makeup of a cell or organism
genotype
observed characteristics
phenotype
different forms of any gene
alleles
two copies of the same allele
homozygous
two copies of different alleles
heterozygous
true breeding
physical appearance of offspring is identical to parents
A true-breeding black rabbit is crossed with a true-breeding white rabbit to produce an F1 generation of 16 individuals. If the black color trait is dominant, which of the outcomes represents the expected phenotype of an F1 generation cross?
all black rabbits
In the F2 generation of a homozygous yellow-seed (AA) X homozygous green-seed (aa) cross in peas, two peas are chosen at random. What is the probability that one is homozygous yellow (AA) and the other is homozygous green (aa)?
(1/4) x (1/4) = (1/16)
Suppose that in humans the ability to roll the tongue (R) is dominant to being unable to roll it (r). Having freckles (F) is dominant to having no freckles (f). A freckled tongue-roller could have which genotypes?
RrFf
RRFF
DNA replication in what phase results in sister chromatids
S phase
What are components necessary for eukaryotic transcription?
RNA polymerase, general transcription factors, DNA, and RNA nucleotides
A template DNA strand contains the sequence 5’-ATGCTGAC-3’. The corresponding sequence in the RNA transcript is:
5’-GUCAGCAU-3’
If you made a change in the promoter sequence in the DNA that inactivates the promoter, what would happen at the RNA level?
The RNA polymerase would not be able to recognize and bind the DNA, so no RNA would be made
What is the name of the enzyme complex that is responsible for synthesis of RNA?
RNA polymerase
true or false
All RNA is translated to generate proteins
false
