40) When blood pressure is normal, the receptors in arterial walls fire action potentialsA) continuously.B) very seldom

Answer:

c. Filiform

Explanation:

The filiform papillae are pointed and threadlike in appearance. They are present on the surface of the tongue. The filiform papillae have tactile receptors and lack the taste buds. Since the filiform papillae lack taste buds, they do not serve in the reception of any taste. Rather, the function of filiform papillae is to help the tongue to move food in the mouth.

Soft-shell crabs have soft shells because they have recently molted and their new exoskeleton has not had time to harden. The exoskeleton is made of chitin and is crucial for protection and movement but must be shed periodically as the crab grows.

The soft shells of soft-shell crabs are due to the fact that they have recently molted. Crabs, including soft-shell crabs, have an exoskeleton which is an external, hard shell that provides defense against predators, supports the body, and facilitates movement. The exoskeleton, made primarily of a substance called chitin, does not grow as the crab grows.

Therefore, crabs must periodically shed their old shell in a process known as molting, during which the new exoskeleton underneath is initially soft until it hardens. This molting process is necessary because the exoskeleton is acellular and cannot expand. Soft-shell crabs are caught for consumption shortly after they molt, before their new exoskeleton has had time to harden.

Answer:

Option). NK cells.

Explanation:

Cluster of differentiation 8 (CD8) can bed defined as a transmembrane glycoprotein that acts a co-receptor for the receptor present on T cells (TCR). The CD8 is marker for [tex]T_c[/tex] cells (cytotoxic T cells) as it is predominantly present on cell surface of these cells.

Along with cytotoxic cells, CD8 molecule is also expressed in surface of natural killer cells (NK cells), thymocytes, and myeloid dendritic cells.

Hence, a cell having CD8 on its surface (cytotoxic T cell) would be most similar to NK cells.

The correct answer is c. monocytes.

CD8, also known as cluster of differentiation 8, is a protein found on the surface of certain cells of the immune system. Specifically, CD8 is expressed on the surface of cytotoxic T cells, which are a type of lymphocyte that plays a crucial role in the immune response. These cells are capable of directly killing infected cells, particularly those infected with viruses or transformed by cancer.

Monocytes are a type of white blood cell that circulate in the blood and can differentiate into macrophages and dendritic cells once they migrate into tissues. Monocytes express CD8 at a lower level compared to the high levels found on cytotoxic T cells, but they are still part of the immune system's response to infection and are involved in phagocytosis and antigen presentation.

Let's consider the other options:

a. Follicular dendritic cells: These cells are found in lymphoid follicles and are involved in the humoral immune response by presenting antigens to B cells. They do not express CD8.

b. NK cells (Natural Killer cells): These cells are part of the innate immune system and can kill infected or cancerous cells without prior sensitization. While they share some functions with CD8+ T cells, they do not express CD8.

d. Dendritic cells: These are antigen-presenting cells that process antigen material and present it on the surface to other cells of the immune system. They can express CD8, but not typically at the levels seen on cytotoxic T cells.

e. Macrophages: These are specialized cells involved in the detection, phagocytosis, and destruction of bacteria and other harmful organisms. While they can be derived from monocytes, they do not typically express CD8.

Therefore, monocytes are the cells that would be most similar to or have the most in common with a cell bearing CD8 on its surface, as they can express CD8 and are part of the immune system's response.

Answer:

The influx of sodium ions causes the depolarization in the resting cells.

Explanation:

Resting cells has the membrane potential of -70 mV. Potassium ions are abundant in the resting cell.

The influx of sodium ions in the resting cells will increase the membrane potential from -70mV to 30mV. The cells will depolarize die to the influx of sodium ions and the cell inside environment will become more positive than outside environment of the cell.

Thus, the cells will depolarize by the influx of sodium ions.

Answer:

20 million years

Explanation:

If we have a neutral mutation rate of one mutation per 5 million years, then the total of eight mutation between the two different species would be 20 million years. This is because both species will have 4 mutations in those 20 million years, so combined, both by 4, will have 8 mutations between them. So few mutations on so much time will result in two species that are very similar to each other even after 20 million years of evolution, even making them hardly distinguishable, especially if it comes to defining fossil records from them both. A nice example of this are the members of the felidae (cat) family, which are all very closely related, and are almost identical, thus making it extremely hard to distinguish two species of the same or similar size by their fossils.

Answer:

The region where the embryoblast contacts the trophoblast is called the embryonic pole. ... Just before implantation, the cells in the embryoblast start to differentiate into two layers - the epiblast (primary ectoderm), and an internal layer of cuboidal cells called the hypoblast (or primary endoderm).

Answer:

Sheep Brain:

Sheep brain is smaller in size the human brain. The convolutions or folds are absent in sheep brain. Olfacory bulb is more developed in shhep's brain as compared to human brain. Sheep brain is more elongated in shape.

Human brain:

Human brain is large in size. The convolutions are more numerous in human brain. Human's brain olfactory bulb is less developed as compared with sheep's brain. Human brain is round in shape.

Hello There!

The "TUNDRA" biome is the least productive biome there is.

The tundra biome is known for its frost-molded landscapes, very low temperatures and little precipitation.

There are two types of the tundra biome.  These are called the alpine tundra and the polar/arctic tundra.

Answer:

tundra

Explanation:

apex

Answer:

Cardiac muscle.

Explanation:

Cardiac muscle is also known as heart muscle. These muscles regulate the proper working and functioning of the heart.

Cardiac muscles are involuntary muscles and show striations under the microscope. These muscles are uninucleate and connected by the intercalated disc. Cardiac muscles are branched so that each cardiac cells may attach with atleast with or four other cardiac cells.

Thus, the correct answer is option (A).

Answer: Option B

Explanation: The first line of defense acts a barrier and does not allows the foreign materials to enter inside the body. It includes chemical and physical  barriers that are always ready to protect the body from infection.

Example: Skin and mucous membrane.

Skin is largest organ and it acts as a barrier between pathogens and human body. It acts a waterproof material and the pathogens cannot get inside through skin unless the skin is broken.

Mucous membranes also acts as first line of defense and breaks the cell wall of many bacteria entering through the openings of the body.

So, skin and mucous membrane are the first line of defense.

Answer:

Thyroid Stimulating Hormone (TSH)

Explanation:

TSH also called thyrotropin is released by the anterior pituitary gland and stimulates the thyroid glands to secrete the thyroid hormones throxine, triiodothyronine and tetraiodothyronine. Release of TSH is due to the stimulation of the anterior pituitary gland by the hypothalamus through the hormone Thyroid Releasing Hormone (TSH). Adrenocorticotropin hormone (ACTH) is released by the anterior pituitary gland due to hypothalamic stimulation through the hormone Corticotropin Hormone (CRH) that helps in synthesis and release of ACTH.

Answer:

C. Monocytes

Explanation:

Monocytes are 10-24 micrometer in diameter as compared to red blood cells which are only 7-8 micrometer in diameter. Monocytes are one of the agranular leukocytes and transform into macrophages when they migrate from blood to tissues. Their function is to kill the pathogens and cellular debris by the process of phagocytosis.

Answer:

Frequencies of allele [tex]A_{1}[/tex] and [tex]A_{2}\\[/tex] are [tex]0.74[/tex] and [tex]0.26[/tex] respectively.

Frequencies of Individuals with genotype [tex]A_{1}A_{1}, [tex]A_{2}A_{2} and [tex]A_{1}A_{2} are [tex]0.55, 0.128, 0.32[/tex] respectively.

Explanation:

As per Hardy Weinberg's equation -

[tex]p^{2} +q^{2} +2pq= 1[/tex] ----------Equation (A)

[tex]p+q= 1[/tex]-----------Equation (B)

Where "p" represents the frequency of "[tex]A_{1}[/tex]

"q" represents the frequency of "[tex]A_{2}[/tex]

[tex]p^{2}[/tex] represents frequency of individual  [tex]A_{1}A_{1}[/tex]

[tex]q^{2}[/tex] represents frequency of individual [tex]A_{2}A_{2}[/tex]

[tex]pq[/tex] represents frequency of  individual [tex]A_{1}A_{2}[/tex]

Here genotype frequencies are  -

[tex]A_{1}A_{1} = 77\\p^{2} = \frac{77}{140} \\= 0.55\\[/tex]

[tex]A_{2}A_{2} = 18\\q^{2} = \frac{18}{140} \\= 0.128\\[/tex]

Substituting this values in equation A, we get

[tex]0.55 + 0.128 + 2pq = 1\\2pq = 1-(0.128+ 0.55)pq = 0.321[/tex]

Frequencies of allele [tex]A_{1}[/tex] and [tex]A_{2}\\[/tex] are -

For [tex]A_{1}[/tex][tex]= \sqrt{p^{2} } \\= \sqrt{0.55} \\= 0.74[/tex]

Substituting this value in equation B, we get

[tex]p+q=1\\0.74 + q = 1\\q = 1-0.74\\q = 0.26[/tex]

Frequencies of allele [tex]A_{1}[/tex] and [tex]A_{2}\\[/tex] are [tex]0.74[/tex] and [tex]0.26[/tex] respectively.

Frequencies of Individuals with genotype  [tex]A_{1}A_{1}, A_{2}A_{2}, A_{1}A_{2}[/tex]are [tex]0.55, 0.128, 0.32[/tex] respectively.

Answer:

A) B cells produce plasma cells, which secrete antibodies into the blood

Explanation:

There are two types of lymphocytes present in blood. These are namely, B lymphocytes and T lymphocytes. The B lymphocytes are activated with help of T lymphocytes. The activated B cells divide and produce a large number of cells that differentiate into the plasma cells. These plasma cells finally produce antibodies against specific antigens.

The correct statement about lymphocytes is that B cells produce plasma cells, which in turn secrete antibodies into the blood. This is a vital part of the immune system's response to pathogens and infections.

In the context of the human immune system and lymphocytes, the correct statement is 'B cells produce plasma cells, which secrete antibodies into the blood.' This statement accurately describes an important function of B cells as a type of lymphocyte. B cells, upon activation, differentiate into plasma cells that produce and secrete antibodies, which help in fighting off pathogens and infections in the body. This process is a vital part of the immune system's response to foreign substances.

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Final answer:

Hydrochloric acid in the stomach functions to create an acidic environment necessary for killing bacteria and enabling the digestion of proteins by activating the enzyme pepsin and denaturing proteins for efficient breakdown.

Explanation:

Hydrochloric acid (HCl) in the stomach serves several important functions in the digestive process. The stomach produces HCl as part of the gastric juice, and its functions include:

The acidic environment created by hydrochloric acid is critical for the overall efficiency of the digestive process. It prepares ingested food for further digestion and absorption in the small intestine, ensuring that nutrients are properly broken down and made available for absorption into the bloodstream.

Answer:

Medulla oblongata

Explanation:

Medulla oblongata is the part of hindbrain and have three vital centers located in it. The vital centers present in medulla are:

1.  Cardiac center

2. respiratory center

3. and vasomotor center.  

The cardiac center is also known as cardio inhibitory center and is involved in regulation of heart beat. The basic rhythm of breathing is under regulation of respiratory center while diameter of blood vessels is regulated by vasomotor center.

Answer:

Hemopoiesis

Explanation:

Blood is the main connective tissue and consists of plasma and formed elements. The formed elements of blood are erythrocytes, leukocytes and thrombocytes.

Hemopoiesis is the process of formation of red blood cells, white blood cells and platelets. The process of hemopoiesis in adults occur in the bone marrow. Hemocytoblast leads to the formation of all formed elements of the blood.

Thus, the correct answer is option (B).

Answer:

B. hemopoiesis

Explanation:

The process by which formed elements are produced is called hemopoiesis.

Answer:

B

Explanation:

The child may go through growth spurts at 7-14 days old, between 3-6 weeks old, around 4 months old, and around 6 months old. So feeding them at that consistency will help in their development.

Answer:

Explanation:

a damming a river                increases the supply. Supply side solution. There's more water there.

b desalinating seawater      definitely increasing the supply. You create drinking water from what was not there before.

c invading nation for rivers  increasing the supply (not by much. The people who are there still need their water).

d Raising water prices          reducing the demand

e Tax breaks                          reducing (and maintaining) the demand

f  drip irrigation                      reducing the demand.  

Answer:

Explanation:

As stated in the above question, supply side solutions increase the supply of fresh water. This means that the options that will increase the level of fresh water that will be offered to the consumer will be on the supply side, that is, those options that will provide plenty of choice for the consumer should be on the supply side, so we can say that the solutions are: desalinating seawater, damming a river to create a reservoir, a nation invading a neighboring country to access their rivers

The above question also states that demand-side solutions will reduce demand for fresh water. This means that these solutions should discourage consumers from paying for or limiting their use of fresh water. These solutions are: raising water prices for consumers and businesses, providing tax breaks for companies that use less water, requiring low-flow shower heads in new homes, replacing inefficient irrigation with more-efficient drip irrigation to grow crops

Answer:

Let:

Y = Yellow           R = Round

y = green             r = Wrinkled

If you look at the F1 generation, all the plants are round and yellow, so these are the dominant traits and each offspring is heterozygous for both traits. The cross for the F2 generation would then be:

YyRr x YyRr

In a Punnett it would look like the attached picture.

For the forked-line diagram, first you will need to know the gentypes and ratio of each trait in a monohybrid cross. Select one trait, and then branch each gentype to the next trait, linking it with each possible genotype combination of the monohybrid cross.

Attached is a picture of the Forked Branch diagram for this cross.

Mendel crossed pea plants with different traits and observed the inheritance patterns in the F2 generation. The Punnett square and forked-line methods can be used to diagram this cross. The F2 generation showed a ratio of 9/16 round yellow seeds, 3/16 wrinkled yellow seeds, 3/16 round green seeds, and 1/16 wrinkled green seeds.

Mendel crossed peas with round seeds and yellow cotyledons (seed leaves) with peas having wrinkled seeds and green cotyledons. In the F1 generation, all the plants had round seeds with yellow cotyledons. To diagram this cross through the F2 generation, we can use both the Punnett square and forked-line methods. Using the Punnett square, we can see that in the F2 generation, there is a 9/16 probability of getting round yellow seeds, 3/16 probability of wrinkled yellow seeds, 3/16 probability of round green seeds, and 1/16 probability of wrinkled green seeds. This demonstrates independent assortment of the two traits.

Answer:

A. The ash would increase the albedo and decrease the global temperature

Explanation:

The volcanoes can have a big impact on the global temperature. If the volcanic eruption is big enough, and the volcanoes manages to propel very large amount of ash in the atmosphere, the whole planet will feel the effect. The ash will make a layer in the atmosphere around the planet. This layer will increase the albedo of the atmosphere, as the ash will block big portion of the sunlight. That will result in much less sunlight reaching the surface of the Earth, thus in sharp decrease in the global temperatures.

The mouse in the scenario would survive. This result comes from Griffith's experiments showing that transformation, where a strain of bacteria changes by contact with another strain's DNA, requires living bacteria. Since both types of bacteria are heat-killed, they can't cause pneumonia or become transformed.

In the scenario proposed, where Griffith mixed some heat-killed type IIIS (virulent) bacteria and some heat-killed type IIR (non-virulent) bacteria and injected these into a mouse, the mouse would have survived. This conclusion comes from Griffith's transformation principle experiments.

This effect occurs because transformation, or the process of one strain of bacteria changing due to being in contact with another strain's DNA, requires living bacteria. Since both types of bacteria, IIIS and IIR, are heat-killed, they are not alive and thus not capable of being transformed or causing pneumonia.

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Answer:

Mutations in introns create alternative splicing site which in turn make mRNA with reduced or no translation.

Explanation:

Introns regulate the splicing of heterogenous RNA during post transcriptional modifications as well as affect the stability of mature mRNA. The stable mRNA is more likely to be translated into proteins. So, introns also regulate the translation of mRNA.  

In human beta thalassemia, mutations in intron create alternative splicing sites which in turn affect the formation of beta globin chain of hemoglobin. Lack of beta globin chain reduces the amount of functional hemoglobin and causes anemia.

Answer:

Mandibular Fossa occurs on temporal bone.

Explanation:

Mandibular fossa also known as glenoid fossa, the depression of temporal bones. Mandibular fossa articulates with the mandible and interacts with mandibular condyle. Glaserian fissure divides the mandibular fossa into two parts.

Articular tubercle bounds the mandibular fossa anteriorly. The mandibular fossa is bounded posteriorly by the temporal bone.  Mandibular fossa development may get arrested due to the separation of mandibular condyle.

Answer:

Nerve impulse provide signal to brain that controls the body position and position of muscles for movement in case of musculoskeletal system, and in special senses too information is gathered via senses and transmitted in the form of impulse to the brain.

Explanation:

Special senses include: vision, hearing, balance, taste and smell. Sensory receptors are present on these special senses which generates nerve impulse upon external or internal stimulus and this impulse travels to the central nervous system  via sensory nerve and is processed to produce further response.

Musculoskeletal system also have sensory receptors in joints and in muscles that produce nerve impulse, which travel to the brain and provide information about body positions and movements.

Answer:

the styloid process is located rt.above or superior to the sternum.

of the chest, between the rib cage.

Explanation:

it is actually located rt. above the sternum.

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"Natural" patterns occur all around us in nature.

Answer:

Bio molecules can be defined as the molecules that is synthesized or produced by the cells inside living organism.

Explanation:

Biomolecules have a huge range of size and structure. They perform a variety of function depending on their structure and size.

There are mainly 4 major types of biomolecules: Carbohydrates, nucleic acids, lipids and proteins.

"Bio-molecules are substances that are produced by living organisms. These molecules are essential for life and play a wide variety of roles in cellular processes and functions.

The major types or groups of bio-molecules include:

1. Carbohydrates: These are composed of carbon, hydrogen, and oxygen, with a general formula of [tex]\( C_x(H_2O)_y \)[/tex]. They serve as energy sources, structural components, and are involved in cellular communication. Examples include glucose, starch, and cellulose.

2. Lipids: These are a diverse group of molecules that are mainly composed of carbon and hydrogen, and are hydrophobic. They include fats, oils, waxes, and steroids. Lipids are important for energy storage, as components of cell membranes, and as signaling molecules.

3. Proteins: These are complex molecules made up of amino acids linked by peptide bonds. Proteins perform a vast array of functions, including catalyzing metabolic reactions (enzymes), providing structural support, transporting molecules, and mediating cellular communication.

4. Nucleic Acids: These are polymers of nucleotides, which are composed of a sugar (ribose or deoxyribose), a phosphate group, and a nitrogenous base. Nucleic acids, such as DNA and RNA, carry genetic information and are involved in protein synthesis.

5. Vitamins: These are organic compounds that are required in small quantities for various metabolic processes. They are not synthesized by the body and must be obtained from the diet. Vitamins can act as coenzymes, antioxidants, and are involved in processes such as blood clotting and vision.

6. Minerals: Although not organic, minerals are inorganic elements that are crucial for life. They are involved in various physiological processes, including the formation of bones and teeth, maintaining fluid balance, and participating in enzymatic reactions.

These bio-molecules are the building blocks of life and their interactions and functions are the basis for all biological processes."

Answer:

hey...im not sure about the answer but i think it is the 2nd option which is: rocks buried deeply and melted by intrusion rock erodedaway and deposited in ocea n base

hope it helps

Metamorphic rocks are produced when rocks are affected to high pressures, high temperatures, hot mineral-rich fluids, or, more usually, any accumulation of these possessions. Thus, option B is correct.

If subjected to sufficient heat and pressure, sedimentary rocks like bituminous coal, limestone, and sandstone can undergo nonfoliated metamorphic rock formation, giving rise to anthracite coal, marble, and quartzite.

These kinds of conditions can be found deep inside the Earth or where tectonic plates collide.

Metamorphism, which occurs when magma interacts with the surrounding rock, is another process that can produce nonfoliated rocks.

Therefore, deep-buried rock that has been melted by incursion rock was lost to erosion and dumped in the ocean basin.

Learn more about metamorphic rock here:

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Answer:

yes

Explanation:

As they can be the family of the same father and mother