3919717
Descripción
Test por Chinwendu Opara, actualizado hace más de 1 año
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Creado por Chinwendu Opara
hace casi 9 años
|
|
Pregunta 1
Pregunta
What characterizes a prokaryotic cell?
Respuesta
-
presence of a nucleus with no DNA
-
lack of ribosomes
-
having a cell wall without a cell membrane
-
lack of a membrane-enclosed nucleus
-
presence of mitochondria
Pregunta 2
Pregunta
Which of the following is NOT considered a weak molecular interaction?
Respuesta
-
hydrogen bond
-
van der Waals interactions
-
covalent bond
-
ionic bond in the presence of water
Pregunta 3
Pregunta
Acid rain has lowered the pH of a particular lake to 3.0. The hydrogen ion concentration of the lake is
Respuesta
-
10^3
-
10^-10 M
-
10^-3 M
-
3%
-
3.0 M
Pregunta 4
Pregunta
A cation always has:
Respuesta
-
more protons than neutrons
-
more electrons than protons
-
equal numbers of protons and electrons
-
more protons than electrons
Pregunta 5
Pregunta
Nucleotides are important in
Respuesta
-
All of the preceding
-
energy production and utilization
-
transmission of hereditary information
-
nucleic acid organization
Pregunta 6
Pregunta
Water is able to form hydrogen bonds because
Respuesta
-
the oxygen atom in water molecules is weakly negative
-
the hydrogen in water molecules is weakly positive
-
All of the above are correct
-
the water molecule is polar
Pregunta 7
Pregunta
The unique sequence of amino acids in a polypetide:
Respuesta
-
quaternary structure of a protein
-
primary structure of a protein
-
tertiary structure of a protein
-
secondary structure of a protein
Pregunta 8
Pregunta
An enzyme accelerates a metabolic reaction by
Respuesta
-
making the substrate molecule more stable
-
pushing the reaction away from equilibrium
-
altering the overall free-energy change for the reaction
-
lowering the activation energy
Pregunta 9
Pregunta
Which of the following organelles is common to plant and animal cells?
Respuesta
-
mitochondria
-
centrioles
-
tonoplast
-
chloroplasts
-
wall made of cellulose
Pregunta 10
Pregunta
Which of the following components is present in prokaryotic cell?
Respuesta
-
nuclear envelope
-
mitochondria
-
endoplasmic reticulum
-
ribosomes
-
chloroplasts
Pregunta 11
Pregunta
On which of the following features do most plant and animal cells differ?
Respuesta
-
structure of nucleus
-
primary energy source
-
transcription
-
mitochondrial function
-
active transport mechanisms
Pregunta 12
Pregunta
If a sexually reproducing species has a chromosome number of 2n=16, then:
Respuesta
-
it is diploid with 32 chromosomes
-
its gametes contain 16 chromosomes
-
it received 8 chromosomes from the egg and 8 chromosomes from the sperm
-
it has 16 different pairs of chromosomes
Pregunta 13
Pregunta
A biochemist isolated and purified molecules needed for replication. When DNA was added, replication occurred but the DNA molecules were defective. Each consisted of a normal DNA strand with many DNA segments a few hundred nucleotides long. What has the biochemist left out of the mixture?
Respuesta
-
nucleotides
-
DNA polymerase
-
Okazaki fragments
-
primers
-
ligase
Pregunta 14
Pregunta
A microbiologist found that some bacteria infected by phages had developed the capacity to make a particular amino acid that they did not make before. The new capacity probably reflects
Respuesta
-
transduction
-
induction
-
conjugation
-
transposition
-
transformation
Pregunta 15
Pregunta
Which of the following is not true of a codon? A codon
Respuesta
-
is a basic unit of genetic code
-
never codes for more than one amino acid
-
may code for the same amino acid as another codon
-
extends from a tRNA molecule
Pregunta 16
Pregunta
The cells of the liver are distinct from cells of the spleen because they
Respuesta
-
have different chromosomes
-
use different genetic codes
-
express different genes
-
have unique ribosomes
-
contain different genes
Pregunta 17
Pregunta
Which of the following techniques would you use to produce a great number of DNA copies?
Respuesta
-
fingerprinting
-
gel electrophoresis
-
hybridization
-
autoradiography
-
polymerase chain reaction
Pregunta 18
Pregunta
All of the following compounds are required at some stage of photosynthesis EXCEPT
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-
NADP
-
carbon dioxide
-
oxygen
-
water
-
adenosine triphosphate
Pregunta 19
Pregunta
Which of the following would never contribute to genetic variation within a bacterial population?
Respuesta
-
conjugation
-
mutation
-
meiosis
-
transformation
-
transduction
Pregunta 20
Pregunta
The final electron acceptor of the electron transport chain that functions in oxidative phosphorylation is
Respuesta
-
lactate
-
NAD+
-
water
-
pyruvate
-
oxygen
Pregunta 21
Pregunta
During human gestation, organogenesis occurs
Respuesta
-
in the first trimester
-
during the blastocyst
-
during the embryo
-
while the embryo is in the oviduct
-
in the second trimester
Pregunta 22
Pregunta
Organogenesis begins with the development of the
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-
neural tube (brain & spinal chord)
-
coelom
-
archenteron
-
blastocoel
-
blastopore
Pregunta 23
Pregunta
Programmed cell death occurs normally in the development of the nervous and immune systems. This is termed
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-
totipotency
-
differentiation
-
determination
-
pattern formation
-
apoptosis
Pregunta 24
Pregunta
Mammals are distinguished from other vertebrates by the presence of
Respuesta
-
an amniote egg
-
a four chambered heart
-
cephalization
-
hair and mammary glands
Pregunta 25
Pregunta
As humans diverged from other primates, which of the following most likely appeared first?
Respuesta
-
the development of culture
-
an enlarged brain
-
an erect stance
-
language
-
toolmaking
Pregunta 26
Pregunta
The major endothermic (warm blooded) vertebrates include the
Respuesta
-
mammals and birds
-
reptiles
-
mammals
-
birds
-
birds and reptiles
Pregunta 27
Pregunta
Which of the following enzymes acts first during digestion?
Respuesta
-
amylase
-
pepsin
-
trypsin
-
lipase
-
nuclease
Pregunta 28
Pregunta
In which of the following blood vessels would you expect to find the most nutrients?
Respuesta
-
aorta
-
hepatic portal vein
-
intestinal artery
-
posterior vena cava
-
renal portal vein
Pregunta 29
Pregunta
The various metabolic exchanges occur in
Respuesta
-
veins
-
capillaries
-
muscular arteries
-
venules
-
elastic arteries
Pregunta 30
Pregunta
Pulse is a direct measure of
Respuesta
-
stroke volume
-
blood pressure
-
heart rate
-
cardiac output
-
breathing rate
Pregunta 31
Pregunta
Compared to interstitial fluid that bathes active muscle cells, blood reaching these cells in arteries has a
Respuesta
-
higher partial pressure of O2
-
lower osmotic pressure of CO2
-
higher partial pressure of CO2
-
lower pH
Pregunta 32
Pregunta
Humoral immunity is mediated primarily by
Respuesta
-
B lymphocytes
-
T lymphoctes
-
neutrophils
-
monocytes
-
macrophages
Pregunta 33
Pregunta
HIV compromises the immune system primarily by infecting _______ cells
Respuesta
-
helper T
-
cytotoxic
-
B
-
suppressor
-
plasma
Pregunta 34
Pregunta
Fertilization of human eggs most often takes place in the
Respuesta
-
uterus
-
vagina
-
vas deferen
-
oviduct (fallopian tube)
-
ovary
Pregunta 35
Pregunta
The nitrogenous waste generated by an animal is best correlated with the animals _______ metabolism.
Respuesta
-
nucleic acid and lipid
-
protein
-
protein and nucleic acid
-
nucleic acid
-
lipid
Pregunta 36
Pregunta
The concept that recognizes that the internal environment is maintained at an optimal level is termed
Respuesta
-
euryhaline
-
stenaline
-
adaptation
-
osmoconformatory
-
homeostasis
Pregunta 37
Pregunta
The functional units of the kidney control blood composition through
Respuesta
-
ultrafiltration
-
secretion
-
reabsorption
-
all of the preceding
Pregunta 38
Pregunta
The coordination of movement is mediated by the
Respuesta
-
thalamus
-
medulla
-
cerebellum
-
pons
-
cerebrum
Pregunta 39
Pregunta
The largest and most complex part of the human brain is the
Respuesta
-
cerebellum
-
cerebral cortex
-
pituitary
-
medulla oblongata
-
hypothalamus
Pregunta 40
Pregunta
Of the following components of the nervous system, which is the most inclusive?
Respuesta
-
central nervous system
-
spinal cord
-
neuron
-
brain
-
gray matter
Pregunta 41
Pregunta
Which scientific name is presented correctly?
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-
Apis mellifera
-
Drosophila Melanogaster
-
limuls polyphemus
-
rana Pipiens
-
Caenorhabditis elegans
Pregunta 42
Pregunta
A single bacterium existing in an environment with unlimited resources and no competition would
Respuesta
-
reproduce logistically
-
reproduce exponentially
-
reproduce linearly
-
reproduce radially
-
not reproduce
Pregunta 43
Pregunta
___________ capacity is the maximum number of individuals of a species an environment can support.
Respuesta
-
none of the preceding
-
carrying
-
population
-
growth
-
habitat
Pregunta 44
Pregunta
Which of the following compounds is the most common compound in the bacterial cell wall?
Respuesta
-
cellulose
-
capsule
-
lignin
-
lipopolysaccharide
-
peptodoglycan
Pregunta 45
Pregunta
A mycelium consists of
Respuesta
-
cellular slime molds
-
pseudoplasmodia
-
fibrils
-
microtubules
-
hypahe
Pregunta 46
Pregunta
Genes that regulate development are conserved. This means that they
Respuesta
-
have evolved large differences among multicellular organisms
-
none of the above
-
have changed very little over the course of evolution
-
are always turned on
Pregunta 47
Pregunta
During translation, polypeptide chain elongation requires the __________ enzymatic activity
Respuesta
-
poly-A polymerase
-
peptidyl transferase
-
methyl transferase
-
glycyl-tRNA synthetase
Pregunta 48
Pregunta
Which of the following processes occurs in the cytoplasm of a eukaryotic cell?
Respuesta
-
DNA replication
-
transcription
-
DNA replication and translation
-
translation and transcription
-
translation
Pregunta 49
Pregunta
By executing a test cross, the genotype of an organism that expresses a dominant trait can be determined by
Respuesta
-
crossing the organism with a heterozygous dominant organism
-
crossing the organism with a homozygous dominant organism
-
crossing the organism with a homozygous recessive organism
-
observing the phenotype of the progeny from any cross
-
observing the genotype of the progeny from any cross
Pregunta 50
Pregunta
Ribosomes are a collection of __________ that are needed for ____________.
Respuesta
-
proteins and rNAs; translation
-
small proteins; translation
-
proteins and tRNAs; transcription
-
proteins and mRNAs; translation
-
mRNAs and tRNAs; translation
Pregunta 51
Pregunta
The genetic code is degenerate because
Respuesta
-
amino acids may have more than one codon
-
each codon codes for only one amino acid
-
both A &B
-
neither A nor B
Pregunta 52
Pregunta
Epistasis refers to
Respuesta
-
group of genes that are close together
-
the equal interaction of two genes so that a new phenotype is produced
-
the expression of two genes in the same individual
-
the linear order of genes on a chromosome
-
the expression of one gene making the expression of another
Pregunta 53
Pregunta
FOR QUESTIONS 54, 55, 56 & 57 BASE RESPONSE ON THE FOLLOWING INFORMATION
In a species of tropical bird, wing feather coloration is controlled by the action of 6 loci: R, D, G, Y, A and B, alleles R and r, D and d, etc. Complete dominance occurs at each locus.
The R and D loci exhibit additive gene action: R__ D__ bird have dark red wings; rrdd birds have pink wings; and all other genotypic combinations at these loci result in birds with pale red wings.
The G locus is dominantly epistatic to the R and D loci; G__ birds exhibit green wing coloration. The Y locus is recessively epistatic to the R,D and G loci; yy birds have yellow wings. The A and B loci control pigment production and are recessively epistatic to the color loci; aa and/or bb birds have white wings [i.e. dominance is required at both loci for pigment production].
RrDdGgYyAaBb x rrddggYYAaBb
(just click "okay bih" in answer options)
Respuesta
-
okay bih
-
tell me something good *song tune*
Pregunta 54
Pregunta
From the mating above, what proportion of the progeny would be expected to exhibit the paternal phenotype?
Respuesta
-
9/128
-
3/16
-
6/32
-
1/128
Pregunta 55
Pregunta
From the mating above, what proportion of the progeny would be expected to exhibit the maternal phenotype?
Respuesta
-
1/16
-
9/16
-
1/4
-
9/32
Pregunta 56
Pregunta
An inbred pale red wing female is mated with a white male. The F1 (subscript 1) progeny are mated among themselves. What is the largest proportion of the F2 (subscript 2) progeny that would be expected to exhibit green wing feathers?
(I didn't have the answer for this one and I'm way too sleepy to figure it out)
Respuesta
-
3/8
-
1/16
-
9/16
-
3/16
-
I DONT KNOW
Pregunta 57
Pregunta
A green winged female is mated with a yellow winged male. What is the largest proportion of their progeny that would be expected to exhibit pale red wings?
Respuesta
-
1/16
-
1/8
-
1/2
-
3/4
-
all
Pregunta 58
Pregunta
Which phrase regarding a Mendelian monohybrid cross is incorrect? It
Respuesta
-
demonstrates independent assortment
-
demonstrates segregation of only one pair of alleles
-
gives two phenotypic classes
-
gives three phenotypic classes
Pregunta 59
Pregunta
Which statement about chromosome number is incorrect?
Respuesta
-
each type of chromosome is represented twice in a diploid cell
-
gametes usually contain only one set of chromosomes, referred to as haploid
-
a human somatic cell has one pair of sex chromosomes
-
sister chromatids of a chromosome are genetically identical and constitute a homologous pair
Pregunta 60
Pregunta
During meiosis, when are homologous pairs of chromosomes separated?
Respuesta
-
anaphase II
-
metaphase II
-
meiosis I
-
no answer is correct
Pregunta 61
Pregunta
What is the pattern of inheritance for a rare recessive allele?
Respuesta
-
very affected person has an affected parent
-
affected parents do not produce affected children
-
unaffected parents can produce children who are affected
-
unaffected mothers have affected sons and daughters who are carriers
-
none of the above
Pregunta 62
Pregunta
There are 46 chromosomes in a human diploid cell. How many autosomes are present in an egg cell?
Respuesta
-
44
-
2
-
1
-
22
Pregunta 63
Pregunta
_________ is the term for an allele that has more than one distinguishable phenotypic effect.
Respuesta
-
heterosis
-
epistasis
-
codominance
-
incomplete dominance
-
pleiotropy
Pregunta 64
Pregunta
Experiments conducted by Meselson and Stahl demonstrated that DNA replication is
Respuesta
-
semiconservative
-
semidiscontinous
-
conservative
-
bi-directional
Pregunta 65
Pregunta
Nucleotides are composed of:
Respuesta
-
ribose sugar ad phosphates
-
ribose sugars and nitrogenous bases
-
nitrogenous bases and phosphates
-
both b and c
Pregunta 66
Pregunta
Which of the following is a normal human female?
Respuesta
-
XY
-
XXY
-
XXX
-
XX
Pregunta 67
Pregunta
For double helical DNA (This is Chargaff's Rule):
Respuesta
-
A+T/G+C always approximates 1.0
-
A+T/G+C always approximates 0.5
-
A+G/T+C always approximates 1.0
-
A+G/T+C always approximates 1.5
Pregunta 68
Pregunta
A human somatic cell contains _____ chromosomes.
Respuesta
-
23
-
47
-
2n
-
46
-
n
Pregunta 69
Pregunta
In transcription,
Respuesta
-
DNA makes DNA
-
DNA makes RNA
-
RNA makes a polypetide chain
-
RNA makes DNA
Pregunta 70
Pregunta
Which of the following processes occurs in the cytoplasm of the eukaryotic cell?
Respuesta
-
DNA replication
-
translation
-
transcription
-
DNA replication translation
-
translation and transcription
Pregunta 71
Pregunta
Which of the following series represents alleles:
Respuesta
-
Aa
-
AB
-
Ab
-
ab
Pregunta 72
Pregunta
In the human body, gametes are produced by
Respuesta
-
mitosis
-
meiosis
-
binary fission
-
multiple fission
Pregunta 73
Pregunta
During replication in E. coli, DNA is maintained as single-stranded molecules at replication fork by:
Respuesta
-
helicase
-
SSB proteins
-
primase
-
DNA ligase
Pregunta 74
Pregunta
The problem of replication on the lagging strand is solved by DNA through the use of
Respuesta
-
base pairing
-
replication
-
the unwinding enzyme, helicase
-
Okazaki fragments
-
topoisomerases
Pregunta 75
Pregunta
DNA polymerase I synthesis new molecules of DNA in:
Respuesta
-
a 3' to 5' direction
-
a 5' to 3' direction
-
both a and b
Pregunta 76
Pregunta
The two strands of double helical DNA are held together by
Respuesta
-
covalent bonds
-
ionic bonds
-
hydrogen bonds
-
disulfide bonds
Pregunta 77
Pregunta
The genotypic ratio in a cross between a homozygous recessive and a heterozygous (aa x Aa) is:
Respuesta
-
3:1
-
1:2
-
9:3:3:1
-
1:1
Pregunta 78
Pregunta
Processing of primary transcripts results in
Respuesta
-
mRNA precursors
-
polypetides
-
intervening sequences
-
mature mRNAs
Pregunta 79
Pregunta
smRNPs are involved in:
Respuesta
-
translation
-
DNA replication
-
splicing
-
posttranslation modification of proteins
Pregunta 80
Pregunta
What is the difference between DNA and a chromosome:
Respuesta
-
chromosomes contain DNA within their structure
-
DNA often incorporate a chromosome into its mass
-
chromosomes fill the nucleus while DNA is in the nuclear membrane
-
they are essentially the same
Pregunta 81
Pregunta
A couple who are both carriers for the gene for cystic fibrosis have two children who have cystic fibrosis. What is the possibility that their next child will have cystic fibrosis?
Respuesta
-
0%
-
75%
-
100%
-
25%
-
50%
Pregunta 82
Pregunta
If factor "a" is lethal in the homozygous condition, "aa", then how many offsprings out of every 16 will survive from the cross AsBb x AaBb?
Respuesta
-
3
-
12
-
16
-
9
Pregunta 83
Pregunta
Given the parents AABBCc x AabbCc, assume simple dominance and independent assortment. What proportion of the progeny will be expected to phenotypically resemble the first parent?
Respuesta
-
1/4
-
1
-
3/8
-
3/4
-
1/8
Pregunta 84
Pregunta
What role do herbivores (organisms that eat plants) play in the energetics of ecosystems?
Respuesta
-
consumers
-
reducers
-
decomposers
-
producers
Pregunta 85
Pregunta
Which gas is most abundant in earth's current atmosphere?
Respuesta
-
oxygen
-
nitrogen
-
carbon dioxide
-
argon
Pregunta 86
Pregunta
Denitrification:
Respuesta
-
occurs in anerobic conditions
-
converts nitrogen gas to ammonia
-
converts nitrate to nitrate
-
is carried out by Rhizobium bacteria
Pregunta 87
Pregunta
Most of the earth's carbon is found in:
Respuesta
-
tree trunks and living biomass
-
sedimentary rocks
-
atmosphere
-
ocean
Pregunta 88
Pregunta
A female African elephant produces a single offspring at interval levels of several years, caring for her young for an extended period before reproducing again. The elephant's reproductive life history is referred to as:
Respuesta
-
semelparous
-
iteroparous
-
indeterminate
-
progamic
Pregunta 89
Pregunta
Offspring from a sexual union contribute only one-half as much to the evolutionary fitness of either parent as asexually produced offspring. This relative reduction in fitness is called:
Respuesta
-
the Red Queen hypothesis
-
dioecy
-
the cost of meiosis
-
sequential hermaophroditism
Pregunta 90
Pregunta
Desert shrubs competing for scarce supplies of water are likely to show which dipersion pattern?
Respuesta
-
aggregate
-
regular
-
random
-
clumped
Pregunta 91
Pregunta
When predators and their prey exhibit cyclic population oscillations, the typical pattern is:
Respuesta
-
predator number increases after prey number increases
-
prey number increases after predator number increases
-
both predator and prey cycles are nearly identical (synchronous peaks)
-
no predictable relationship between predator and prey population sizes
Pregunta 92
Pregunta
Hummingbirds will chase away other birds that attempt to visit backyard feeders. This interaction is an example of:
Respuesta
-
mutualism
-
allelopathy
-
exploitation competition
-
interference competition
Pregunta 93
Pregunta
The relationship between plants and their insect pollinators is best described as:
Respuesta
-
amensalism
-
commensalism
-
defensive mutualism
-
dispersive mutualism
Pregunta 94
Pregunta
Which of the following nutrient elements typically limits primary production in fresh water?
Respuesta
-
potassium
-
calcium
-
nitrogen
-
phosphorus
Pregunta 95
Pregunta
Which of the following ecosystems has a level of production similar to a tropical rain forest?
Respuesta
-
marsh
-
desert
-
open ocean
-
temperate grassland
Pregunta 96
Pregunta
Mycorrhizal fungi aid in supplying what critical element to plant roots?
Respuesta
-
oxygen
-
phosphorus
-
carbon
-
nitrogen
Pregunta 97
Pregunta
Production of large sized offspring is most likely linked to:
Respuesta
-
high competition among juveniles
-
wind dispersal of offspring
-
production of large numbers of offspring
-
increased survivorship of parents
Pregunta 98
Pregunta
The predominant sexual system in flowering plants is:
Respuesta
-
hermaphroditic
-
unisexual
-
monoecious
-
dioecious
Pregunta 99
Pregunta
When a population grows according to the logistic model, what is the value of "r' when the population numbers are stable?
Respuesta
-
r = 0
-
r = K
-
r = N
-
r = 1/2 K
Pregunta 100
Pregunta
All of the following are plant secondary compounds used for defense against herbivores EXCEPT:
Respuesta
-
spines
-
alkaloids
-
terpenoids
-
tannins
Pregunta 101
Pregunta
Keystone predators can increase species diversity in a community because:
Respuesta
-
they eat most kinds of species
-
they allow species to live outside of their ecological range
-
they prevent prey from eating each other
-
they may prevent a superior competitor from becoming dominant
Pregunta 102
Pregunta
The first few years of succession on an abandoned agricultural field are characterized by a community of:
Respuesta
-
annual and biennial herbaceous plants
-
shrubs
-
trees
-
perennial herbaceous plants
Pregunta 103
Pregunta
The largest single source of anthropogenic (human-caused) increase in atmospheric carbon dioxide:
Respuesta
-
cattle ranching
-
mining
-
making fertilizer
-
burning fossil fuel
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