Answer:
The percentage for the homozygous dominant trait would be 25%. in the F2 generation.
Explanation:
Suppose true-breeding parents with the different alleles for the same trait are TT (dominant) and tt (recessive) than the cross of these parents will produce gametes T, T and t, t respectively.
These gametes will form offspring ultimately. Produced offspring will be TT (homozygous dominant), Tt (heterozygous dominant), Tt (heterozygous dominant) and tt (homozygous recessive).
Thus, the percentage of dominant homozygous phenotype in F2 would be 25% in respect of the dominant allele which is TT.
The percentage of the F2 generation with a dominant phenotype that would be expected to be homzygous for the allele of interest would be 33.33%
Let us assume that the allele of interest is A, the alternate form would be a.
Starting with true-breeding parents of different characteristics of the same trait:
AA x aa
Aa Aa Aa Aa
All the F1 offspring would be Aa.
Advancing the cross to F2:
Aa x Aa
AA Aa Aa aa
3/4 (AA and 2Aa) of the F2 offspring are with the dominant phenotype. However, only 1 out of the offspring is homzygous.
Thus, if the total of the F2 offspring with the dominant phenotype is 100%, the percentage with homzygous alleles can be calculated as:
1/3 x 100% = 33.33%
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After the drought of 1977, researchers hypothesized that on the Galápagos island Daphne Major, medium ground finches with large, deep beaks survived better than those with smaller beaks because they could more easily crack and eat the tough Tribulus cistoides fruits. A tourist company sets up reliable feeding stations with a variety of bird seeds (different types and sizes) so that tourists can get a better look at the finches. Which of these events is now most likely to occur to finch beaks on this island?A) evolution of yet larger, deeper beaks over time, until all birds have relatively large, deep beaksB) evolution of smaller, pointier beaks over time, until all birds have relatively small, pointy beaksC) increased variation in beak size and shape over timeD) no change in beak size and shape over time
With the presence of reliable feeding stations providing various seeds, there is likely to be increased variation in finch beak size and shape on Daphne Major, leading to a more diverse finch population.
Explanation:After the introduction of reliable feeding stations by a tourist company on the Galápagos island of Daphne Major, it is most likely that finch beaks would show increased variation in size and shape over time. This scenario would occur because the artificial food source removes the need for specialized beak types that evolved due to natural selection pressures. With a variety of seeds available, there is less advantage to having a beak specialized for a specific seed type. This is in contrast to the situation that led to the evolution of larger beaks following the 1977 drought, where the natural food scarcity meant that finches with larger beaks were more likely to survive. Now, with the removal of this selective pressure, finches with a wider range of beak sizes and shapes can thrive and reproduce, potentially leading to a more diverse finch population.
What is the second arterial branch of the aortic arch?
Answer: The Carotid Artery
Explanation:
Supplies Blood to the left side of the Head of the neck
(BRAINLIEST ANSWER GUARANTEED)Taste preferences in humans are the result of the following except:
A. Cultures
B. Body Chemistry
C.Set point
D.Environmental factors
Answer:
A. Cultures
Explanation:
In the middle east, spicyness is a flavor that all love and need. Up north in germany, and etc. Spicyness is not loved and is avoidable
Answer:
The correct answer is option C. Set point
Explanation:
Hello!
Let's solve this!
Let's analyze each of the options:
Cultures: cultures help the preferences of flavors, since the population since they begin to feed, begin to taste the flavors of cultures.
Body Chemistry: the chemistry of the body limits what flavors we like and which do not.
Set point: this option does not limit taste preferences.
Environmental factors: limits preferences because some foods depending on the area where they live are consumed or not, for example.
After the analysis, we conclude that the correct answer is option C. Set point
To maximize the number of thymine dimer mutations following UV exposure, should you keep human cells in tissue culture in the dark, in the light, or does it matter at all?
Answer:
It doesn't matter at all.
Explanation:
Thymine dimers are corrected by DNA photolyases. The chromophore of these enzymes absorbs the energy of light to fix the dimers. However, the placental mammals such as human do not have the DNA photolyases to correct the dimers formed by exposure to UV radiations.
Hence, keeping the UV exposed cells in light or dark would not have any effect on the number of thymine dimers produced by UV exposure of a human cell.
Histamine increases blood flow and vascular permeability. This would account for which of the following changes that occur during inflammation? (redness of the inflamed tissue, swelling of the inflamed tissue, heat of the inflamed tissue, the localization of proteins and cells necessary for the body defense, all of the above)
Answer:
All of the above.
Explanation:
Inflammation may be defined as the immune response generated triggered by the affected tissue. The main purpose of inflammation is the elimination of injurious agent, removes the damaged tissue and helps in healing of the tissue.
Various changes occur during the inflammation process. Pain in the affected tissue (dolor), heating in the tissue (calor), redness in the inflamed tissue (rubor), swelling of the tissue (tumor). Proteins and cells localization is necessary for the body defense during inflammation.
Thus, the correct answer is (5).
How does the egg of a flower become fertilized? 1 answer, not multiple choice.
as soon as the pollen reaches the stigma
after the pollen grain descends down the style
when the pollen tube grows into the ovule
when the seed germinates
Answer:
as soon as the pollen reaches the stigma
Explanation:
When pollen lands on stigma, it germinates and gives rise to a pollen tube that passes through the style and reaches the ovary of a pistil
Answer:
when the pollen tube grows into the ovule
Explanation:
Fertilization in plants occurs after pollination. Pollination does not always guarantee fertilization. Whether fertilization will occur or not totally depends upon the later stages which occur after pollination.
The following stages give a better idea of how egg of flower is fertilized:
1) Pollination: A soon as a pollen reaches the stigma pollination is said to occur.
2) Germination: When pollen comes in contact with stigma, it absorbs some chemicals like inositol, Ca²⁺, boran, brassinosteroids and water from the stigma as a result of which pollen starts to increase in size to form pollen tube. The pollen tube begins to grow which is also known as germination.
3) Penetration of ovule & 4) Fertilization: The growing pollen tube travels through style to reach ovary which has ovule inside it. The pollen contains 2 haploid nuclei while ovule contains 3 haploid nuclei. One of the nuclei in ovule is in the egg cell so it is haploid while 2 nuclei are inside central cell. When the pollen tube keeps on increasing in size, it ultimately penetrates the ovule and one of the nuclei of pollen tube fuses with egg cell and the process is known as fertilization.The other nuclei of pollen tube fuses with central cell which ultimately has 3 nuclei and the process is known as triple fusion. These two processes i.e. fertilization & triple fusion are collectively known as double fertilization.
When Dr. Emory looks at slides of blood samples, he sees a rich and diverse world of cellular life instead of small dots on a slide. In using his years of experience looking at slides, what is Dr. Emory is using?
Answer: He is using Top Down Processing
Explanation:
Top Down Processing is related to how our brains use information that was already in them.
RNAi
a. is any chemical that inhibits transcription.
b. uses short pieces of double-stranded RNA to direct the degradation of specific RNA transcripts.
c. is the form of mRNA that initiates translation in most pathogenic bacteria.
d. is a mechanism of genetic regulation found in all prokaryotes.
e. uses short pieces of single-stranded RNA to direct the degradation of specific RNA transcripts
Cns nerve fibers regenerate because of the actions of schwann cells. True or False
Answer:
True
Explanation:
Nerve fibers can regenerate because of the actions of schwann cells.
The application of evolutionary principles to the study of human variation: a. helped replace earlier views based solely on observed phenotypes. b. allowed scientists to divide the human species precisely into well-defined races. c. reinforced traditional views of races as fixed biological entities that do not change. d. has been of little value for understanding human variation. e. allowed scientists to ignore the adaptive significance of most traits.
Answer: Helped replace earlier views based solely on observed phenotypes.
Explanation: Historically, physical differences such as skin color were used as the basis of racial classification due to differences in skin pigment being so noticeable.
This thinking can be traced back to before World War II, where most studies of human variation were solely based on the visual phenotypic variations. It was only in the second half of the twentieth century that we started looking at genetics and realized that we could not trace human evolution based on visual phenotypes observed, but rather genetic heritages.
Applying evolutionary principles to the study of human variation has replaced views based solely on observed phenotypes and advanced our understanding of genetic diversity. The concept of 'race' as a fixed biological entity has been debunked, with more genetic variation existing within 'racial' categories than between them. Therefore, this application has not prompted a precise division of the human species into races or ignored the adaptive significance of traits.
Explanation:The application of evolutionary principles to the study of human variation has indeed helped replace earlier views based solely on observed phenotypes (option a is correct). This is because contemporary biological anthropologists use an evolutionary perspective to understand how living organisms, including humans, thrive in different environments. Central to this is the idea of natural selection, which suggests that those organisms with characteristics better suited to their environment are more likely to survive and proliferate. This approach has facilitated a greater understanding of human genetic diversity.
However, the concept of 'race', traditionally seen as a fixed biological entity, has been largely debunked by this approach. Most scientists now agree that there is actually more genetic variation within a given 'racial' category than there is between different 'racial' categories (options b and c are incorrect). Therefore, the application of evolution to the study of human variation has not allowed scientists to divide the human species precisely into well-defined races, nor has it reinforced traditional views of races as unchanging.
Far from being of little value or allowing scientists to ignore the adaptive significance of traits (options d and e are incorrect), the evolutionary perspective has been crucial in advancing our understanding of human variation, adaptation and evolution.
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Plants from the genus Solanum include such common vegetables as potatoes and eggplants. The many species include some plants native to tropical West Africa as well as closely related species native to tropical South America. What might you reasonably conclude?
Answer:
The plants from West Africa and South America were once together as one population.
Explanation:
This could be used as a source of proof for continental drift. When West Africa and South America were connected as one continent, known as Pangea, these two now existing plants were one species of plant in the genus Solanum. As the continents drifted apart the plants evolved separately on each continent according to their different environments. Now they are just closely related species as they have evolved more differences.
One of the reasons why statins are effective in reducing the risk of cardiovascular disease is ______.
a. they increase the transport of cholesterol away from the liver
b. they reduce the protein content of LDLs
c. they decrease the incidence of cholesterol deposition in arterial walls
d. All of the listed responses are correct.
Answer: c. they decrease the incidence of cholesterol deposition in arterial walls.
Explanation:
The statin is a drug which block the action of the liver enzyme which controls the production of the cholesterol. The cholesterol is a biomolecule which aggregate inside the blood vessels such as arteries may lead to arteriosclerosis. This condition will lead to increase in blood pressure which may lead to the condition of hypertension or heart attack.
By lowering the levels of the cholesterol in the arteries the statins can reduce the risk of cardiovascular disease.
Answer:
The correct answer will be option D.
Explanation:
Statins are a class of drug provided in the medication to treat cardiovascular disease.
Statins act by reducing the amount of bad cholesterol called low-density lipoprotein (LDL) from blood, preventing the formation of cholesterol from the liver by blocking the enzyme and pathway of cholestrol synthesis and the degradation of the deposited cholestrol form the arterial walls which make the arteries narrow.
Thus, option D is the correct answer.
Which of the following is true for identical twins?
A. They are attached until just before birth.
B. They can have different genes.
C. They can have different fathers.
D. They can express the same genes differently.
Answer:
the answer is d
Explanation:
A "motor homunculus" can be visualized as an overlay on the precentral gyrus. The reason why the facial region of this homunculus covers such a large surface area is because
(A) our ears are large for hearing.
(B) our eyes are large for seeing.
(C) we have very expressive faces.
(D) we have very sensitive lips.
Answer: the correct answer is (C) we have very expressive faces.
Explanation:
A cortical homunculus is a distorted representation of the human body based on a "neurological map" of the areas and proportions of the human brain.
The correct option is ( c) we have very expressive faces.
The homunculus in the sensory cortex is almost invisible to humans. The face and hands are drawn larger than the torso, arms, and legs. This is because the brain maps each sensory receptor to the cortex rather than considering the area of the body where the sensor is located. Why is the motor homunculus significant?The motor homunculus represents a map of the brain region dedicated to the motor processing of the various anatomical divisions of the body. The primary motor cortex is located in the precentral gyrus and processes signals coming from the premotor cortex of the frontal lobe.Learn more about https://brainly.com/question/13962137 here
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The drug AZT Multiple Choice inhibits the production of HIV proteins. is incorporated into DNA by reverse transcriptase, making it impossible to add additional nucleotides. binds to human cell receptors, thereby blocking HIV's access to them. inhibits the enzyme protease.
Answer: Option A
Explanation:
The drug AZT belongs to the group of drugs that is used in case of HIV. These class of drugs are known as Nucleoside analogues.
This drug interferes with the enzyme reverse trsncriptase which is used by the cells affected from HIV for the production of new viruses.
So, this drug reduces the activity of reverse transcriptase which reduces the chances of the cells to divide further to new HIV infected cell.
Hence, the correct answer is option A
Each skeletal muscle fiber is controlled by a neuron at a single ___________.
a.neuromuscular junction
b.sarcomere
c.synaptic cleft
d.transverse tubule
e.synaptic knob
Answer:
a. neuromuscular junction
Explanation:
Each skeletal muscle fiber is controlled by a neuron at a single neuromuscular junction.
A single cylindrical muscle cell makes up each skeletal muscle fiber. A single skeletal muscle might consist of hundreds or even thousands of muscle fibers that have been bundled together and covered in connective tissue. The epimysium, a sheath of connective tissue, encases each muscle.
A neuron at a single Location controls every skeletal muscle fiber.
Neuromuscular connection is the answer.
Skeletal muscle is controlled by what kind of neuron?
a motor neuron in alpha
Muscle contractions that result in movement are triggered by alpha motor neurons, also known as lower motor neurons, which innervate skeletal muscle. At a synaptic junction known as the neuromuscular junction, motor neurons release the neurotransmitter acetylcholine.
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How many times does a cell divide during meiosis
Answer:
twice
Explanation:
divides to form two daughter cells
Answer:
twice
Explanation:
I just took a test that had a video and it said twice
{Hope this helps} : )
Anson is 75 years old and has recently been experiencing a change in his personality. He is acting more impulsively and does not seem to care about his loved ones, to whom he has always been very devoted. While he was always frugal with his money, he is now gambling frequently and losing much of his retirement savings. He does not seem to be experiencing any physical symptoms. From which is Anson most likely suffering?
Answer: anxiety disorder
Explanation:when people get older there is always a creeping fear of dying. As a coping mechanism Anson resorts to gambling and violence inorder to copy with his fears and escape reality.
Final answer:
Anson appears to be experiencing personality changes indicative of a neurological or psychiatric condition, such as dementia. Medical evaluation, including cognitive tests and brain imaging, is critical for diagnosis and management.
Explanation:
Anson's sudden change in personality and the development of impulsive behaviors, such as compulsive gambling and disregard for his loved ones, could be symptomatic of a neurological or psychiatric condition. Such symptoms are not typical aspects of normal aging, and they may indicate the onset of a form of dementia, a frontal lobe disorder, or other mental health issues.
It's important for Anson to receive medical attention. A health professional would likely assess his cognitive functioning through various tests, conduct a physical examination, and possibly order brain imaging studies to identify any structural changes. Personality changes in elderly individuals, especially those involving impulsive behavior and poor money management, are concerning and should not be dismissed as part of normal aging.
The neuromuscular junction is a well-studied example of a chemical synapse. Which of the following statements describes a critical event that occurs at the neuromuscular junction?
a) Acetylcholine is released by axon terminals of the motor neuron.
b) When the action potential reaches the end of the axon terminal, voltage-gated sodium channels open and sodium ions diffuse into the terminal.
c) Acetylcholine binds to its receptor in the junctional folds of the sarcolemma. Its receptor is linked to a G protein.
d) Acetylcholine is released and moves across the synaptic cleft bound to a transport protein.
Answer:
A- Acetylcholine is released by axon terminals of the motor neuron.
Explanation:
The general mechanism of muscle contraction can be explained as follows:
a) The action potential which is generated, travels along the motor nerve to its ends on muscle fiber (or motor end plate) at the neuro-muscular junction.
b) The nerve endings then secrete small amounts of neurotransmitter called acetylcholine.
c) The actylecholine binds to the receptors on the membrane of muscle fiber and opens the voltage gated sodium channels.
d) Opening of these channels leads to flow of large quantities of sodium ions into the muscle fiber which ultimately results in initiation of action potential in muscle fiber.
e) This action potential depolarizes the fiber including the T-tubules, triggering the release of calcium ions from sarcoplasmic reticulum.
f) The calcium ions thus released initiated the process of muscle contraction.
Lysogenic bacteriophages contribute to bacterial virulence because bacteriophages kill human cells. carry plasmids. kill the bacteria, causing release of endotoxins. produce toxins. give new gene sequences to the host bacteria.
Answer: give new gene sequences to the host bacteria.
Explanation:
Bacteriophages are viruses that infect bacteria. Viruses are the most numerous organisms on earth and play functions in the biotic component of virtually every ecosystem. They are distinct biological entities and the main feature of this group is the dependence on specific hosts for reproduction, hence known as obligate intracellular parasites. In the lysogenic cycle, phage nucleic acid recombines with that of the bacteria forming a prophage and replicates in the host cell from one generation to another without cell lysis. By doing this, the bacteriophages give new gene sequences to the host bacteria, contributing to bacterial virulence.
Imagine that you are performing a cross involving seed color in garden pea plants. What traits would you expect to observe in the F1 offspring if you cross true-breeding parents with green seeds and yellow seeds?
(A) Yellow seed color is dominant over green.
(B) only yellow-green seeds
(C) green seeds:yellow seeds 1:3
(D) yellow seeds:green 1 : 1
(E) only yellow seeds
Answer:
Option E, only yellow seeds
Explanation:
True breeding means when the genotype of one parent consists of two identical alleles.
Let allele for green color seed be represented by "g" and yellow color seed be represented by "G"
In this scenario,
Genotype of true-breeding parents with green seeds is "gg"
Genotype of true-breeding parents with yellow seeds is "GG"
It is given that Yellow seed color is dominant over green
The punnet square representing this cross would be
G G
g Gg Gg
g Gg Gg
All the offspring are heterogyzous yellow seeded plants
Thus, option E is correct
If calcium levels are low, camp activity increases which leads to synthesis and release of parathyroid hormone. camp acts as a(n)
Answer:
Second messenger
Explanation:
When a hormone binds on its cell receptor on the cell, it initiates a cascade of membrane protein changes that begin a secondary signaling process inside of the cell. The cAMP is a secondary messenger that is involved in intracellular signaling. In this case, it causes the cell to produce more PTH in response to low calcium levels.
Are the reactions serving as flux control points conside?
Answer:
Explanation:
Yup
Which of the following is the correct sequence of development from zygote to embryo?
cleavage, gastrula, morula, blastocyst
blastocyst, cleavage, gastrula, morula
cleavage, blastocyst, morula, gastrula
cleavage, morula, blastocyst, gastrula
Answer:
Cleavage, morula, blastocyst, gastrula
Explanation:
The zygote is formed after fertilization of sperm and ovum. Then the zygote undergoes a repeated cell division to form a number of cells. These tiny cells formed by mitotic cell division but present inside the zygote. It forms 2 cells then 2 cells, then 8 cells and so on. After forming the number of cells the zygote has a number of tiny cells. This stage is called morula and the tiny cells are called morulae. Then these cells migrate towards the periphery of the morula and creating a central space called blastocoel. This hollow ball structure is known as the blastocyst. After this blastocyst stage, the cells migrate to form 3 layers such as endoderm, mesoderm, ectoderm. From this layer different organs are formed. This 3 layered stage is known as gastrula. Thus the zygote development starts from cleavage, morula, blastula, and gastrula.
The correct developmental order from a zygote to an embryo is cleavage, morula, blastocyst, and gastrula, which involves cell division and restructuring into layers.
Explanation:The correct sequence of development from a zygote to an embryo is as follows: cleavage, morula, blastocyst, gastrula. Initially, the zygote undergoes rapid cell division known as cleavage, forming smaller cells called blastomeres. This process leads to the formation of a morula, which is a solid ball of cells.
Following this, the structure develops into a blastocyst, which has a distinct inner cell mass and is surrounded by an outer layer of cells.
Finally, gastrulation occurs, where the blastocyst reorganizes into a gastrula with different layers that will develop into various tissues and organs of the embryo.
During replication, the function of the enzyme DNA polymerase is to
a. send messages
b. locate replication sites.
c. bind nucleotides together.
Answer:
b. locate replication sites.
Explanation:
During replication, the function of the enzyme DNA polymerase is to locate replication sites.
What foods are good sources of multiple micronutrients
Answer:
Calcium - milk, yogurt, spinach, and sardines.
Vitamin B12 - beef, fish, cheese, and eggs.
Zinc - beef, cashews, garbanzo beans, and turkey.
Potassium - bananas, spinach, potatoes, and apricots.
Vitamin C - oranges, peppers, broccoli, and bananas.
Explanation:
vitamin B6, vitamin C, vitamin E, magnesium, and zinc—play roles in maintaining immune function, and supplements containing them are often sold as immune boosters in doses that greatly exceed the recommended daily allowance
Which process drives darwin’s theory of evolution?
Answer:
Natural selection
Explanation:
I did some research and got that for an answer
Answer:
PLEASE GIVE BRAINLIEST AND HAVE A NICE DAY
The process that drives Darwin's theory of evolution is natural selection
In mountain areas, when large amounts of rock fragments move downslope of their own weight, they are called ________.
Answer:
Avalanche
Explanation:
They mostly happen in mountainous regions where there is snow/ice and rocks. The ice underneath the boulders thaws momentarily due to the pressure of the rocks and ice above hence acting as a lubricant for the sliding down of the rocks down the mountain. Avalanches can be triggered by earthquakes, explosions, and etcetera.
Which of the following statements is true? (a) Extracellular signal molecules that are hydrophilic must bind to a cell-surface receptor so as to signal a target cell to change its behavior. (b) To function, all extracellular signal molecules must be transported by their receptor across the plasma membrane into the cytosol. (c) A cell-surface receptor capable of binding only one type of signal molecule can mediate only one kind of cell response. (d) Any foreign substance that binds to a receptor for a normal signal molecule will always induce the same response that is produced by that signal molecule on the same cell type.
Answer:
Its option 'A'.
Explanation:
extracellular signal molecules that are hydrophilic must bind to a cell-surface receptor so as to signal a target cell to change its behavior.
For Example:
Acetylcholine acts at a GPCR on heart muscle to make the heart beat more slowly.
The following statements is true - (a) Extracellular signal molecules that are hydrophilic must bind to a cell-surface receptor so as to signal a target cell to change its behavior
Extracellular signals:Signals that originate from outside a cell
physical agents like mechanical pressure, voltage, temperature, light, or chemical
These are hydrophobic signals that can not cross the cell membraneBind to the specific signal receptor to target cell in order to initiate changes in cell function.For instance, neurotransmitters are hydrophilic molecules that bind to cell surface receptors.As neurotransmitters are hydrophilic molecules, they are unable to cross the plasma membrane of their target cells.Learn more:
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_____ gave Stanford nursery schoolchildren a choice between a marshmallow now and two later. He found that the children who were able to wait had higher completion rates and incomes and were less likely to experience addiction as an adult. He also found that this tendency to wait or not persisted even 40 years later.
Answer: the correct answer is Walter Mischel.
Explanation: Walter Mischel was an important Austrian psychologist that studied personality.