For the average human, blood lactate:

a. begins to accumulate significantly at a point that is about 55-65% of Vo2 max

b. begins to accumulate significantly only when the Vo2 max is reached

c.can be used as an energy fuel by the heart and skeletal muscles

d. a and c

A controlled experiment in biology includes at least two groups, one of which does not receive the experimental treatment. It is repeated many times to ensure accurate results.

In biology, a controlled experiment includes at least two groups, one of which does not receive the experimental treatment. This helps to determine the effects of the treatment compared to a control group. It is important to repeat the experiment many times to ensure accurate results and account for any variability.

https://brainly.com/question/35799870

#SPJ6

A controlled experiment in biology uses at least two groups; an experimental group and a controlled group. The only variable that differs between these groups is the one being tested. Examining the results across these groups allows researchers to assess the impact of this variable.

A controlled experiment is a vital concept in scientific research. It involves at least two groups: the experimental group and the control group. The experimental group receives the experimental manipulation, which is the treatment or variable being tested, while the control group does not. The purpose of these two groups is to isolate and examine the effects of one variable.

In a controlled experiment, the one and only variable that differs between these groups is the independent variable, i.e., the treatment being tested. Observing changes in the dependent variable across these groups then allows the researcher to draw conclusions about the influence of the independent variable. Thus, if the results of the experiment reveal significant differences between the two groups, this is attributed to the impact of the independent variable.

These experiments can be lab-based or field-based depending on the nature of the study. Careful design, including random selection and assignment, along with proper ethical considerations are crucial for such experiments to yield reliable and accurate data.

https://brainly.com/question/4444046

#SPJ6

Answer:

A. lack both antigens A and B on their erythrocytes.

Explanation:

A person with blood type O would lack both antigens A and B on their erythrocytes.

Answer:

I think its one generation

Answer:

One generation

Explanation:

If two populations are merged, each with different frequencies of one allele at one location, and random mating occurs immediately; after a generation this population will be in Hardy-Weinberg equilibrium, as there were no evolutionary processes within the population and mating occurred entirely at random.

The Hardy-Weinberg equilibrium states that in a population in which crossings occur at random and over which there are no evolutionary factors, gene and genotypic frequencies remain constant over the generations.

The importance of the Hardy-Weinberg Balance for natural populations lies in the fact that it establishes a model for gene behavior. Thus, it is possible to stimulate gene frequencies and genotypic frequencies over generations and compare them with those obtained in practice. If the observed values are significantly different from the expected values, it can be concluded that evolutionary factors are acting on this population and that it is evolving. If the values do not differ significantly, it can be concluded that the population is in equilibrium and therefore not evolving.

Answer:

C) acetylcholine

Explanation:

Acetylcholine is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle.

However, norepinephrine, gamma aminobutyric acid, and cholinesterase are not excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle.

The excitatory neurotransmitter secreted by motor neurons that innervates skeletal muscle is acetylcholine. It is crucial in the motor nervous system with its main function being to lead to muscle contraction.

The excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle is acetylcholine.

Acetylcholine plays a crucial role in the function of the motor nervous system, especially within the neuromuscular junction which is where the motor neuron and skeletal muscle connect.

Once an action potential reaches the end of a motor neuron, acetylcholine is released from the neuron and binds to receptors on the surface of the skeletal muscle. This causes the muscle to depolarize and eventually leads to muscle contraction.

https://brainly.com/question/28101943

#SPJ3

Answer:

The liver have a hepatic portal vein and a hepatic vein for blood flow and transport of nutrients.

Explanation:

Hepatic portal vein is also known as portal vein that carries blood from the organs (gastrointestinal tract, pancreas and gallbladder) to the liver. The nutrients are also transfer by the hepatic portal vein.

Hepatic vein: This vein carry deoxygenated blood into the inferior vena cava from the liver. Total three hepatic veins brings deoxygenated blood from right, left and middle part of liver.

Answer:

[tex]96[/tex]Pa

Explanation:

Let "n" represents the normal flow condition and "a" represents the abnormal flow condition.

As per continuity equation -

[tex]v_{n}*A_{n}= v_{a}*A_{a}[/tex]----------- Eq (1)

Where "v" represents the velocity and "a" represents the area of artery

Given-

[tex]A_a=\frac{A_n}{4}[/tex]

Substituting the above relation in equation (1), we get -

[tex]v_a = \frac{v_n*A_n}{A_a}\\ v_a= 4v_n\\[/tex]

As per Bernoulli's theorem, we know that -

[tex]P_a-P_n= \frac{1}{2}pv_a^2-\frac{1}{2}pv_n^2\\P_a-P_n=\frac{1}{2}p[\frac{v_a*A_a}{A_n} ]^2\\P_a-P_n=\frac{1}{2}pv_n^2[16-1]\\P_a-P_n=\frac{1}{2}*1060*(0.11)^2*15\\P_a-P_n=96[/tex]Pa

The blood pressure difference between the normal and constricted segments of the artery can be calculated using Bernoulli's equation. As the cross-sectional area is reduced in the constricted segment, the blood speed increases and the pressure decreases. The difference in blood pressures can be determined by comparing the pressure energy per unit volume in the two segments.

The blood pressure difference between the normal and constricted segments of the artery can be calculated using Bernoulli's equation, which states that the sum of pressure energy, kinetic energy, and potential energy per unit volume is constant along a streamline in an ideal fluid flow. In this case, as the cross-sectional area of the artery is reduced to one-fourth in the constricted segment, the blood speed increases. As a result, the pressure in the constricted segment decreases due to the conservation of energy. The difference in blood pressures between the normal and constricted segments can be determined by comparing the pressure energy per unit volume in the two segments.

https://brainly.com/question/28203642

#SPJ3

Answer:

a. RER, microtubules, cytoplasm

Explanation:

The axoplasmic transport or axonal transport that moves the material at the rate of 1-5 mm/day is called slow axoplasmic transport. This system serves to deliver the materials required for regeneration of axons and axoplasm. It includes the movement of proteins from cytoplasm along the axon.

On the other hand, the fast axoplasmic transport moves the material at the rate of 200-400 mm/day. It serves to transport integral membrane proteins and secretory proteins formed on RER. The fast movement occurs with the help of motor proteins that move the material along the surface of microtubules present in the cytoskeleton of neurons.  

Answer:The populations are isolated and thus do not interbreed.

Explanation:

I just took the test.

The populations are isolated and thus do not interbreed in this stage of speciation.

Speciation, the formation of new and distinct species in the course of evolution. Speciation involves the splitting of a single evolutionary lineage into two or more genetically independent lineages.

The formation of the canyon acted as a barrier that prevented any mating between the separated populations due to this population get isolated and thus dont interbreed.

Learn more about speciation here:

https://brainly.com/question/13194077

#SPJ2

Answer:

Active transport

Explanation:

The process of transport of substances that uses energy and carrier proteins of the membrane is called active transport. Amino acids can not cross the hydrophobic core of the membrane and therefore, are transported through carrier proteins. The carrier proteins transport the amino acids using energy and the process is called active transport.

Answer:

Isometric contraction

Explanation:

The length of the muscle is changed during contraction only when the muscle tension during contraction can outstand the resistance exerted by the object to be lifted.  

During isometric contractions, the muscle tension is not sufficient to exceed the resistance of the object. Hence, there is no change in the length of the muscle. The isometric contraction does not bring about any body movements.  

Isometric contractions are the type of muscle contractions where the muscle fibers do not shorten. Despite the muscle producing tension, there is no movement because the force produced can't overcome the resistance of the load. Unlike isotonic contractions where muscle length changes to move a load, in isometric contractions the goal is often to remain stationary.

The type of contraction in which the muscle fibers do not shorten is called an isometric contraction. This type of contraction involves the muscle producing tension without changing the angle of a skeletal joint. Despite the muscle tension, there is no movement of the load, as the force produced cannot overcome the resistance provided by the load. This is because sarcomere shortening and increasing muscle tension are involved, but the goal is to remain stationary and not produce movement. Isometric contractions are crucial in daily activities such as maintaining posture and providing bone and joint stability.

In contrast, there are also isotonic contractions, in which muscle length changes to move a load. This includes both concentric and eccentric contractions, where the muscle either shortens or lengthens respectively.

https://brainly.com/question/13034164

#SPJ3

Answer:

Mutations and Genetic Drift

Explanation:

A mutation refers to the random changes in the genome of the organisms. Being a random event, it is not possible to calculate the effect of mutations on the allele frequency of a population.  

Genetic drift refers to changes in the allele frequency by chance event alone. Since the occurrence of chance events can not be predicted, the resultant changes in the allele frequency of the population can not be calculated.  

Answer:

11 year in girls and 12 years in boys

Explanation:

The volume of grey matter peaks at the adolescent age of child, however it starts growing since the childhood. It is considered that a girl’s adolescent age starts from 11 years while a boy’s adolescent age starts from 12 years. Thus, grey matter reaches at its peak when  girls reaches the age of 11 years and boy reaches the age of 12 years.

Grey matter starts declining as adulthood is reached in both male and female.

Answer:

The CRA-cAMP complex increases the rate of expression of lac operon when glucose is absent and lactose is present as nutrient.

Explanation:

CRP is the catabolite gene activator protein that forms a complex with cAMP. The CRP-cAMP complex facilitates the binding of RNA polymerase to the promoter region of the lac operon. This robust binding as stimulated by CRP-cAMP complex is followed by the formation of open complex and initiation of gene expression.  

Hence, the CRP-cAMP complex positively regulates the lac operon and increases its expression when glucose is not present.

Answer:

The correct option is a. refers to differences between the sexes with regard to features such as body size

Explanation:

Sexual dimorphism refers to a specific condition in animals and plants, which includes difference in the secondary characteristics of the male and female sexes of the same species. Sexual dimorphism is seen in many animals and some plant species. The difference in the secondary characteristics includes size, color, behavior, etc.

Sexual dimorphism, a term in biology, refers to the differences in physical characteristics between males and females of the same species beyond reproductive organs. These differences may be manifested in body size, coloration, or other physical attributes. Such differences vary widely among species, and while some correlation between dimorphism and social behaviors is observed, it is not a universal rule.

Sexual dimorphism refers to differences in physical characteristics between males and females of the same species, beyond differences in reproductive organs. These differences can relate to body size, coloration, or other physical attributes. It is a product of variance in reproductive success, often driving the evolution towards larger, more decorated, or stronger males as these traits can provide them advantages in obtaining mates.

Sexual dimorphism varies widely among species. Some species display quite pronounced sexual dimorphism, such as gorillas, where the males are significantly larger than the females. Other species, such as gibbons, display a low level of sexual dimorphism, correlating with long-term monogamy. Additionally, there are some species where the usual roles are reversed, with females being larger or more elaborate than males due to variances in reproductive success. It's crucial to note that there's no universal rule linking physical traits with behavioral traits, and each species presents a unique mix of these differences.

Conventionally, in many primate societies, a higher level of sexual dimorphism is linked with stronger male dominance, rigid hierarchy, and male competition for mating. However, the correlation between size and behavioral features shouldn't be perceived as a rule, as this varies greatly depending on the species and the environmental factors at hand.

https://brainly.com/question/33447031

#SPJ11

Answer:

the activity of my protein will be highest in the presence of other protein,and not higher than my protein activity alone

Answer: a.The individual always has the biometric in their possession.

Explanation:

Biometrics is a term that is used for the technology that is used to measure the bodily features and making a calculation on that basis. It is a method that can be used for the purpose of identification and authentication for the purpose of access control.

Among the given options, a.The individual always has the biometric in their possession. is the correct option. This is because of the fact that biometric measurements can be based upon physical characteristics such as fingerprints, retinal scans, and facial recognition. These features are common and unique to every human being. Hence, biometric system can be advantageous for physical access control.

Answer:

BLOOD PATHWAY:

Body > superior and inferior vena cava > right atrium > tricuspid valve > right ventricle > pulmonary semilunar valve > pulmonary artery > lungs > pulmonary vien > left ventricle > bicuspid/mitral valve> left ventricle > Aortic semilunar valve > Aorta > Body

The pathway goes like this:

From the body (we don't say first because this is a cycle), unoxygenated blood collected goes to the heart via the INFERIOR and SUPERIOR VENA CAVA then it empties into the RIGHT ATRIUM from there it passess through a valve called TRICUSPID valve, which prevents backflow of blood to the right atrium. The blood goes to our first pumping chamber, RIGHT VENTRICLE. The right ventricle pumps the blood through the PULMONARY SEMILUNAR VALVE which leads to the PULMONARY ARTERIES, which happens to be the only arteries that carry unoxygenated blood. From there it goes to the lungs to pick up oxygen and rid itself of carbon dioxide. The blood then goes back into the heart via the PULMONARY VEINS and like the latter, they are the only veins that carry oxygenated blood.

The blood then goes back into the heart, emptying into the LEFT ATRIUM. From there it goes through the BICUSPID VALVE or MITRAL VALVE and to the last and thickest pumping chamber, the LEFT VENTRICLE. The left ventricle pumps the blood through the AORTIC SEMILUNAR VALVE which opens out to the AORTA.

And at last, it goes back to your body.

Blood flows from the superior vena cava into the right atrium of the heart, from there it flows through the tricuspid valve to the right ventricle, and then to the lungs. After gas exchange in the lungs, blood returns to the heart's left atrium and then into the left ventricle through the mitral valve. Finally, the blood is pumped from the left ventricle through the aortic valve to the aorta and to the rest of the body.

The pathway of a red blood cell as it passes into and through the heart, to the lungs, back to the heart, and to the body starts in the superior vena cava. From the superior vena cava, blood enters the right atrium of the heart, passes through the tricuspid valve, and moves into the right ventricle. The blood is then pumped through the pulmonary valve into the pulmonary arteries, which lead to the lungs. Here, gas exchange occurs, oxygenating the blood. The oxygen-rich blood then returns to the heart through the pulmonary veins, entering the left atrium. It then goes through the mitral valve into the left ventricle. From the left ventricle, blood is pumped through the aortic valve into the aorta, the body's main artery. The blood is then transported to the rest of the body through a system of arteries, arterioles, and capillaries. Once the oxygen is delivered, the blood returns back to the heart via capillaries, venules, veins and finally the superior and inferior vena cava, ready to begin the journey again. Following this path, one can understand the flow of blood in the pulmonary and systemic circuits.

https://brainly.com/question/38392926

#SPJ3

Answer: Sulfonamides interfere with  folic acid synthesis in bacteria.

Explanation:

Sulfanilamide and other Sulfonamides are capable of inhibiting a variety of bacteria, interfering with a particular biochemical reaction (synthesis of the folic acid) which is essential for their survival. Sulfonamides are primarily used to treat urinary infections and for the treatment of otitis, bronchitis, sinusitis, and Pneumocystis pneumonia; It is used in combination with trimethoprim. Sulfonamides derivatives exert a wide range of antimicrobial activity against Gram-positive and Gram-negative bacteria.

Answer:

Skin

Explanation:

The tissues with high mitotic index have a number of cells undergoing mitosis. Among the given options, cells of skin exhibit the highest mitotic index. The skin forms the outer most covering of the body surface. Its cells are exposed to various agents of wear and tear.  

To replace the damaged cells, the cells of the skin undergo mitosis. So, skin exhibits the highest mitotic index.  

The skin tissue would have the highest mitotic index among the tissues listed. This is because skin is constantly exposed to environmental damage and needs frequent cell replacement, which requires a high rate of cell division. Muscle, kidney, and lung tissues generally have lower mitotic indices due to less frequent cell division.

The term mitotic index refers to the ratio of cells in a population undergoing mitosis. It is often used as an indication of the proliferative activity of the cell population. Mitosis is most frequently found in tissues that are dividing and growing or being replaced. Among the tissues listed, skin tissue would have the highest mitotic index.

This is because the skin is constantly being exposed to the external environment and is thus often damaged and needs to be replaced. The dead or damaged skin cells on the surface are frequently shed and need to be replaced by newer cells from the lower layers. This process requires a continuous cycle of cell division, hence a high mitotic index.

In contrast, the other tissues listed, such as muscle, kidney, and lung tissues, typically have lower mitotic indices. These tissues rarely undergo cell division, except for repairing damage or during growth. Thus, their mitotic indices are significantly lower than the skin's.

https://brainly.com/question/35868166

#SPJ3

Answer:

(D) H Vacuole

Explanation:

The vacuole is the organelle of the plant which contains water reserves of the plant and essential minerals required by the plant to grow. It also helps the plant to maintain its structure and provides rigidity

HOPE IT HELPS....

Answer:

The correct answer will be option D-H.

Explanation:

The eukaryotic cells contain organelles which help in the survival of the organisms.

The plant cell contains one of the largest organelle called vacuole which helps the plant cell to store the harmful as well as useful material inside the cell. The primary molecule it stores in the water which helps in maintaining the turgidity of the cell. It is due to this turgidity that vacuole determines the shape of the cell.

Thus, option D-H is the correct answer.

Answer:

Decimal reduction time [tex]= 990[/tex] cells per minute

Explanation:

Given -

Initial population of cells [tex]=10000[/tex]

Final population of cells  [tex]=100[/tex]

Total change in population of cells is equal to final population of cells minus the initial population of cells.

Total change in population of cells [tex]= 10000-100\\= 9900\\[/tex]

Total time taken by cell to reduce [tex]= 10[/tex] minutes

Decimal reduction  time

[tex]= \frac{9900}{10} \\= 990[/tex] cells per minute

Answer: False

Explanation: The COMPLEMENT SYSTEM consists of proteins synthesized in the liver. They are activated by inespecific harmful substance (antigen) and begins a cascade of proteins that finally forms an attack complex against bacteria.

The COMPLEMENT is part of the INNATE IMMUNITY, because it is an inherent response, something all humans born with, and it is part of the first defense barrier against any antigen. Part of the innate immunity are too: natural killer cells, neutrophils, monocytes, dendritic cells and macrophages.

On the other hand, the ADAPTATIVE IMMUNITY, is the response that the body develops after being exposed to an antigen before. It is like something that the body recognizes, and then "learns" how to act against it. Part of the adaptative immunity are: lymphocyte T and B, and the antibodies (substances called Immunoglobulins). The immunoglobulins (Ig) are glycoproteins present in the blood.

Answer:

cytoplasmic, transmembrane

Explanation:

Pulse chase experiment is an important technique used to analyze the cellular process by labeling the cells with radioactive compound.

The radioactive amino acids is injected into the rabbit's retina. Two different moving peaks are observed during the experiment.  The first peak moved at 0.5-2 mm/day and second peak at 200-400 mm/day. These peaks are observed due to difference in the synthesis and transport rate of the protein. Cytoplasmic protein has slow transport and sorting rate, indicates the first peak. The second peak corresponds to transmembrane protein.

Thus, the correct answer is option (a).

Answer:

Cancerous tissue has high mitotic index.

Explanation:

Mitotic index may be defined as the number of dividing cells divided by the total number of cells. Cell proliferation can be measured by mitotic index.

Cancerous cells are highly dividing cells and are less differentiated than normal cells. Cancer cells have higher mitotic index because the number of dividing cell is more in cancerous cell than the normal cells.

Answer:

Cancerous tissue has high mitotic index.

Explanation:

Answer:

Proteins are broken down into amino acids, carbohydrates into simple sugars and fats into simple fatty acids.

Explanation:

Digestion may be defined as the process of breakdown of biomolecules into simpler substances with the help of enzymes and digestive juices.

The process of breakdown of carbohydrates starts in the mouth with the help of enzyme salivary amylase. Carbohydrates are broken into simple sugars and later absorbed by the body. The absorption and digestion of proteins is completed into the small intestine.  Proteins are broken converted into amino acids after complete digestion. Lipase enzyme breaks down the fat into simple fatty acids and glycerol.

In digestion, proteins, carbohydrates, and fats are broken down into amino acids, monosaccharides, and glycerol and fatty acids respectively, which are then absorbed by the body.

During the process of digestion, different types of macromolecules are broken down into their smaller components for absorption. Proteins are broken down into amino acids, carbohydrates into monosaccharides, such as glucose, and fats, or triglycerides, are broken down into glycerol and fatty acids. This breakdown is crucial for the molecules to be small enough to be transported across the mucosal membrane and be utilized by the body.

The complex carbohydrates are first acted upon by enzymes like amylase, which break them down into simpler sugars, or monosaccharides. Proteins are degraded into amino acids by enzymes such as trypsin, pepsin, and peptidase. Lipids are broken down by lipase into glycerol and fatty acids. The smaller molecules resulting from the actions of these enzymes can then be absorbed by the cells lining the small intestine and used for various bodily functions including energy production, cellular repair, and growth.

Answer: All collagen family members consist of peptide chains arranged in a parallel chain to an axis, forming the collagen fibers.

Explanation:

The term “collagen” is used to denote a family of 27 isoforms proteins found in the connective tissues of the body. It is the most important compound in the connective tissue and is an important structural element in multicellular organisms. It contains peptide chains amino acids glycine, proline, lysine, hydroxylysine, hydroxyproline, and alanine. These chains are organized in parallel to an axis, forming the collagen fibers, that provides strength and elasticity to the structure. The collagen molecule has 280 nm of length, with molecular weight 300,000 Da, stabilized by hydrogen bridges and intermolecular bonds.

Answer:

Option (D).

Explanation:

Pesticide are the chemicals used to kill pests or other harmful organisms. They are mainly used for the safety of agriculture crops.

Pesticides are quiet useful in the agriculture fields but some organisms has shown an inherent degree of pesticide. Pesticide doesnot degrade easily and accumulate in further trophic levels in the environment. Pesticide accumulation leads to the phenomena of biological magnification.

Thus, the correct answer is option (d).

Answer:

The glomerulus is a tiny structure which is made up of capillary blood vessels which filters the waste product from the blood to form urine.

The glomerulus makes the functional unit called the nephron. Each nephron is made up of structures through which urine passes in the following way :

1. Glomerular capsule (Bowman's capsule)- capsule surrounding the glomerulus where fluid and solutes are filtered out of the blood.

2. Proximal Convoluted Tubule (PCT) -  tube where water and salt reabsorption takes place.

3. The Loop of Henle- U-shaped tube which transfers the fluid from the proximal tubule to the distal tubule.

4. Distal Convoluted Tubule (DCT)- tubule which is the final site of reabsorption in the nephron.

5. Collecting duct - duct which transfers the urine to the ureter.

6. Ureter- thin tube-like structures of 8 to 10 inches long which force urine to away from the kidney.

7. Urinary bladder- hollow, balloon-shaped organ stores urine for 3-5 hours.

Answer:

correct option a

Explanation:

movement of water molecule from an area of higher concentration to an area of lower concentration

Answer: C. Involves the replication of environmental conditions and human responces to those conditions

Explanation:

The maintenance of homeostasis is a key feature of most levels of any organism’s biology.

In biology, homeostasis  is the state of steady internal, physical, chemical, and social conditions maintained by living systems.This is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits .

Other variables include the pH of extracellular fluid, the concentrations of sodium, potassium, and calcium ions, as well as the blood sugar level, and these need to be regulated despite changes in the environment, diet, or level of activity. Each of these variables is controlled by one or more regulators or homeostatic mechanisms, which together maintain life.It is a key feature of most levels of any organism’s biology.

Thus, option D is correct.

Learn more about homeostasis,here:

https://brainly.com/question/31789146

#SPJ4