Answer:
Heart valves or the closure of the mitral and tricuspid atrioventricular (AV) valves at the beginning of ventricular systole and the closure of the aortic valve and pulmonary valve at the end of ventricular systole.
Explanation:
The heart tone “lub,” or S1, is caused by the closure of the mitral and tricuspid atrioventricular (AV) valves at the beginning of ventricular systole.
The heart tone “dub,” or S2 ( a combination of A2 and P2), is caused by the closure of the aortic valve and pulmonary valve at the end of ventricular systole.
in chemical reactions, bonds blank in reactants.
Choose THREE examples that correctly predict the effect of a change on the ecosystem.
А
A decrease in the kangaroo rat population will cause a decrease in the coyote
population
B
A decrease in the desert tortoise population will cause a decrease in the
rattlesnake population
Wc
A decrease in the rattlesnake population will cause an increase in the kangaroo
Answer:
The answer is option A "A decrease in the kangaroo rat population will cause a decrease in the coyote population"
Explanation:
Climate is a significant ecological impact on environments. Changing Climate influences biological systems in an variety of ways. For example, warming may constrain species to relocate to higher scopes or higher rises where temperatures are more helpful for their endurance.
Environmental change not just influences biological systems and species straightforwardly, it likewise communicates with other human stressors, for example, advancement. Although a few stressors cause just minor effects when acting alone, their combined effect may prompt emotional natural changes. For example, environmental change may worsen the pressure that land improvement puts on delicate water front zones. Also, as of late logged forested zones may get defenseless against disintegration if environmental change prompts increments in substantial down pour storms.
The correct sequence for the general adaptation syndrome is:_________
a) Exhaustion phase, alarm phase and resistance phase
b) Alarm phase, resistance phase and exhaustion phase
c) Resistance phase, exhaustion phase and alarm phase
d) Alarm phase, exhaustion phase and resistance phase
Answer:
The correct sequence for the general adaptation syndrome is: b) Alarm phase, resistance phase and exhaustion phase
Explanation:
The general adaptation syndrome describes what happens to our body when it is under stress.
The first phase is the Alarm phase. In this stage, the body activates the fight or flight response, causing an increase in adrenaline and cortisol, blood pressure, respiratory frequency, amongst other things that prepare us to react in a situation that we perceive as dangerous.
The second phase is the resistance one. During this phase, the body undergoes a different process that adapts it to manage the stress, with an elevated amount of cortisol and blood pressure.
The third phase is the exhaustion phase. If the stress levels continue to be high, the body passes to this stage. The body is exhausted and cannot keep dealing with stress, which causes mental and physical problems such as anxiety, depression, fatigue, stress-related illnesses, among other symptoms.
Discuss the roles of the enzymes secreted by the pancreas during digestion.
how do organelles interact in the production and use of hemoglobin found in theses cells
Answer:
B
Explanation:
Answer:B
Explanation:
Bacterial disease is caused by the multiplication of bacteria in a patient. How do pathogenic bacteria harm a patient?
Answer:
Host Susceptibility
Resistance to bacterial infections is enhanced by phagocytic cells and an intact immune system. Initial resistance is due to nonspecific mechanisms. Specific immunity develops over time. Susceptibility to some infections is higher in the very young and the very old and in immunosuppressed patients.
Bacterial Infectivity
Bacterial infectivity results from a disturbance in the balance between bacterial virulence and host resistance. The “objective” of bacteria is to multiply rather than to cause disease; it is in the best interest of the bacteria not to kill the host.
Host Resistance
Numerous physical and chemical attributes of the host protect against bacterial infection. These defenses include the antibacterial factors in secretions covering mucosal surfaces and rapid rate of replacement of skin and mucosal epithelial cells. Once the surface of the body is penetrated, bacteria encounter an environment virtually devoid of free iron needed for growth, which requires many of them to scavenge for this essential element. Bacteria invading tissues encounter phagocytic cells that recognize them as foreign, and through a complex signaling mechanism involving interleukins, eicosanoids, and complement, mediate an inflammatory response in which many lymphoid cells participate.
Genetic and Molecular Basis for Virulence
Bacterial virulence factors may be encoded on chromosomal, plasmid, transposon, or temperate bacteriophage DNA; virulence factor genes on transposons or temperate bacteriophage DNA may integrate into the bacterial chromosome.
Host-mediated Pathogenesis
In certain infections (e.g., tuberculosis), tissue damage results from the toxic mediators released by lymphoid cells rather than from bacterial toxins.
Intracellular Growth
Some bacteria (e.g., Rickettsia species) can grow only within eukaryotic cells, whereas others (e.g., Salmonella species) invade cells but do not require them for growth. Most pathogenic bacteria multiply in tissue fluids and not in host cells.
Virulence Factors
Virulence factors help bacteria to (1) invade the host, (2) cause disease, and (3) evade host defenses. The following are types of virulence factors:
Adherence Factors: Many pathogenic bacteria colonize mucosal sites by using pili (fimbriae) to adhere to cells.
Invasion Factors: Surface components that allow the bacterium to invade host cells can be encoded on plasmids, but more often are on the chromosome.
Capsules: Many bacteria are surrounded by capsules that protect them from opsonization and phagocytosis.
Endotoxins: The lipopolysaccharide endotoxins on Gram-negative bacteria cause fever, changes in blood pressure, inflammation, lethal shock, and many other toxic events.
Exotoxins: Exotoxins include several types of protein toxins and enzymes produced and/or secreted from pathogenic bacteria. Major categories include cytotoxins, neurotoxins, and enterotoxins.
Siderophores: Siderophores are iron-binding factors that allow some bacteria to compete with the host for iron, which is bound to hemoglobin, transferrin, and lactoferrin.
Explanation:
What are the Complementary DNA base pairs: ATTGGCCTAGC *
Answer:
taaccggatcg
Explanation:
Give the mRNA and amino acid sequence of the DNA code below.
DNA Code: TAC AAA ACC ATG ACT
mRNA Codon: ___ ___ ___ ___ ___
amino acid: ___ ___
___ ___ ___
What would happen to a cell if its cytoplasm contains 97% water and 3% solute and it is placed into a container that has a solution of 92% water and 8% solute?
A cell if its cytoplasm contains 97% water and 3% solute and it is placed into a container that has a solution of 92% water and 8% solute - cell will lose water and shrink.
A hypertonic solution, the solution has a lower water concentration than the cell cytosol, and water moves out of the cell until both solutions are isotonic
if you place a cell in a hypertonic solution, the cell shrinksit loses water as due to osmosis water moves from a higher concentration inside the cell to a lower concentration outsideThe water will move out of the cell to try to equalize.Thus, A cell if its cytoplasm contains 97% water and 3% solute and it is placed into a container that has a solution of 92% water and 8% solute - cell will lose water and shrink.
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What are the Complementary DNA base pairs: GGGCCATATAG. What are the Complementary DNA base pairs: ATTGGCCTAGC
Answer:
CCCGGTATATC
TAACCGGATCG
Explanation:
G and C are complimentary; T and A are complimentary
Just swap each letter following that rule :)
What are the properties of water that you can observe when transpiration takes place?
Answer:
When water evaporates through the leaves, a pull is created through the xylem, and water moves back to the leaves. This is known as the transpiration pull.
How do abundant growth and care resources affect ecosystem?
Answer:
over exploitation
Explanation:
What effect does dietary protein have on the body?
Answer:
Dehydrating effect
Explanation:
Answer:
Dietary protein serves several important functions. It provides the essential amino acids, which are used for protein synthesis in the growth and repair of tissue, and it is the body's principal source of nitrogen.
Iridium (Ir) is a rare element on Earth, but common in
asteroids
volcanoes
the oceans
icy comets
Which layer affects the oceanic and continental plates here on Earth?
Answer:
lithosphere
Explanation:
In hummingbirds feather color is incompletely dominant. A rather large population of hummingbirds has 396 red-sided individuals (RR), 257 brown sided individuals (Re) and 557 tan-sided individuals orr). Calculate the following:_______.
a. What is the allele frequency of the Rallele (o)?
b. What is the allele frequency of the rallele (a)?
Migration season comes and 200 of the red-sided individuals leave the nosulation before mating occurs.
c. After migration season what is the new allele frequency of the Rallele (0)?
d. After migration season, what is the new allele frequency of the rallelelo?
e. Which mechanism of evolution (natural selection, genetic drift, or gene flow) caused the allele frequencies to change?
Answer:
a) Frequency of the R allele: [(396 x 2) + 257] / (396 x 2) + (257 x 2) + (557 x 2) = 1049 / 2420 = 0.433
b) Frequency of the r allele: [(557 x 2) + 257] / (396 x 2) + (257 x 2) + (557 x 2) = 1371 / 2420 = 0.567
c) Frequency of the R allele: [(196 x 2) + 257] / (196 x 2) + (257 x 2) + (557 x 2) = 649 / 2020 = 0.321
d) Frequency of the r allele: [(557 x 2) + 257] / (196 x 2) + (257 x 2) + (557 x 2) = 1371 / 2020 = 0.679
e) migration is gene flow
Explanation:
Gene flow (also referred to as gene migration) is the movement of genes that acts to change allele frequencies in local populations by transferring genetic material from one population to another. Gene flow may be caused either by the movement of organisms that reproduce in new populations (migration), or by the movement of gametes (for example, pollen dispersal in plants).
PLEASEEE HELPPPPP!!!!!!!
which aquatic ecosystem is the most commercially exploited for seafood and minerals.
Answer:
The coral reefs of the Caribbean are thought to be under threat
Explanation:
Overfishing threatens over 60 percent of Caribbean coral reefs. Declines in coral cover and increases in algal cover have been observed across the region. This analysis identified about one-third of Caribbean reefs at high threat from overfishing pressure and about 30 percent at medium threat.
identify the type of mutation shown in the diagram, with respect to chromosome 20
Which of the following is NOT a property of water?
O A) It is a good solvent.
OB) It is denser when frozen than when liquid.
OC) It resists temperature changes.
OD) it is cohesive.
O El It can be found as a solid. liquid. or gas.
Answer:
It is denser when frozen than when liquid.
Explanation:
Ice is actually less dense than water. The lattice arrangement of ice allows water molecules to be more spread out than in a liquid, making ice less dense than water.
Hope that helps.
If you are building a dichotomous key and you have 10 species to identify, how many couplets should your key have?
A) 04
B) 05
C) O9
D) 10
Answer:
10
Explanation:
easch couplet presents the user with 2 alternatives and exclusive sets of character's.
10 couplets should your key have. If you are building a dichotomous key, and you have 10 species to identify. Hence, option D is correct.
What is dichotomous key?A dichotomous key, a crucial piece of scientific gear, is used to discriminate between diverse species according to their visible traits. Users must choose one of two possibilities to answer a series of questions that make up dichotomous keys.
A dichotomous key in the identification of trees, for instance, would ask whether the tree has leaves or needles. The key then leads the user down one set of questions if the tree has leaves; if the tree has needles, a different set of questions is shown.
The three most prevalent types of dichotomous keys are nested, connected, and branched. Each sentence has the appropriate response written next to it in nested type.
Thus, option D is correct.
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Urinary Journey
Name:
For your journey through the urinary system you must be made small enough to be filtered through the filtration
membrane from the bloodstream Into the renal You will be injected into the subclavian vein and must
pass through the heart before entering the arterial circulation. As you travel through the systemic circulation you have
a least 2 minutes to relax before reaching the ___(2).__artery, feeding the kidney. You see the kidney looming
brownish red through the artery wall. Once inside, the blood vessels of the kidney become increasingly smaller until
finally you reach the _3_ arteriole, feeding into the filtering device, or ____.Once in the filter, you
maneuver yourself so that you are directly in front of a pore. Within a fraction of a second, you are swept across the
filtration membrane into the (5)_ part of the nephron. Drifting along, you lower the specimen cup to gather
your first filtrate sample for testing. You study the readout from the sample and note it is very similar in composition to
_66) with one exception. There are essentially no ____. Your next sample doesn't have to be taken
until you reach the "hairpin" or using proper terminology the_8__. As you continue your journey, you notice
that the tubule cells have dense fingerlike projections extending from there surface into the lumen of the tubule.
These are which increase the absorptive surface area because this part of the tubule is very active in the
process of __(10)_ . While in the "hairpin" you collect your second sample. The readout verifies that the
concentration of the filtrate is much ___(11) and there are few nutrients such as ____(12)__and
(13)__.There is a much higher concentration of _(14) wastes here and the color is yellow, indicating
the presence of the pigment_(15)_ Gradually, you make your way up from the "hairpin and enter into an area
where large molecules are being moved into the filtrate you know you have arrived in the (16) and are
witnessing the process of_(12)_ You continue along and realize that the water level has dropped and the
stream have become more turbulent. You remember the role of the hormone_(18)__and think it must have
been released to conserve water in the body. You take an abrupt right and then drop straight downward into a tube
that has other tubes and fluid entering into it. You realize you are in the_(19)_ headed for the rinor calyx. You
enter into a much calmer are and flow very tranquilly Into a tube on the opposite shore. Upon entrance into this tube
you realize you are being squeezed rhythmically downward and you know you are in the _(20) _ Suddenly you
free-fall and splash into a large sea of urine, you know you have arrived at the _(21)
_There appears to be a lot
of fluld as the celling is getting closer and closer to you and suddenly the walls begin to gyrate and in a moment you are
being propelled out and into your hosts__ _(22) to exit the body.
Answer:for your journey through the urinary system you must be made small enough to be filtered through the filtration
membrane from the bloodstream Into the renal You will be injected into the subclavian vein and must
pass through the heart before entering the arterial circulation. As you travel through the systemic circulation you have
Explanation:
The urinary system, sometimes referred to as the renal system, manages fluid and electrolyte balance as well as filters and eliminates waste items from the body.
How does the urinary system work?You must be reduced in size to pass through the filtration membrane and into the renal system on your voyage via the urinary system. The subclavian vein will be used as the injection site, and you must first pass through the heart to reach the arterial circulation. You have at least two minutes to unwind as you move through the systemic circulation before you arrive at the renal artery, which supplies the kidney.
Through the artery wall, you can make out the towering, brownish-red kidney. Once within, the kidney's blood arteries get progressively smaller until you reach the afferent arteriole, which feeds into the glomerulus, the filtering organ. Once inside the filter, you position yourself such that you are facing a pore directly. You are quickly carried across the filtration membrane and into the Bowman's capsule region of the nephron. You lower the specimen cup as you proceed to collect your first test sample of filtrate.
You examine the reading from the sample and discover that, with one exception, its chemical makeup is very identical to that of blood. Practically no blood cells exist. You can wait to take your next sample until you get to the Henle loop, or the "hairpin" in correct language. You observe the tubule cells as you proceed along your path because they have numerous thick fingerlike projections that protrude into the tubule lumen from their surface.
This portion of the tubule is relatively small, therefore these microvilli improve the absorptive surface area. You gather your second sample while in the "hairpin". The readout confirms that the filtrate's content is significantly lower and that few nutrients, including glucose and amino acids, are present.
Here, metabolic wastes are substantially more concentrated, and the area is yellow, which denotes the presence of the urochrome pigment. You know you have arrived in the distal convoluted tubule and are seeing the process of secretion when you gradually work your way up from the 'hairpin' and enter into an area where big molecules are being transported into the filtrate.
As you proceed, you notice that the streams are now more agitated and the water level has plummeted. You recall the function of the hormone ADH and assume that the body must have secreted it to save water. You make a sharp right and then plunge straight down into a tube that is being filled with fluid and other tubes. You become aware that you are moving towards the minor calyx in the collecting duct.
You move very calmly into a tube on the other coast after entering a much calmer area. You become aware that you are experiencing a rhythmic downward squeeze as soon as you enter this tube, indicating that you are in the ureter. You know you have arrived to the urinary bladder when you suddenly drop and splash into a sizable sea of urine. As you can see, there is a lot of fluid as the ceiling gets closer to you and the walls start to pull. Suddenly, you are propelled out of the body and into your host's urethra to leave the body.
Therefore, the urinary system, sometimes referred to as the renal system, manages fluid and electrolyte balance as well as filters and eliminates waste items from the body.
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What is the role of energy in living organisms? Is ti a mor or less important role than other characteristics of life?
Answer:
A huge number of chemical reactions take place continuously in a living cell. The whole of all chemical processes, that is, the total turnover of matter and energy is called metabolism.
Explanation:
All organisms need the energy to grow, reproduce, and respond to their surroundings. All these processes are achieved through metabolism that allows the energy available to them.
What kind of features would you expect to find in a transitional
fossil between Ichthyostega and Eusthenopteron?
Answer:
hope that help you
Explanation:
Fossils or organisms that show the intermediate states between an ancestral form and that of its descendants are referred to as transitional forms. There are numerous examples of transitional forms in the fossil record, providing an abundance of evidence for change over time.
Pleaseeee help!!! (psychology edge) Androgens and estrogens are hormones that impact the sexual response cycle. Write about the four phases of that cycle and explain how the two types of hormones are involved.
Answer:
Females and males each have some amount of the sex hormones, androgens and estrogens. In males however, androgens like testosterone is more dominant and in females estrogens like estradiol are more dominant. The hormones both affect the sexual response cycle. The sexual response cycle has four phases: desire, arousal, orgasm and resolution. The desire phase can last anywhere from a few minutes to hours and includes physical changes like an increase in muscle tension, heartbeats quickening, flushed skin, and an increased flow of blood to genitals. The arousal phase extends to the brink of the orgasm phase, during this phase the changes experienced in the desire phase are intensified along with blood pressure increasing. The orgasm phase generally only lasts a few seconds and is the climax of the sexual response cycle, some characteristics include: Involuntary muscle contractions and spasms, blood pressure, breathing, and heart rate at their highest point, a release of built up sexual tension, and flushed skin. During the resolution phase the body returns to normal, often a sense of wellbeing and fatigue is achieved. To begin the cycle a male need a certain amount of the androgen, testosterone, but high levels in females tend to lead to more sexual thought and desires, typically though, women have relatively low levels of testosterone. In women, estrogens, such as estradiol are more common. Estrogens are produced when a girl starts puberty and helps her reproductive cycle begin. A high level of estrogen in men can lead to a reduced sex drive, loss of hair, or trouble focusing, but a normal level in men is crucial to proper erectile function.
Explanation:
I just submitted this, i hope it helps :)
Which microscope is used to check organelles of human cheek cell?
Answer:
4x or 10x
Explanation:
You need one of those to find the cells and then you can increase magnification
What part of earth absorbs most sunlight
Answer:
The atmosphere
Explanation:
Answer:
The equator.
Explanation:
"The equator receives the most solar radiation in a year. The difference in the amount of solar energy the land receives causes the atmosphere to move the way it does."
I wasn't so sure about this question. During my research, the internet says atmosphere, equator, and then oceans. I believe it's more of the equator than anything, but there are three choices to choose from.
I hope this helps!
The smallest unit of life is a ,and all organisms have at least one.
Answer: A cell
Explanation:
Answer:
Cell
Explanation:
It just is. :/
dy÷dx=(x-1)(x+3) at x=2
Answer:
[tex]\dfrac{dy}{dx}=\dfrac{4}{25}[/tex]
Explanation:
The given expression is :
[tex]y=\dfrac{(x-1)}{(x+3)}[/tex]
We need to find dy/dx at x = 2
[tex]\dfrac{dy}{dx}=\dfrac{d}{dx}(\dfrac{x-1}{x+3})\\\\=\dfrac{(x+3)\dfrac{d}{dx}(x-1)-(x-1)\dfrac{d}{dx}(x+3)}{(x+3)^2}\\\\=\dfrac{x+3-(x-1)}{(x+3)^2}\\\\=\dfrac{x+3-x+1}{(x+3)^2}\\\\\dfrac{dy}{dx}=\dfrac{4}{(x+3)^2}[/tex]
Put x = 2 in above expression
[tex]\dfrac{dy}{dx}|x=2=\dfrac{4}{(2+3)^2}\\\\=\dfrac{4}{25}[/tex]
Hence, the value at dy/dx is [tex]\dfrac{4}{25}[/tex]
Scenario 1
When you think of the American Southwest, you probably think of cacti, both big and small. If you were to
visit the American Southwest today, you might be disappointed with the lack of variation among cactus
species, especially right off the major highways. In 1926, Route 66 was the nation's first major highway to
allow visitors to visit the Southwest. Like many tourists, these visitors wanted to take home a memento of
their travels. Many people would pull over and begin looking for their own living souvenir. Since many of the
tourists did not have the necessary tools to extract a spiny cactus out of the soil, they usually had to make a
conscious decision about what type of cactus they should dig up. The cacti with too many spines were seen
as too difficult to dig out, and the visitors likely didn't have gloves to protect their hands. The cacti with too
few spines were seen as homely and were often overlooked. Therefore, the tourists found a cactus that was
between these two extremes. Over the last century, the phenotypic variation within these small cacti has
changed (at least in areas accessible by these highways).
why is energy flow through an ecosystem dependent upon continual energy transformations?
Answer:
Organisms must gather energy to survive.
Explanation:
Answer:
food
Explanation: