1-2 paragraphs would suffice in detail
Discuss social and cultural implications of when coffee was first introduce to Europe?
Describe one common class of aroma compound used in perfumery?
In: Biology
1.Which statement is true about nuclear fission or bombs?
A moderator slows down neutrons to make fission less likely.
The nuclear bomb dropped on Hiroshima in WWII was called Fat
Man.
A moderator slows down neutrons to make fission more likely.
The nuclear bomb in WWII that used 235U and a gun-type
design was called Fat Man.
The maximum amount of fissile material that will sustain a chain
reaction is called the critical mass.
Tries 0/2 |
The correct ranking of countries from highest to lowest for
either their total nuclear power generation or for their percentage
of electrical power from nuclear is:
Total nuclear power generation: France, U.S., China, South
Korea
Percentage of electrical power from nuclear : South Korea, U.S.,
France, China
Total nuclear power generation: France, South Korea, U.S.,
China
Percentage of electrical power from nuclear : U.S., South Korea,
France, China
Total nuclear power generation: U.S., France, China, South
Korea
Which statement is true about a nuclear reactor?
Adding the moderator to the reactor slows down fission.
A sudden loss of primary coolant water in a pressurized water
reactor slows down fission.
Removing the control rods from the reactor slows down
fission.
Removing the moderator from the reactor speeds up fission.
A sudden loss of primary coolant water in a pressurized water
reactor speeds up fission.
In: Biology
In: Biology
Give an example (with applicable reasoning) that explains why developing a HACCP plan could be difficult or challenging. What are two TCS foods that could be affected as a result of a breakdown in HACCP? Noting the importance of HACCP, and in light of HACCP's proven effectiveness, how would you meet the challenges?
In: Biology
Glucocorticoid secretion increases in response to
stress. Which of the following
hormones will cause the adrenal gland to release
glucocorticoids?
Growth hormone (GH)
adrenaline
Anti-diuretic hormone (ADH)
ACTH
During the Endocrine Ed simulation, what hormone secretion
increased when the
lights were turned out allowing Ed to sleep?
a.ACTH
b.adrenaline
c.thyroid stimulating hormone (TSH)
d.melanin
During labor, the baby's head pushes against the mother's cervix
causing nerve
impulses to transmitted to the brain to stimulate release of
oxytocin from the
pituitary gland into the blood stream. Increased levels of oxytocin
in the blood
stream stimulate uterine contractions which results in the baby's
head pushing
against the mother's cervix. The process repeats causing more and
more
oxytocin to be released into the blood stream stimulating stronger
and more
frequent contractions.
Is this an example of negative feedback?
a.Yes
b.No
Which of the following accurately describes the typical
transmission of an
electrical signal through a neuron?
a.cell body>dendrite>axon
b.axon>dendrite>cell body
c.axon>cell body>dendrite
d.dendrite>cell body>axon
Which of the following is defined as a small gap
between transmitting and
receiving neurons?
a.cell body
b.axon
c.synaptic terminal
d.synaptic cleft
Fill in the blanks with the correct word(s).
In the central nervous system (CNS), neurons bundled together are
called Blank 1.[ ]
. In the peripheral nervous system (PNS), neurons bundled together
are
called Blank 2 [.]
When you performed the "ruler catching" experiment, which of the
following
accurately describes the muscles used to catch the ruler?
a.sensory receptors
b.integration centers in the brain
c.effector cells
When a response "skips" the integration process where the brain
makes a decision about
how to respond to a stimulus, how would we describe this action by
the nervous system? In
other words, if a response to a stimulus is made involuntary
without conscious thought,
how would the relay system used by the nervous system be
described?
a.neural integration
.b.motor neuron output
c.sensory input
c.spinal reflex arc
In: Biology
In studying sub-populations of a small rodent that has a country wide distribution in the widely varying habitat of Costa Rica, Irena and Irwin (out intrepid evolutionary biologists) became interested in a gene with two alleles where one of the alleles (A1) produced an enzyme variety that protected mice from the venom of the “bushmaster” (a highly venomous snake) and the other allele (A2) produced an enzyme that protected the mice against the venom of the “fer de lance” (another highly venomous snake).
In habitats where both snakes are present in significant numbers, the genotype frequencies for were measured to be f(A1/A1) = 0.1; f(A1/A2) = 0.6; f(A2/A2) = 0.1. This represents a...
a) population in Hardy-Weinberg equilibrium showing the evolutionary pattern of selection for the heterozygote genotype.
b) population that is in Hardy-Weinberg equilibrium showing evidence of selection against the heterozygote.
c) population not in Hardy-Weinberg equilibrium showing the evolutionary pattern of selection for the heterozygote genotype
d) population that is not in Hardy-Weinberg equilibrium showing evidence of selection against the heterozygote.
If aggressive human intervention removed all of the snakes in the habitat described in the question above, which of the following would you not expect to happen to the allele and genotype frequencies in the population?
a) They would stay at exactly the levels they were at when the snakes were removed. b) One allele or the other could become fixed depending on the size of the rodent
population.
c) The number of heterozygotes would decrease. d) They would
fluctuate randomly due to drift.
In studying habitats where both snakes are present in significant numbers, Irwin and Irena found that over many generations, the allele frequencies tended to move first in one direction and then in the other but always tended to move back toward allele frequencies of f(A1) = 0.5 and f(A2) = 0.5. This could be an example of...
a) frequency dependent selection b) selection for a
dominant
c) selection for a recessive
d) underdominance
In one particular habitat with a small rodent population size but where both snakes were present in significant numbers, the genotype frequencies were measured to be relatively close to f(A1/A1) = 0.38; f(A1/A2) = 0.24; f(A2/A2) = 0.38. This could be an example of...
a) overdominance
b) inbreeding
c) directional selection
d) mutation-selection balance
In: Biology
Explain how the type of disease, Thalassemia affects the skeletal system. Is the disorder systemic or focal and how does this affect it’s manifestation on or in the bones.
In: Biology
Which population shows genetic drift?
A. A population of harvest mice disappears from an area after a devastating flood. |
B. Wolves in an island population have redder fur than mainland wolves due to the genetic makeup of the first wolf colonizers. |
C. A chickadee population moves to an area that has more seed-bearing plants. |
D. A population of tansy begins to bloom later in fall as the climate changes. |
In: Biology
What are the steps involved in creating a vaccine? What are researchers looking for and how is FDA approval achieved?
In: Biology
5. Name the structure and functions of four cellular organelles.
In: Biology
1. What prediction does the neutral theory make that is not true and what modification was made to its assumptions to produce a new theory created by Ohta that better fit the data?
A) genetic change should be constant/most mutations are under very weak selection
B) evolutionary rate should be a function of mutation rate per generation/most mutations are under very weak selection
C) evolutionary rate should be a function of mutation rate per generation/drift is not acting
D) evolutionary rate should be a function of mutation rate per generation/most mutations are under very strong selection
E) genetic change should be constant/most mutations are under very strong selection
2. In a hypothetical situation a flu pandemic is spreading across the world (in humans). The virus is sequenced and is found to be an H1N3 virus. A phylogeny of viruses find that this virus is most closely related H1N1 viruses but that the gene for N3 is most closely related to the 'N' gene in pigs. What is the most likely evolutionary scenario for this situation?
A) The pig virus has switched hosts to attack humans
B) Human and pig viruses recombined in a host cell
C) Human and pig viruses mated and recombined
D) The viral gene for 'N' underwent extensive parallel evolution
E) N1 mutated to N3
In: Biology
Select all of the following that are used to predict protein coding genes from a genome sequence
ORF detection |
||
cDNA |
||
Codon Bias |
||
BLAST searches to identify similar DNA or protein sequences |
Unique DNA sequences are harder to assemble when creating a whole genome sequence than repetitive DNA sequences
True
False
In: Biology
"Here we report results of a field experiment in which the number of plant species was experimentally controlled (Fig. 1 legend). Our 147 plots, located on nitrogen-limited soil24, were planted with either 1, 2, 4, 6, 8, 12, or 24 species. The species assigned to each plot were chosen by a separate random draw of the appropriate number of species from a pool of 24 North American prairie species. The impacts of diversity on plant productivity, nutrient capture and nutrient leaching were observed during the second year of growth. We also sampled a native grassland to determine the relationships between these variables in an undisturbed mature ecosystem. Treatments created an experimental biodiversity gradient. THE functioning and sustainability of ecosystems may depend on Plant species richness, Shannon diversity (H1 and effective their biological diversity1-a. Elton's' hypothesis that more diverse ecosystems are more stable has received much attention 1,.3 6,,7 10- 14, but Darwin's proposal615 that more diverse plant communities are more productive, and the related conjectures,4.s1 6.17 that they have lower nutrient losses and more sustainable soils, are less well studied 4-6,s,t, 7 l8_ Here we use a well-replicated field experi ment, in which species diversity was directly controlled, to show that ecosystem productivity in 147 grassland plots increased significantly with plant biodiversity. Moreover, the main limiting nutrient, soil mineral nitrogen, was utilized more completely when there was a greater diversity of species, leading to lower leaching loss of nitrogen from these ecosystems. Similarly, in nearby native grassland, plant productivity and soil nitrogen utilization increased with increasing plant species richness. This supports the diversity-productivity and diversity-sustainability hypotheses. Our results demonstrate that the loss of species threatens ecosystem functioning and sustainability. The diversity-productivity hypothesis is based on the assump tion that interspecific differences in the use of resources by plants allow more diverse species richness (e8 ' ; Fig. la) were all significantly correlated with the number of species seeded into the plots (Pearson's r = 0.81, r = 0.74, r = 0.75, respectively; n = 147, P < 0.001 for all). Two measures of peak standing crop (our estimate of plant productivity) were positively correlated with the species-richness treatment (total plantcover:r 0.39,n = 147,P < 0.001, Fig. lb; biomass estimated by light penetration: r = 0.27, n = 147, P < 0.001). Both estimates were similarly dependent on observed plot species richness (rcover = 0.55, rbiomass = 0.42, n = 147, P < 0.001 for both) and effective species richness (rcover = 0.29, rbiomass = 0.29,n = 147,P < 0.001 for both). Thus, greater plant diversity led to greater productivity during the second year of ecosystem establishment."
Can someone draw and explain the experimental design, thank you!
In: Biology
If we added a high concentration (which will permeabilize the phospholipid bilayer) of strong detergents to beet samples, would this result in high or low absorbance value at 460 nm? Explain.
In: Biology
1. When comparing a range of viral populations in a particular year what characteristic is most associated with survival of the population to the next year.
A) a high rate of change in sequences at antigenic sites
B) a high rate of change in sequences generally
C) movement to a new host
D) ability to overwhelm the immune system
E) a low mutation rate
2. Some sharks migrate from the ocean to live in a freshwater lake. After a few generations scientists sequence an enzyme involved with moving ions across cell membranes in both the ancestral ocean population and the lake population. After correcting for the number of possible changes they found 3.3 nonsynonymous changes in the sequence for every synonymous change. This is evidence for which of the following?
A)No selection on the enzyme
B)Positive (directional) selection on the enzyme
C)Negative (stabilizing) selection on the enzyme
D)Ambiguous (disruptive) selection on the enzyme
3. Which evolutionary forces will tend to cause populations to diverge from one another genetically when they (the populations) are geographically isolated?
A) mutation, drift, selection
B) mutation, drift, migration
C) migration, drift, mutation
D) migration, selection
E) migration, selection, drift
In: Biology