Which of the cardiac cell characteristics describes the
ability to initiate an electrical impulse?
Answer:
The correct answer is: automaticity.
Explanation:
Cardiac muscle has several properties. These properties are: automaticity (given by the pacemaker cells), conductivity (meaning that each cardiac cell can transmit the electrical impulse to the next cardiac cells), contractility (like other types of muscles, cardiac muscle cells can contract), and irritability (each cell can contract on its own without the external stimuli).
Cardiac pacemaker cells are the ones with the capacity to initiate the electrical impulse by creating rhythmic impulses called action potentials, and thus directly regulating heart rate.
Pacemaker cells are located in the sinoatrial (SA) node, in the upper portion of the right atrial wall. In these cells, depolarization of the cardiac muscle begins, and the electrical impulse generated by it is transmitted to the atrioventricular (AV) node, the His bundle and then the Purkinje fibers - this order of events is necessary for the correct contraction of the heart to occur. All of these structures are part of the Conduction System of the heart.
Which of the following is a unifying characteristic of life?
Answer:
where is option I can't see
D - Telophase
C - Anaphase
A - Prophase
B - Metaphase
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Choose the correct description for each phase of mitosis.
Answer:
A-B-C-D
Explanation:
PROPHASE; 1. chromosomes become thicker
2. nuclear membrane disintegrates
3. centrosome divide to form centrioles
4. centrioles move to the opposite polls of the cell
METAPHASE; 1. chromosomes get arranged at the equator
2. centrioles produce spindle fibre that attach to the middle of the chromosomes
ANAPHASE; 1. shortest stage of mitosis
2. spindles will pull apart each chromosomes to form chromatids
TELLOPHASE; 1. each chromatid moves to opposite polls of the cell
2. nuclear membrane appears around both of them
3. the centrioles sill stop producing spindles
4. centrosomes will then form again
cytokinesis then divides by the cleavage furrow to form the two daughter cells
Two species of closely related frogs are found in the same pond high in the Andes of South America. Both species only have teeth on the top jaw. One has small teeth for holding small live prey prior to swallowing. The other species has very large sharp teeth for injuring and killing large prey prior to biting off pieces of flesh for consumption. The above is an example of:
Complete question:
Two species of closely related frogs are found in the same pond high in the Andes of South America. Both species only have teeth on the top jaw. One has small teeth for holding small live prey prior to swallowing. The other species has very large sharp teeth for injuring and killing large prey prior to biting off pieces of flesh for consumption. The above is an example of:
Directional selectionAnalogous structuresCharacter displacementHybridization Vestigial structuresAnswer:
Character displacementExplanation:
Competition is an ecological and evolutive process very common in nature. Competition might be intra- or interspecific. Competition between different species in a community or ecosystem might be due to the same resource use, or the same territory, shelter, etcetera. When a resource is useful for two or more species, and limited, they compete to gain it.
The principle of competitive exclusion states that different species with the same requirements sharing the niche can not coexist indefinitely based on the same limited resource. When two competing species coexist, this is because of niche partitioning or niche differentiation.
Differentiation of effective niche is closely related to character displacement.
Character displacement is the result of interspecific competition, in which two or more species that live in the same habitat manage to avoid competition by developing different traits. Morphological divergence, or any adaptative trait development, fixated genetically, is the product of niche segregation. Species tend to differentiate morphologically in the presence of strong competitors. Traits divergence favors coexistence in the same place.
In the exposed example, both species live in the same pond. But to avoid competition and competitive exclusion, species developed different teeth sizes to feed on different prey items.
I need help asap
I need help asap
Answer:
c
Explanation:
i dont care
A degraded ecosystem is replaced with a different but productive ecosystem type, one that might even include some nonnative species. For example, a degraded forest might be replaced with a productive pasture.a. passive restoration b. remediation c. partial restoration d. rehabilitation e. complete restoration
Answer:
d. rehabilitation
Explanation:
Technology-associated rehabilitation is an ecological practice that allows a degraded area to be restored, rehabilitating all its degraded habitats. However, this restoration is not done naturally, but is caused by human intervention, which can cultivate the entire plant population in the area, even adding non-native species, which are selected to leave the productive area, but ecologically harmonious.
2 True or False. A projectleie an object that once set in motion continues in motion by its own martia O True False
Answer:
The answer is true.Explanation:PARTICLES MOVING ALONG THE PATH POSSES A TWO DIMENSIONAL MOTIONMARK ME AS BRAINIST PLZ
Using sophisticated molecular cloning techniques, you have isolated the genes for two serotonin transporters, called TransA and TransB, which are expressed in these neuronal cells. A preliminary immunofluores- cence localization of fixed and permeabilized cells found very bright staining of TransA at the nerve cell plasma membrane and little staining elsewhere. TransB, in contrast, stained only very faintly at the nerve cell plasma membrane, but there was intense staining within the cytosol.
Required:
In which subcellular membrane or organelle would you expect most of the TransB to be found? Explain your answer.
Answer:
Vesicles
Explanation:
Serotonin is a neurotransmitter that transports signals or messages between neurons.
Most neuronal cells have vesicles in their interior, which are organelles that store neurotransmitters for exportation -by exocytosis- or from recycling -by endocytosis-. These vesicles also protect the neurotransmitter from the enzymatic action.
Vesicles form in the cellular soma, from where they are transported to nervous terminals. Once the vesicle releases the neurotransmitter to the intercellular space, their membrane remains available in the plasmatic membrane to be reused.
The neurotransmitter concentration in the vesicle interior is related to the storage system and the transport system. There are specialized transporter proteins in the vesicle membrane that are involved with the introduction of the molecule to the organelle.
In the exposed example, transporter Trans B might be located in the vesicle membranes, and hence could be found in the cytosol of the cells.
Which of the following events contributes to the termination of a signal generated by the binding of a ligand to a receptor tyrosine kinase? Only one answer is correct
1. Phosphatases hydrolyze key phosphorylated residues.
2. Kinases hydrolyze key phosphorylated residues.
3. Kinases phosphorylate key residues.
4. The receptor tyrosine kinase dimerizes.
5. GTPase removes a phosphoryl group from GTP.
6. Phosphatases phosphorylate key residues.
Answer:
1. Phosphatases hydrolyze key phosphorylated residues.
Explanation:
Receptor Tyrosine Kinases (RTKs) are high-affinity transmembrane protein receptors that bind to a wide variety of ligands (e.g., growth factors, cytokines, hormones). These receptors (RTKs) have a transmembrane domain and therefore these proteins act as membrane receptors, as well as exhibit catalytic activity. The intracellular C terminal region of RTKs contains catalytic domains responsible for both autophosphorylation and tyrosine phosphorylation of their protein substrates. Moreover, Protein Tyrosine Phosphatase (PTPs) are critical enzymes that remove phosphate groups from tyrosine residues in different substrates (including RTKs), thereby regulating key signaling pathways such as cell proliferation, cell differentiation, and cell-cell adhesion.
A white colony growing on mannitol salt agar tests negative for coagulase and novobiocin sensitivity. This bacterium is most likely ________________
A white colony growing on mannitol salt agar tests negative for coagulase and novobiocin sensitivity. This bacterium is most likely ________________
Streptococcus pyogenes.
Staphylococcus epidermidis.
Stpahylococcus saprophyticus.
Staphylococcus aureus.
Answer:
for the first it is Staphylococcus saprophyticus. and for the second it is Streptococcus pyogenes.
Explanation:
Answer:
1. Staphylococcus aureus.
2. Staphylococcus epidermidis.
Explanation:
Which genotype would give you a wild type phenotype?
Answer:
C
Explanation:
Which of these is a benefit of fish farming?
A. It can deplete native fish populations
B. It can restock lakes depleted by recreational fishing
C. It can pollute natural bodies of water
D. It can pass diseases to native fish populations
Answer:
The answer to this would be B
Explanation:
B:It can restock lakes depleted by recreational fishing
Which of the following terms describes the distribution of a particular allele
within a population?
A. Allele dominance
B. Allele strength
C. Allele frequency
D. Allele density
Please help me
Answer:
Option : B Allele frequency...Explanation:
The answer is allelic frequency. This is also the fraction of a particular allele of a gene in the population. please marks me as brainliests..please for my answer please...All claims in science should be supported by biology
Answer:
yes
Explanation:
Because science &biology have a connection
explain what it means to view something from a frae of reference. provide an example that illustrate your explanation.
Answer:
ex. where you are standing now
a perspective that one uses to determine if an object is moving.
Explanation:
in physics, a frame of reference, or reference frame, is a perspective that one uses to determine if an object is moving. ... For example, when you see a ball roll down a street, you can tell the ball is moving because the frame of reference is the streets, whatever may be on the side of the roads, or the Earth.
wikipedia
Many of the phenotypes of DiGeorge syndrome have been traced back to one of the genes that is in the deleted region, TBX1. Some of the evidence for the important role of TBX1 in DiGeorge syndrome came from individuals who have some of the symptoms of DiGeorge syndrome without having the typical deletion. Closer examination showed that some of these individuals had SNV in the TBX1 gene. Which of the following SNVS would be most likely to create a similar phenotype to the deletion?
A. A variant in the promoter region of TBX1 that increases its expression
B. A variant in the intronic region of TBX1 that does not affect splicing. X
C. A nonsense variant near the 5' end of the TBX1 gene.
D. A silent variant near the 5' end of the TBX1 gene.
Answer:
D. A silent variant near the 5' end of the TBX1 gene.
Explanation:
TBX1 gene is wild type human being. It gives instructions for making protein called T-box 1. It plays an important role in tissue formation and organs during embryonic development.
Na + Cl2 --> NaCl if you were given 15 grams of sodium (with excess chlorine) and asked to determine the amount of NaCl that would be produced (in grams), how would you go about doing it. Be as specific as possible and include numerical values when necessary.
Answer:
The correct answer is - 38.15 gm of NaCl.
Explanation:
Write the balanced equation for this reaction of sodium (Na) and chlorine (Cl₂) to produce sodium chloride (NaCl):
2Na + Cl₂ —> 2NaCl
the mass of Na and the mass of NaCl :
Molar mass of Na = 23 g/mol
In the balanced equation = 2 × 23 = 46 g
Molar mass of NaCl = 23 + 35.5
= 58.5 g/mol
similarly in balanced equation = 2 × 58.5 = 117 g
From the balanced equation above,
46 g of Na reacted to produce 117 g of NaCl.
By converting it to 15 grams of Na.
Therefore,15 g of Na will react to produce = (15 × 117)/46 = 38.15 g of NaCl.
Thus, 38.15 g of Na
Please help!! Need the Correct Answer ASAP!!
Which statement is true?
A.Peat is a fossil fuel because rewetting it takes only 3–5 years.
B.Peat is a fossil fuel because the total time for restoration is lengthy.
C.Peat is not a fossil fuel because it has biologic origins, making it a biofuel.
D.Peat is not a fossil fuel because humans can promote the replenishment of peat.
Answer:
c) peat is not a fossil fuel because it has biologic origins, making it biofuel
Explanation:
Peat is soil/ turf
In these imprinted cells, the SNRPN transcript overlaps with another gene, called UBE3A, which is transcribed in the opposite direction. This means that the region that the RNA polymerase transcribes in these two genes actually overlaps; in some cases, overlapping transcription in opposite directions leads to transcriptional interference, meaning that collisions between the polymerases traveling in opposite directions can interfere with transcription. It is believed that this takes place in this case, meaning that the more SNRPN transcription occurs, the more this disrupts transcription of UBE3A. Based on this information as well as information about the effects of imprinting on SNRPN transcription, which of the following statements about UBE3A transcription would be true?
a. The maternal copy of UBE3A is expressed and the paternal copy is silenced.
b. The paternal copy of UBE3A is expressed and the maternal copy is silenced.
c. Both copies of UBE3A are highly expressed.
d. Both copies of UBE3A are silenced.
Answer:
a. The maternal copy of UBE3A is expressed and the paternal copy is silenced.
Explanation:
When UBE3A chromosome is in neurons, paternal allele is silent and maternal allele is expressed in process of genomic imprinting. In some cases UBE3A is expressed from both paternal and maternal chromosomes. The paternal chromosome is blue whereas maternal chromosome is magenta.
¿Qué nombres reciben los tejidos que dan
origen a los tejidos adultos de las plantas?
a. Tejidos diferenciados
b. Tejidos indiferenciados (meristemos)
c. Tejidos vegetales
Answer:
D
Explanation:
P is an autosomal dominant allele that produces a pigment, p is a recessive allele that produces no pigment. A pigmented and a non-pigmented organism mate and produce a pigmented offspring. They then mate and produce a non-pigmented offspring. What is the probability the next offspring will be pigmented
Answer:3/4
Explanation:4 possibilities, 3 dominant
If a pigmented and non-pigmented organism mate and produce a pigmented organism, which mate again and produce non-pigmented organisms, the probability that the next offspring will be pigmented is ¾ as P is the dominant, pigment-producing allele.
What are dominant alleles?The association between two genetic variants is referred to as dominant. Each gene has two alleles that an individual inherits from each parent. One allele of a gene, known as the dominant gene, will be expressed if the alleles are different. The impact of the additional allele, known as the recessive one, is concealed.
If one is in charge, the other must be recessive. Then it is referred to as recessive. A dominant gene, or dominant form of a gene, is a specific variant of a gene that expresses itself more powerfully on its own than any other version of the gene that the individual is carrying—in this example, the recessive—for a variety of reasons.
Now, it mainly refers to patterns of inheritance typically used in combination with a Punnett square, where if a person has two copies of a gene and one is shown to frequently be passed down from one generation to another, it is referred to as dominant.
According to biochemistry, what is happening in this situation is that the genetic variant may, for a variety of reasons, cause a cell to perform a very advantageous or very disadvantageous function that the other version of the gene cannot cover up or counteract.
Therefore, the probability that the next offspring will be pigmented is ¾ as P is the dominant, pigment-producing allele.
Read more about dominant alleles, here
https://brainly.com/question/2717245
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When a neuron is stimulated and sodium channels open, the process of has begun. Structures of the nervous system surrounding, but not part of the central nervous system are part of the . Two consecutive neurons communicate at a , where they physically come together. are a group of natural chemicals that reduce the perception of pain. Supporting cells of the nervous system are collectively called . When potassium channels have been open long enough to go below resting membrane potential, has occurred.
Answer:
- When a neuron is stimulated and sodium channels open, the process of depolarization has begun.
- Structures of the nervous system surrounding, but not part of the central nervous system are part of the peripheral nervous system
- Two consecutive neurons communicate at a synapse, where they physically come together.
- Endorphins are a group of natural chemicals that reduce the perception of pain.
- Supporting cells of the nervous system are collectively called neuroglia
- When potassium channels have been open long enough to go below resting membrane potential, hyperpolarization has occurred.
Explanation:
Neurons undergo depolarization in response to diverse stimuli (e.g., heat, light, electrical, chemical, etc). The depolarization occurs when sodium (Na+) ions pass through specific channels (i.e., open voltage-gated Na+ channels) into a neuron, which causes an increase in the positivity of membrane potential. On the other hand, hyperpolarization occurs when potassium (K+) channels remain open and Na+ channels reset, thereby producing an increase in negativity of membrane potential. The peripheral nervous system (PNS) is composed of the cranial nerves, spinal nerves, peripheral nerves, and neuromuscular junctions, which connect the Central nervous system (CNS) to the organs, limbs, and skin. Endorphins (e.g., serotonin) are polypeptides secreted by the pituitary gland and CNS to relieve stress and pain. Neuroglia refers to a class of neural cells that have ectodermal (e.g., astroglia, peripheral glial cells) or mesodermal (e.g., microglia) origins. Neuroglia cells are involved in diverse roles, including, among others, the formation of the blood-brain barrier, homeostatic support, provision of nutrients for neurons, structural support to nerve cells, etc.
What methods help control pollution source
Practicing conservation tillage traps contaminants from Runoff water. Practicing conservation tillage helps prevent BLANK
A. Air pollution
B. Water pollution
C. Soil erosion
predators are... a. primary producers b. primary consumers c. secondary consumers
Answer:
Primary consumers
They eat the majority of prey
what scenerio in which a population is evolving. Explain how the variants within a population was generated.
In 1985 a biologist counted 750 pine trees in a 250 hectare forest. Using similar counting techniques, the biologist counted 1,250 pine trees in 1990 and 1,500 pines in 1995.
What was the average change of the size of the population from 1985 to 1995?
What was the density of pine trees each year that they were counted?
What was the average change of density from 1985 to 1995?
Answer:
Suppose that we have a given function f(x)
The average rate of change of the function between two values x₁ and x₂ is given by:
[tex]r = \frac{f(x_2) - f(x_1)}{x_2 - x_1}[/tex]
a) We want to find the average (rate) of change on the size of population from 1985 to 1995.
We have that:
f(1985) = 750
f(1995) = 1500
Then we have:
[tex]r = \frac{1500 - 750}{1995 - 1985} = 750/10 = 75[/tex]
This means that the population of trees increases, in average, at a rate of 75 trees per year.
b) What is the density of trees each year that they were counted?
This will be equal to the quotient between the number of trees and the area.
1985: number of trees = 750 pines
area = 250 ha
Then the density is:
D(1985) = (750 pines)/(250 ha) = 3 pines/ha
So 1985, there were 3 pines per hectare.
1990: number of trees = 1250 pines
area = 250 ha
Then the density is:
D(1990) = (1250 pines)/(250 ha) = 5 pines/ha
1995: number of trees = 1500 pines
area = 250 ha
The density is:
D(1995) = (1500 pines)/(250 ha) = 6 pines/ha
3) now we want to get the average change between 1985 and 1995 in the density, this will be:
[tex]r = \frac{D(1995) - D(1885)}{1995 - 1985} = \frac{6 pines/ha - 3pines/ha}{10} = 0.3 pines/ha[/tex]
So, on average, each year the number of pines per hectare increases by 0.3
Sickle cell anemia in the United States disproportionately affects African Americans; 1 in 700 African Americans are affected by sickle cell anemia, while only 1 in 160,000 Americans of European descent are affected. The absolute risk of a newborn African American child having sickle cell anemia is ____________%, and the relative risk compared to a newborn European American child is ____________-fold
Answer:
0.0014; 0.0044
Explanation:
The absolute risk (AR) of a disease refers to the risk of developing the disease over a given time period. In this case, the absolute risk of the newborn African American child having sickle cell anemia is equal to 1 individual with the disease over 700 individuals >> AR = 1 / 700 = 0.0014. Moreover, the Relative Risk (RR) is calculated by comparing the likelihood of the absolute risk occurring between two distinct groups. In this case, the relative risk for the newborn African American having sickle cell anemia compared to a newborn European American child can be calculated by dividing the absolute risk of the newborn European American child with the measured absolute risk of the newborn African American child >> RR = 0.0000625 / 0.0014 = 0.0044.
Por qué algunas enfermedades se padecen solo una vez?
Answer:
por que a mi saber, cuando te infectas con una enfermedad viral al contagiarte y después sanar tu cuerpo crea anticuerpos que estos asu vez hacen que seas inmune a ese virus y otras veces las enfermedades son erradicadas con la vacunación.
What is the purpose of a geological time scale ?
It used to predict natural disaters throughout Earth’s history.
It is used to present the correct sequence of events in the Earth’s history.
It is used to determine the absolute dates in years for different periods.
It used to create a naming system for flora and fauna.
Answer: B. It is used to present the correct sequence of events in the Earth’s history.
Explanation: On Edge!!!! :)
Answer:bbbbb
Explanation:
qcw3ec
A particular cross gives a modified dihybrid ratio of 9:7. What phenotypic ratio would you expect in a testcross of the fully heterozygous F1 crossed with the fully recessive type
Answer:
3:1
Explanation:
Due to technical problems, you will find the complete explanation in the attached files.
