Genetics Flashcards
A pea plant produces purple and yellow peas. Cross pollination of a homozygous yellow pea plant with a homozygous purple pea plant produces pea plants each with a mixture of approximately 50% yellow and 50% purple peas in their pods. This is an example of __
Codominance
Choose the correct definition for a gene
DNA sequence which codes for a protein
Choose the correct definition for locus
position/location of a gene on a chromosome
Two genes are most likely to experience independent assortment if __
they are located for apart on the same chromosome and they are on different chromosomes
Recessive alleles __
require two copies to be expressed in the phenotype
Dominant alleles __
require one copy to be expressed in the phenotype
The interaction of multiple genes with the environment to determine a characteristic that shows continuous variation is known as __
polygenic inheritance
An autosome is __
non sex chromosome
Colorblindness is an x linked recessive condition. A colorblind male and a female who is a carrier for colorblindness are planning to have a baby. What is the probability that the couple will have a male child who is colorblind?
25%
Which of the following blood types are considered “universal donors”
O
Which of the following blood types are considered “universal acceptors”
AB
A white rat mates with a black rat and produce a full litter of grey offspring. This is an example of __
incomplete dominance
In a molecule of DNA or RNA, the phosphodiester bond forms between __
3’ carbon and a 5’ carbon
Which of the following is not a RNA nitrogenous base?
thymine
Which of the following nitrogenous bases are pyrimidines?
cytosine, thymine, and uracil
Which of the following describes the action of helicase in DNA replication?
breaking hydrogen bonds between nucleotides
In eukaryotic DNA replication bubble forms at __ sites on the DNA molecule and moves in __
multiple, bond the 5’–> 3’ and 3’–> 5’ directions
Okazaki fragments form because __
DNA polymerase can only synthesize in the 5’–> 3’ direction
In a molecule of DNA, Adenine typically pairs with __
Thymine
DNA replication occurs during which phase of the cell cycle?
interphase
DNA replication is described as semi conservative because __
each new DNA molecule contains one of the original strands and one newly synthesized strand
In prokaryotic DNA a replication bubble forms at __ site on the DNA molecule and moves in __
one, both the 5’–> 3’ and 3’–> 5’ directions
Which type of sugar is found in a nucleic acid molecule?
pentose
Which of the following helps to keep DNA strands in the replication bubble separate during replication?
single stranded binding proteins
Which of the following describes the action of ligase in DNA replication?
joining the ends of DNA fragments together
In DNA replication, the difference between the leading and lagging strand is __
the leading strand is synthesized continuously and the lagging strand is synthesized discontinuously
Which of the following describes the action of telomerase in eukaryotes?
to add repeating nucleotide sequence to the end of DNA strands
Which of the following is believed to play a role in the aging process?
telomere shortening after successive DNA replications
The function of telomeres is__
to protect the ends of DNA from deterioration
In DNA replication, a primer __
is a short sequence of RNA used as a template for elongation by DNA polymerase
Eukaryotic transcription is carried out by a __
DNA dependent RNA polymerase
How many codons code for amino acids?
61
The term “monocistronic” means __
one polypeptide is coded for by each mRNA molecule
Which of the following is found in the promoter region in eukaryotes?
TATA box
RNA polymerase “reads” the DNA molecule in the __ direction and synthesizes the mRNA molecule in the __ direction
3’–> 5’, 5’–>3’
Which of the following is not a stop codon?
UAU
In transcription, the template strand is also known as the __ strand, while the non template strand is also known as the __ strand.
antisense, sense
Which of the following occurs during termination of transcription?
the DNA double helix reforms, RNA polymerase reaches a termination sequence, the mRNA molecule is released from DNA
Which event triggers the termination of transcription?
RNA polymerase reaches a termination sequence on the DNA
Which of the following include proteins that bind to the promoter region of a gene and modulate the rate of transcription?
transcription factors
Addition of a 5’ cap and poly-A tail to an mRNA molecule occurs in the __
nucleus
Which of the following correctly describes the purpose of “alternative splicing” in protein synthesis
to form multiple proteins from a single gene
Which of the following facilitates the removal of noncoding regions from the pre mRNA molecules
snRNPs
Which of the following describes the role of snRNPs in protein synthesis
removal of introns from mRNA
The complex which removes noncoding regions from pre mRNA molecules in eukaryotes is the __
spliceosome
Which of these are added to a eukaryotic mRNA molecule during mRNA processing?
poly A tail and 5’ cap
The purpose of the poly A tail in a molecule of eukaryotic mRNA __
to allow export across the nuclear membrane and to increase the stability of mRNA
The coding regions of pre mRNA transcript are called
exons
Which of the following is responsible for translation in protein synthesis?
ribosomes
The first amino acid in a growing polypeptide chain during translation in prokaryotes is __
N-formylmethionine
Which event triggers the termination of translation?
a stop codon enters the A site of the ribosome
Wobble base pairing typically occurs when __
the third nucleotide in the codon or anticodon do not follow Watson Crick base pairing
The first codon translated on a eukaryotic mRNA is __
AUG
During initiation of Eukaryotic translation on a ribosome, the first aminoacyl-tRNA molecule binds to the mRNA transcript at the __
peptidyl site
At the end of initiation of eukaryotic translation on a ribosome is complete, which of the following are vacant?
amino acyl and exit site
Which of the following occurs during initiation of translation?
the 5’ end of mRNA binds to the small ribosomal unit, tRNA methionine binds to the start codon, the large ribosomal subunit attaches to the complex
Which of the following cofactors facilitates the translocation of the mRNA molecule through the ribosome?
GTP
Which of the following facilitates the folding of a polypeptide into its tertiary conformation?
chaperone proteins
In translation, polypeptide chains are synthesized from the __ terminus to the __ terminus
amino, carboxyl
To increase the expression of a gene __ proteins bind to __ regions on DNA
activator, enhancer
Regulatory proteins which block the expression of genes are called __
repressors
Regulatory proteins which increase the expression of genes are called __
activators
To decrease the expression of a gene in prokaryotes __bind to __ on DNA
repressors, operators
Which of the following are methods of post transcriptional control of gene expression?
alternative splicing, polyadenylation of mRNA, addition of 5’ CAP to mRNA, binding of siRNA to mRNA
Which of the following influences how many times an mRNA transcript is translated?
the stability of the mRNA transcript
What affect, if any, does the 5’ CAP of mRNA have on protein production?
promotes translation, prevents mRNA degradation
Which of the following is not a method of transcriptional regulation of gene expression in eukaryotes?
alternative splicing
Which of the following do transcription factors bind to?
promoters upstream of a gene, enhancers downstream of a gene, RNA polymerase
Which of the following describes the effect of alternative splicing on gene expression?
alternative splicing controls which proteins are produces from an mRNA transcipt
mRNA is degraded by __
exonucleases
Epigenetic modifications of DNA involve alterations to
chromatin structure
Which of the following is not a possible epigenetic modification of DNA
gene transposition
Regulation of eukaryotic gene expression can occur by acetylation of __
histones
What DNA nucleotide is most commonly methylated?
cytosine
The result of DNA methylation in eukaryotes is __
gene inactivation
Histone acetylation involves adding an acetyl group to which of the following amino acids?
Lysine
Which of the following results from acetylation of histones?
less condensed chromatin structure
Which of the following DNA modifications may alter gene expression?
methylation
x chromosome inactivation is achieved by which of the following
DNA methylation and histone deacetylation
An inactive X chromosome is known as __
Barr body
Which of the following are short RNA sequences which block gene expression?
siRNA
The effect of siRNA binding to an mRNA transcript is __
degradation of the mRNA transcript
Which of the following describes how micro RNAs regulate gene expression
promoting mRNA degradation and inhibiting translation
Which of the following describes the recombinant DNA technique known as gene cloning?
the desired gene is inserted into a plasmid and taken up into the host cell
Recombinant DNA is __
DNA which contains sections of DNA from multiple organisms
Which of the following enzymes is used to cut DNA in recombinant DNA techniques?
restriction endonuclease
Which of the following enzymes is used in the insertion of foreign DNA into a plasmid?
DNA ligase
Unpaired nucleotides produced after the treatment of double stranded DNA with restriction enzymes are known as __
sticky ends
The process by which a plasmid is introduced into bacterial cells is known as __
tranformation
Which of the following techniques is commonly used during transformation to enable the bacteria to make up a recombinant plasmid?
heat shock treatment
Which of the following explains how gel electrophoresis can be used to separate DNA fragments?
shorter DNA molecules move further towards the anode than larger molecules
The migration distance of a protein on an SDS polyacrylamide gel is primarily determined by __
size
Which of the following refers to the annealing of complementary DNA strands?
hybridization
Which of the following techniques would be used to amplify a sample of DNA obtained at a crime scene for forensic analysis?
polymerase chain reaction
Put the following steps of a single round of PCR in the correct order.
denaturation, annealing, elongation
Polymerase chain reaction is used to __
to make large quantities of DNA from small samples
Which enzyme is used for the elongation step in PCR?
taq polymerase
Which of the following is used for the denaturation of DNA during PCR?
heating over 90 degrees celsius
Reverse transcriptase synthesizes __
DNA from mRNA
DNA which is synthesized from a single stranded RNA molecule is known as __
complementary DNA
How does complementary DNA differ from the parent DNA sequence for eukaryotes?
it does not contain introns
Which of the following would be most useful in measuring the expression level of multiple genes simultaneously?
DNA microarray
Which of the following are used in DNA analysis to positively match a DNA sample to an individual?
short tandem repeats
The full set of mRNA expressed by a cell is known as the __
transciptome
Which of the following is a genetic sequencing method which used fluorescent markers to synthesize one DNA fragment at a time?
sanger sequencing
In comparison with the eukaryotic genome, prokaryotes have
smaller genomes with higher gene density
Regions of DNA that have become non functional in a species over time due to mutation are known as
pseudogenes
The percentage of the human genome which codes for proteins is approximately
1.5%
Which of the following describes the process of transposition in retrotransposons?
“copy and paste” transposition using an RNA intermediate
What are multigene families?
similar or identical gene sequences that have resulted from duplication of a single origin gene
Which of the following is a 180bp DNA sequence that codes for a DNA binding domain in genes which regulate structural development?
homeobox
Most genetic sequences in human DNA are __
transposable elements
Which of the following refers to a single base variation in the gene sequences of individuals?
single nucleotide polymorphisms
Which of the following processes results in formation of three distinct germ layers in the embryo?
gastrulation
Which of the following is a phase of embryonic cell division without growth?
cleavage
Place the following in order of progression in embryonic development.
morula, blastula, gastrula
The term given to a single cell capable of forming a complete embryo is __
totipotent
Programmed cell death in normal cell development is known as __
apoptosis
The cellular product of zygotic cleavage is known as a __
blastomere
Which of the following is the process by which developing embryonic stem cells form specialized cells with different structures and functions
differentiation
Embryonic ectodermal tissue would form which of the following?
brain
Which of the following describes the transition of an embryo from morula to blastula phase?
outward movement of embryonic epithelial cells to form a circular fluid filled cavity
Embryonic endodermal tissue would form which of the following
lung tissue
Which of the following structures formed in the gastrula phase of an embryo will later become part of the vertebral column?
notocord
Embryonic mesodermal tissue would form which of the following?
cardiac muscle
The difference between a morula embryo and a zygote is __
the morula is multicellular whereas the zygote is unicellular
Embryonic stem cells are found within which of the following?
blastocyte
The rapid period of mitotic cell division which occurs following fertilization of an egg is known as __
cleavage
Which of the following structures in an embryo will later become the spinal cord?
neural tube
The fluid filled cavity of an embryo in the blastula phase is known as the __
blastocoel
The acrosomal reaction of sperm involves __
digestion of the zone pellucida of the oocyte membrane
The human form of an embryo in blastula phase is known as a __
blastocyst
After successful implantation to the endometrium, which of the following is released from the developing embryo?
hcG hormone
The blastocyst transitions into a gastrula by which of the following processes?
invagination of embryonic epithelial cells
The outer layer of a blastocyst which will form the placenta is called the __
trophoblast
Which of the following processes results in formation of a morula embryo from a zygote?
rapid cleavage
Which of the following is the first major event in organogenesis?
neural tube formation
Which of the following is the mouth like opening on the surface of an embryo in the gastrula phase?
blastopore
