Where in the lymph node do the t cells first encounter antigens presented by dendritic cells?

Answer: Eosinophils

Explanation:

Eosinophils can be defined as a type of white blood cell whose number increases in the blood when there is any infection in the body or at the time of any allergic reaction or even in case of cancer.

Presence of more than 500 eosinophils per mL of blood is normal in an adult but more than 1500 eosinophils per mL of blood shows infection and if lasts for several months then the condition will be hypereosinophils.

So, the correct answer is eosinophiles.

Answer:

Purpose: to impart better night vision to nocturnal animals by increasing the available light for photoreceptors.

It is called "tapetum lucidum".

Explanation:

The reflective material in the choroid coat of some nocturnal vertebrates is called "tapetum lucidum". Its function is to improve the night vision of nocturnal animals. The tapetum lucidum serves to reflect the dim light available in the night. The reflected light re-stimulates the photoreceptor cells present in the retina. This increases the available light for night vision.

Tapetum lucidum makes the eyes of nocturnal mammals to shine at night.

Final answer:

The reflective material in the choroid coat, known as the tapetum lucidum, reduces internal reflection of light, providing a clearer image and is especially beneficial for night vision in nocturnal animals. Humans, on the other hand, have melanin in the choroid coat to absorb light and prevent internal reflection.

Explanation:

Purpose of Reflective Material in the Choroid Coat

The purpose of the reflective material found in the choroid coat is to reduce reflection of stray light within the eye, enhancing visual acuity by preventing internal glare and light scattering. This reflective material, known as the tapetum lucidum, is particularly significant in nocturnal animals as it amplifies light to improve night vision. The tapetum lucidum achieves this by reflecting visible light back through the retina, thus giving animals with this layer better ability to see in low light conditions. The reflective effect of the tapetum lucidum also causes the eye-shine observed when light is shone into the eyes of certain animals at night.

In humans, however, this feature is absent as the human choroid coat is pigmented with melanin that serves to absorb light rather than reflect it. The melanin within the choroid coat ensures that any light entering the eye does not reflect internally, which would otherwise cause blurring and decrease in the sharpness of vision.

Answer:

Frequency of p [tex]= 0.684[/tex]

Frequency of p [tex]= 0.316[/tex]

Number of individuals with homozygous dominant (AA) [tex]= 47[/tex]

Number of individuals with heterozygous (Aa)[tex]= 43[/tex]

Number of individuals with homozygous recessive (aa) [tex]= 10[/tex]

Explanation:

Out of 100 people, 10 have albino skin (aa)

So, the frequency of homozygous recessive individuals [tex](q^{2})[/tex] is [tex]\frac{10}{100} = 0.1[/tex]

Now, q will be

[tex]= \sqrt{q^{2} } = \sqrt{0.1} \\= 0.316[/tex]

As per Hardy Weinberg's equation -

[tex]p + q = 1[/tex]

Substituting the value of q in above equation, we get -

[tex]p + 0.316 = 1p = 1 -0.316\\p = 0.684[/tex]

Now the frequency of homozygous dominant (AA) will be

[tex]p^{2} = 0.684^{2} \\= 0.467[/tex]

Hence, out of 100 people [tex]0.467 * 100 = 46.7 or 47[/tex] people are homozygous dominant (AA)

Like wise out of 100 people [tex]0.1 * 100 = 10 [/tex] people are homozygous recessive (aa)

As per As per Hardy Weinberg's equation-

[tex]p^{2} + q^{2} + 2pq = 1\\[/tex]

Substituting the values in above equation, we get -

[tex]0.467 + 0.316 + 2pq = 1\\2pq = 1 -( 0.467+ 0.1)\\2pq = 0.433[/tex]

So, out of 100 people [tex]0.433 * 100 = 43.3 or 43[/tex] people are heterozygous (Aa)

K... lets break this down... LOL Verified answers be like  

its coronal!

Answer:

autonomic

Explanation:

Peripheral nervous system is divided into somatic nervous system and autonomic nervous system .

Sympathetic and parasympathetic nervous system are the divisions of autonomic nervous system. These divisions of autonomic nervous system works in antagonistic manner. Autonomic nervous system regulates the antagonistic control of the efferent output by the divisions of sympathetic and parasympathetic nervous system.

Thus, the correct answer is option (C).

Answer:

epiphyseal line indicates..

Explanation:

that the growth cycle has completed in this individual...the answer is A.

The presence of an epiphyseal line in a bone indicates that the growth, or lengthening, of that bone has ended. It occurs as a result of the hardening of the growth plate once the bone has reached its full length.

The presence of an epiphyseal line in a bone indicates that the epiphyseal growth, or lengthening, of that bone has ended. The epiphyseal line is a remnant of the epiphyseal plate, also known as the growth plate, which is an area of growing tissue near the ends of the long bones in children and adolescents. Once the bone has completed its growth in length, the growth plate hardens and becomes the epiphyseal line.

So, in the context of the options given, the correct answer would be 'a. Epiphyseal growth has ended'. This occurs when the individual reaches physical maturity, and thus, no more bone growth in length would occur from that point onwards.

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Answer:

Option (B).

Explanation:

Peyer's patches are the small masses of aggregated small lymphatic tissues and provide immunity to an organism. Peyer patches are discovered by the scientiest Johannan Cornard Peyer.

Peyer's patches are located in the ileum region of small intestine. These patches control the growth of harmful bacteria and regulates the growth of intestine bacteria. T

Thus, the correct answer is option (B).

Peyer's patches are found in the ileum of the small intestine, specifically concentrated in the distal ileum, and are important for immune function in the gut.

Peyer's patches, which are part of the mucosa-associated lymphoid tissue (MALT), are found in the ileum of the small intestine. These structures are lymphoid nodules that extend from the mucosa layer into the submucosa layer and play a crucial role in the body's immune response by sampling and responding to antigens present in the intestinal lumen. They are most prominent in the distal ileum and contain B lymphocytes in their germinal centers, along with T lymphocytes in the zones between follicles. Peyer's patches are covered by follicle-associated epithelium, which contains fewer goblet cells and includes specialized cells called microfold or M cells, which facilitate the uptake and transport of antigens.

Answer:

c) double dissociation memory

Explanation:

The hippocampus is necessary for double dissociation memory, connecting memories of objects through space and time.

Final answer:

The hippocampus is essential for relational memory, allowing for the connection of memories across time and space, different than object recognition memory, double dissociation memory, or classical conditioning. So the correct option is a.

Explanation:

The hippocampus is necessary for relational memory, which is the ability to connect memories of objects through space and time. Relational memory enables us to understand how different pieces of information are related to one another, such as recognizing an environment and remembering the events that happened there. While the hippocampus is involved with various forms of memory, including declarative and episodic memory as well as recognition memory, learning and recall that involve linking together stimuli, such as those we experience over time and space, are crucially dependent on the hippocampus. This distinguishes relational memory from other types like object recognition memory (which involves recognizing objects but not necessarily placing them in spatial or temporal context), double dissociation memory (a concept that deals with how different parts of the brain are specialized for different functions), and classical conditioning (a form of learning involving stimuli, which primarily involves the cerebellum).

Answer:

I believe that the answer is B. fatty fish.

Explanation:

Fatty fish has been proven in numerous studies to contain a lot of omega-3 fatty acids. This is why the fish oils are often prescribed in gels. Omega-3 fatty acids contain essential nutrients that help prevent and manage heart disease. It decreases the chance of cardiac deaths. It also can help your brain and can treat depression and anxiety. Omega-3 fatty acids can even help improve your vision. Hope this helps!

Answer:

The answer is Fatty Fish.

Explanation:

Light passes through the cornea, aqueous humor and when it passes through the lens, it is converged. The light passes through the vitreous humor and focuses on the fovea region of the retina. The Retina has photopigment (cones and rods). They perceive light and convert it to electrical impulses that are carried by the optical never to the brain. The iris controls the amount of light that enters the eye.

Answer:

I believe it's size

Muscles are defined as the organizational level that is formed by the aggregate of the tissues. The number of fibers is not the characteristic of name muscles. Thus, option d is correct.

Muscles have been part of the level of organization that is aggregates of the soft tissues that together make the organs of the organisms. Various muscles are involved in various functions. The skeletal, smooth and cardiac are the main muscles.

The muscles are named in three major ways that include the shape and size of the muscles compared to other muscles of the body. Like the cardiac muscles are unique to the circulatory system.

It can also be named by the virtue of its location and point of attachment which includes skeletal muscles that are attached to various ligaments. They can also be named based on their origin and action like the heart muscles.

The number of fibers is not a characteristic property to define and name the muscles of the body as fibers are the integral part that varies in number and cannot be accounted for in the naming.

Therefore, option d. a number of fibers are not used to name, muscles.

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Answer:

Explanation:

Osteoporosis is a disease of bones. It occurs when bones loose density and structure of bone becomes porous. This condition leads to weaking of bones and the bones may break.

Causes : The low calcium diet in food, estrogen deficiency in women, Vitamin D deficiency and high levels of thyroid hormone secretion, too much alcohol consumption, smoking and medical condition of cystic fibrosis also result in bone weakening are responsible causes of osteoporosis.

Prevention : It can be prevented by medication, weight bearing physical exercises which can prevent loss of bones and provide strength, healthy diet with calcium and Vitamin D supplements.

Answer:

Increased sympathetic stimulation....

The pressure of the blood on the walls of the arteries is called arterial pressure. Increased sympathetic stimulation does not increase arterial blood pressure.

Sympathetic stimulation is the ability of the vessels to resist high blood pressure by the stimulation of the sympathetic nerves. This is essential for the prevention of over perfusion and dysfunction.

The sympathetic stimulation can raise the heart rate, constrict blood vessels, increase blood pressure, decreases large intestines movement and dilate the pupil of the eye.

When the sympathetic stimulation is increased then the blood pressure on the walls of the arteries remains unaffected and does not increase.

Therefore, option d. increased sympathetic stimulation does not increase arterial blood pressure.

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Answer:

GABA

Explanation:

Purkinje neurons are located in the cerebellar cortex of an organism. These neurons receive impulse from the granule cells. These neurons were discovered by the czech scientiest Purkyne.

GABA ( Gamma amino butyric acid) is the only transmitter used by the purkinje cells for signalling. The GABA neurotransmitter blocks the neurotransmission and shows the inhibitory actions on cells.

Thus, the correct answer is option (D).

Answer:

d. They always invade the human body from the external environment

Explanation:

Antigens are the molecules that have the ability to stimulate immune response and are mostly protein in nature. However, an antigen may be self or non-self molecule.

This means that antigen may enter the human body from the external environment (the non-self antigen) or any molecule present inside the body may serve as antigen (self-antigen). Self-antigens are responsible for autoimmune disorders.

Answer:

Vagus nerve.

Explanation:

Vagus nerve is the tenth cranial nerve and largest among all the cranial nerves. This nerve transmits information to or from the surface of brain to the tissue or organ.

Vagus nerve is responsible for regulation of various functions like sweating, blood pressure, digestion, peristalsis and cardiac rhythmicity. Cranial nerve innervates in different system of body like digestion, blood pressure and cardiac rhythm.  

A single muscle cell is known as a muscle fiber, which contains hundreds to thousands of myofibrils. The muscle fiber is encased in a plasma membrane called the sarcolemma and contains cytoplasm or sarcoplasm. Sarcomeres within myofibrils facilitate muscle contraction.

A single muscle cell is called a muscle fiber. These are the individual cells that make up skeletal muscle tissue. Each muscle fiber is surrounded by a plasma membrane known as the sarcolemma, with a cytoplasm called the sarcoplasm. Muscle fibers are incredibly large cells, containing hundreds to thousands of myofibrils. Myofibrils are the long cylindrical structures that run parallel to the muscle fiber and give the muscle its striated appearance.

Within each muscle fiber, myofibrils are organized into units called sarcomeres, which is the smallest contractile portion of muscle tissue. The repeating units of sarcomeres along a myofibril are what lead to muscle contraction. Muscle fibers consist of myofilaments composed of the proteins actin and myosin organized in sarcomeres, allowing for the muscle contraction mechanism that is vital for movement.

Answer:

The skeletal system of beings, especially human beings, is a pretty simple, and yet complex one. When talking about bone tissue, and bone structure, we have, in essence three main cell types which actually form it, while inside bones we have the appearance of other types of cells which are not directly related to the bone itself.

These three types of bone-related cells, are: the osteoblast, the osteocytes and the osteoclasts.

The osteoblast is essentially the basic cell unit of bone tissue and its orgin, like osteocytes, are the mesenchymal progenitor cells. The osteocyte, is another type of osteoblast but has the particular characteristic that it is start shaped, and it is immovable and trapped within the web created in a formed and calcified bone. They do not divide, they do not change, but remain during their period of life until they die. The third type is the osteoclast, the cell that is responsible for the reformation of bone tissue by breaking and reabsorbing bone tissue. An important fact about these cells is that through the process of reorption, they ensure the correct blood levels of calcium.

Answer:

c. RrMm x  RrMm

Explanation:

A dihybrid genotype is the one that is heterozygous for two genes. Hence, a dihybrid cross is a cross between two individuals that are hybrid for alleles of two different loci.

Among the given examples, the cross RrMm x RrMm is a dihybrid cross. Here, both given genotypes are heterozygous or hybrid for two loci (both genotypes have one dominant and one recessive allele for both the genes under study, R and r; M and m).

This cross explains the inheritance of two loci or two genetic traits. Hence, it is an example of dihybrid cross.

Answer:

-RNA molecule.

Explanation:

Reverse transcriptase or RT can be defined as an enzyme that synthesizes cDNA (complementary DNA) molecules by using RNA molecule as template. This process is known as reverse transcription.

Reverse transcriptase enzyme is found in many RNA viruses, prokaryotes and eukaryotes. Telomerase in an example of reverse transcriptase, which is found in eukaryotes and replicates ends of linear chromosomes.

Thus, the correct answer is 'RNA.'

Answer:

John is clearly going through a lot. There's many things that could of cause drinking at a young age. To really know the cause of the heavy use, we need to go back when he was 12. I don't believe this was really caused by genetics.  although the dad and grandfather was drinking, this is a learnt behavior. Children tend to follow a parent's path in life. being around drinking as a kid, can have deep impacts on a child's development. this could have of all started when his dad left an open beer out one day. This is the same with children who is around smoking parents. Although they might say "Don't ever smoke", the children is gonna end up smoking if something doesn't stop. When john's father died, it could of had another really serious impact on him. Plus, we dont know if there was any abusive behaviors going on. I dont think that drinking is the main issue in this case. Im not a psychologist, but i notice early signs of depression and possibly death. I do notice signs of an anxiety disorder also. I feel as if john's mother is adding on to the problem, by not supporting him and being there for him.

Explanation:

The causes of John's behavior relate to genetics, early childhood experiences, cognition/thought distortion, and wider society.

The causes of John's behavior can be attributed to a combination of factors. Genetics plays a role, as both his father and grandfather were diagnosed with alcohol use disorder. Early childhood experiences, such as growing up in a family where alcohol misuse and negative labels were present, can also contribute. Additionally, problems with cognition and thought distortion, particularly related to anxiety, may drive John to drink excessively. Lastly, wider society and the stigma associated with being the 'black sheep' of the family may affect John's self-identity and exacerbate his behavior.

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The answer is D, digestive.

Hello There!

The muscle that turns the palm up is called the "Supinator"

The supinator muscle is in the forearm.

Answer:

The two kingdoms of prokaryotes are kingdom archaea and eubacteria. Eubacteria

Eubacteria are the disease causing bacteria. They are more complex than archaea bacteria and are found almost everywhere. They are important to the ecosystem because they help with decomposition of materials. The defining feature of archaea bateria is its living environment. They thrive in environments with EXTREME temperatures. They can live in very hot or very cold areas.

Originally, prokaryotes were classified only in kingdom monera but new discoveries and technology led to the split.

Answer: neurotransmitters

Explanation:

The neurotransmitters are the chemicals which are released at the synaptic cleft or synapse present between the two neurons. These are the chemical messengers which carries the signals from one neuron to other and helps in transmission of the information. The chemical molecules of the neurotransmitters usually diffuse across the synaptic cleft and they bind to the receptors of the postsynaptic cells.

Answer:

Neurotransmitters

Explanation:

Signaling molecules released at a synapse are called neurotransmitters.

Cells can be divided into 2 main categories. Eukaryotes(right side) and prokaryotes.

The facts about cells.

Cells are too small to see without a microscope.

There are two main types of cells.

1 Prokaryote were the earliest and most basic forms of life on Earth.

2 There are more bacteria in the body than in human cells.

3 Cells contain DNA.

4 Cells contain structures called organelles which have specific roles.

The four type of cells are :

1 Nerve cell.

2 Muscle cells.

3 Epithelial cells.

4 Blood cells.

5 Stem cells.

6 Fat cells.

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The papillary response of the right eye is the constriction of the pupil when a light is shone into it.

The papillary response of the right eye when a light is shone into the pupil is the constriction of the pupil. This is called the pupillary light reflex. When light enters the eye, it stimulates the photoreceptor cells in the retina. The information is then sent to the brain through the optic nerve, which triggers a response in the muscles of the iris to constrict the pupil. This helps regulate the amount of light entering the eye and protects the retina from excessive light exposure.

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Answer:

The limbic system

Explanation:

Limbic system is also named as paleomammalian cortex. Limbic system is located on both sides of thalamus beneath the cerebrum temporal lobe.

The limbic system controls the different functions like behavior, long term memory and emotion. This system is also referred as emotional brain as it controls the emotional state of an organism.

Thus, the correct answer is option (a)

Answer:

The limbic system

Explanation:

The limbic system of the brain is considered the emotional brain.

Answer:

Involuntary/glandular tissue.

Explanation:

Autonomic nervous system is a part of peripheral nervous system that control the important functions of our body.

Autonomic nervous system control the involuntary actions of the body. This nervous system control the heart beat regulation ( cardiac muscle), contraction of smooth muscle and secretion of the glands of an organism's body.

Thus, the correct answer is option (C).

Answer:

b. Voluntary/somatic tissue

e. Voluntary/skeletal muscle

Explanation:

b and e