Peptidoglycan is present in the cell walls of which of the following groups of organisms? you can select more than one if more than one applies)
-plants -archaea
-protists
-eubacteria

Acquisition of new characteristics by the host cell is Transduction of specific genes and Immunity to reinfection by the same phage. Therefore the correct option is option B and C.

Lysogeny is a process in which a virus (bacteriophage) infects a bacterial cell and inserts its genetic material (DNA) into the bacterial chromosome without immediately destroying the host cell. The integrated viral DNA is known as a prophage, and the host cell is known as a lysogeny.

During this period, the bacterium divides, and the virus genetic material is transmitted to each of its daughter cells along with the bacterium genetic material. The lysogeny bacteria will continue to produce the viral DNA but not the virus's structural proteins.

This process results in immunity to reinfection by the same phage, but not by any other phage. Thus, lysogeny can result in transduction of specific genes and immunity to reinfection by the same phage. Therefore the correct option is option B and C.

For such more question on Transduction:

https://brainly.com/question/12836556

#SPJ11

The function of the basilar membrane, hair cells, and tectorial membrane are as follows: The sound waves cause the basilar membrane to vibrate first. The hearing receptors are embedded in the hair cells. The structure that bends the hearing receptors but does not vibrate itself is the tectorial membrane. The hearing receptors are connected to the basilar membrane by supporting cells. As a result of this vibration, hair cells are bent. Hearing receptors are called hair cells.

The cochlea is an organ of the inner ear that is shaped like a snail shell. It contains tiny hair cells that are responsible for picking up sound vibrations and transforming them into nerve signals that can be interpreted by the brain.

The cochlea contains a fluid-filled cavity that is set in motion by sound vibrations. The basilar membrane is a structure that runs along the length of the cochlea and separates the fluid-filled cavity into two chambers. When sound vibrations enter the cochlea, they cause the basilar membrane to vibrate.

This vibration causes the hair cells, which are embedded in the basilar membrane, to bend. The tectorial membrane, which is located above the hair cells, does not vibrate but is responsible for bending the hair cells when the basilar membrane vibrates. The bending of the hair cells causes electrical signals to be sent to the brain, which are then interpreted as sound.

Hence, the sound waves cause the basilar membrane to vibrate first. The hearing receptors are embedded in the hair cells. The structure that bends the hearing receptors but does not vibrate itself is the tectorial membrane. The hearing receptors are connected to the basilar membrane by supporting cells. As a result of this vibration, hair cells are bent. Hearing receptors are called hair cells.

To know more about cochlea, refer here:

https://brainly.com/question/29839700#

#SPJ11

Answer:

The low-density tissue at the end of bones is called the spongy bone or cancellous bone. Unlike the compact bone that makes up the outer layer of bones, spongy bone has a porous and honeycomb-like structure with many spaces filled with bone marrow.

Spongy bone is found at the ends of long bones, such as the femur and the humerus, as well as in other bones, including the vertebrae and the pelvis. It provides structural support to the bone while also allowing for flexibility and shock absorption.

Spongy bone also plays an important role in bone metabolism as it contains red bone marrow, which produces red blood cells, white blood cells, and platelets. It also contains stem cells that can differentiate into osteoblasts, the cells responsible for bone formation, helping to maintain bone health and repair damaged bone tissue.

In the respiratory system, the proper order starting as you inhale air through the nose down to the lungs is: Nasal cavity > Pharynx > Larynx > Trachea > Main bronchi > Segmental bronchi > Bronchiole > Terminal bronchiole > Respiratory bronchiole > Alveolus. Hence, option B is correct.

The respiratory system is the system responsible for breathing. It has various components and organs that work together to enable breathing. The respiratory system comprises the nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, respiratory bronchioles, and alveoli.

Nasal cavity: This is the first stage in the respiratory system where air enters. It is also known as the nose.

Pharynx: It is a muscular tube located between the mouth and the larynx. It helps in the passage of food and air.

Larynx: It is a part of the respiratory system that connects the pharynx to the trachea. It has vocal cords and is responsible for sound production.

Trachea: This is a tube that connects the larynx to the bronchi. It is also known as the windpipe.

Main bronchi: The trachea divides into two main bronchi. Each bronchus leads to one lung.

Segmental bronchi: Each main bronchus is further divided into smaller segments called segmental bronchi.

Bronchiole: The segmental bronchi are further divided into bronchioles.

Terminal bronchiole: The bronchioles further divide into terminal bronchioles.

Respiratory bronchiole: They are thin-walled tubes that are responsible for gas exchange.

Alveolus: The respiratory bronchiole leads to the alveoli, which are small air sacs that are responsible for gaseous exchange.

Therefore in the respiratory system, the proper order starting as you inhale air through the nose down to the lungs is: Nasal cavity > Pharynx > Larynx > Trachea > Main bronchi > Segmental bronchi > Bronchiole > Terminal bronchiole > Respiratory bronchiole > Alveolus.

Learn more about respiratory system here:

brainly.com/question/4190530

#SPJ11

The neural communication varies greatly from when we are tapped gently on the arm in comparison to when we are slapped across the face. When we slapped that strongly triggers and increases the number of times those neurons fire. But when we tap on the arm that triggers fewer neurons to be fired.

Communication between neurons occurs electrochemically. Neurotransmitter receptors can be found on the dendrites of neighboring neurons. If the impulses from neighboring neurons are strong enough, an action potential will travel the length of the axon to the terminal buttons, releasing neurotransmitters into the synapse in the process.

Many neurotransmitters serve a variety of purposes. Unbalances in a specific neurotransmitter system frequently play a role in psychiatric disorders. As a result, doctors often prescribe psychiatric medications to try to rebalance the neurotransmitters. For a certain neurotransmitter system, drugs can either behave as agonists or antagonists.

To know more about neural communication click here:

https://brainly.com/question/5532381

#SPJ4

The steps hypothesized in the derivation of the land plant life cycle (alternation of generations) from the charophycean green algae life cycle is starting from the emberyophyte which evolves and adapts by developing body parts for both eating and reproduction until the sporophyte produces spores

Embryophytes (land plants) evolved from the charophycean green algae. Changes in the water content of the environment forced the plants to adapt. During this period of adaptation, land plants developed a cuticle and stomata, which helped them retain moisture. Plants also evolved specialized tissues to conduct water and nutrients from one part of the plant to another. Asexual reproduction in charophycean algae became sexual reproduction in land plants.

During sexual reproduction, land plants alternate between two generations: the haploid gametophyte and the diploid sporophyte. The gametophyte produces gametes through mitosis.8. Two gametes unite to form a diploid zygote that grows into a sporophyte. The sporophyte produces haploid spores through meiosis. Spores grow into gametophytes and the cycle begins a new.

Learn more about green algae at:

https://brainly.com/question/29824313

#SPJ11

The statement "It favors extremes in traits" is true about disruptive natural selection.

Disruptive natural selection occurs when extreme traits are favored over intermediate traits, leading to a bimodal distribution of traits in a population. This means that individuals with extreme traits at both ends of the distribution have a higher fitness compared to individuals with intermediate traits. As a result, the population becomes less homogeneous and more specialized in the extreme traits that are favored by natural selection.

Oysters of different colors—dark and light—are one instance of disruptive selection. Oysters with dark or light colours can blend in more effectively. Dark oysters can hide behind the shadow of the rocks, whereas light oysters can blend in with the rocks.

To know more about disruptive natural selection visit:-

brainly.com/question/30479979

#SPJ1

A B cell is undergoing a test for reactivity to self-antigen. The two potential outcomes of this test are shown in the given diagram. The labels should be dragged to the panel where the listed event are A. Positive selection (Panel A), B. Negative selection (Panel B), C. Anergy (Panel C), D. Apoptosis (Panel D)

There are two potential outcomes to the test for reactivity to self-antigen, which are anergy or apoptosis. Reactivity of B-cells to self-antigens is the mechanism that governs self-tolerance. If B-cells with specificity for self-antigens avoid apoptosis or anergy, autoimmune responses may emerge.

The diagram shows the following four panels. Panel A: B cell without self-antigen reactivity is shown. Panel B: B cell with self-antigen reactivity is shown. Panel C: A B-cell undergoing anergy is shown. Panel D: A B-cell undergoing apoptosis is shown. The following labels should be dragged to the panels where the event is occurring, A. Positive selection (Panel A), B. Negative selection (Panel B), C. Anergy (Panel C), and D. Apoptosis (Panel D). Thus, the correct labels should be dragged to the correct panels.

Learn more about apoptosisat:

https://brainly.com/question/30746633

#SPJ11

Gene switch mutations could lead to evolution by natural selection as they affect the expression of a gene. This is based on the information you have gained from the video clips and animations.

If a gene switch is turned on in a cell that it was not turned on before, it leads to the production of a protein that is beneficial to the organism in that environment.This can give the organism an advantage in that particular environment, allowing it to reproduce more effectively, leading to the selection of the new beneficial trait. Gene switches can evolve by acquiring mutations, leading to changes in the sequence of the DNA that regulates gene expression.Based on the information, we have gained from the video clips and animations, gene duplication events are important ways that new genes evolve. One of the most common ways that new genes evolve is through gene duplication events.

A gene duplication event is when a gene is duplicated, leading to two or more copies of the gene being present in the genome of the organism. Subsequent mutations in the duplicated gene are important for evolution as it can lead to changes in the function of the protein encoded by the gene. The new protein encoded by the duplicated gene in the dachshund helps in the development of the dog's legs. The RNase I protein encoded by the duplicated gene is different from the RNase | encoded by the original gene because the new protein has a different function, it is expressed in a different tissue, and has a different pattern of expression.

A type of mutation around the Factor X gene that could allow the protein to be expressed in new tissues is a mutation that affects the regulation of the gene. This type of mutation could change the sequence of the gene switch that controls the expression of the gene. In 1-2 sentences, gene duplication events can be important for evolution as they can lead to the creation of new genes that have different functions, allowing organisms to adapt to new environments.

More on gene mutation: https://brainly.com/question/29351113

#SPJ11

The enzyme that facilitates the bicarbonate reaction in erythrocytes is carbonic anhydrase.

Carbonic anhydrase is an enzyme that helps catalyze the reversible reaction of carbon dioxide and water to form carbonic acid and bicarbonate. It is an important enzyme in the human body and is found in the red blood cells of erythrocytes. In the erythrocytes, carbonic anhydrase helps to catalyze the reaction of carbon dioxide, which is produced as a byproduct of metabolism, to form bicarbonate, which is used by the erythrocytes to help maintain the correct pH balance. Carbonic anhydrase also helps to regulate the rate at which bicarbonate is reabsorbed from the red blood cells, allowing for the maintenance of the correct pH balance in the body.

For more such questions on enzyme

https://brainly.com/question/14577353

#SPJ11

When a sessile biofilm (or a part of it) begins to starve or experiences oxygen depletion, cell death occurs.

Learn more about biofilm: https://brainly.com/question/13232627

#SPJ11

The distension of the superficial veins caused by weakened valves is called varicose veins.

Varicose veins are swollen, twisted veins that you can see just below the surface of the skin. They are usually red or blue in color. Common in women, varicose veins can cause pain, fatigue, aching, burning, or itching in the legs. It can also lead to ulceration in the legs.

Varicose veins occur when blood flow reverses and pools in veins, causing them to dilate and stretch. The condition occurs when the walls of the veins weaken and stop functioning properly, allowing blood to collect and stagnate, leading to swelling, pressure, and pain. In this condition, the superficial veins are distended as a result of weakened valves.

For more such questions on superficial veins, click on:

https://brainly.com/question/14191444

#SPJ11

Drugs that target RNA polymerase are direct inhibitors of transcription.

RNA polymerase is an enzyme that helps to create RNA from DNA. It is an essential enzyme that is involved in gene expression by regulating the transcription of DNA into RNA.

RNA polymerase produces a strand of RNA using one strand of DNA as a template. There are many drugs that target RNA polymerase, and they are used as inhibitors of transcription.

Direct inhibitors of RNA polymerase are commonly used to treat cancer, bacterial infections, and viral infections. These drugs act by blocking the enzyme from synthesizing RNA molecules.

By inhibiting RNA synthesis, these drugs can prevent the expression of certain genes, which can be useful in treating various diseases.

To know more about transcription, refer here:

https://brainly.com/question/14136689#

#SPJ11

The superior opening of the larynx is called the laryngeal inlet (or aditus) oriented anteriorly between the thyroid and cricoid cartilages, along the ventricular folds.

The laryngeal inlet is of major clinical importance due to its structure and vulnerability to trauma. It lies at the level of the sixth cervical vertebra and is bounded anteriorly by the epiglottis and posteriorly by the arytenoid cartilages. The inlet is covered by the laryngeal mucosa and is part of the tracheal lumen. It is divided into two parts: the anterior glottis and the posterior laryngeal ventricle.

The anterior glottis is a crescent-shaped area bounded by the false and true vocal folds, and the posterior laryngeal ventricle is a triangular space, surrounded by the arytenoid cartilages and the false and true vocal folds. The aryepiglottic folds, which attach the epiglottis to the arytenoid cartilages, divide the laryngeal inlet into anterior and posterior portions.

The space between the false and true vocal folds is called the interarytenoid space, and the space between the aryepiglottic folds is known as the quadrangular area. The laryngeal inlet serves as the entrance to the larynx and is responsible for protecting the airways and preventing food or other materials from entering the lungs.

For more such questions on larynx

https://brainly.com/question/17774889

#SPJ11

The reactants of glycolysis are glucose, NAD⁺, ATP. Option A, B, and C is correct.

Glycolysis is the metabolic pathway which converts glucose into pyruvate. It is an important process in cellular respiration, which is the process by which cells generate energy from glucose and other nutrients. Glycolysis takes place in the cytoplasm of cells and consists of a series of 10 chemical reactions, which can be grouped into two stages: the energy investment phase and the energy payoff phase.

During the energy investment phase, two ATP molecules are used to phosphorylate glucose, which makes it easier to break down in the subsequent steps. The glucose molecule is then split into two three-carbon molecules called glyceraldehyde 3-phosphate (G₃P).

In the energy payoff phase, the G₃P molecules are converted into pyruvate through a series of reactions that generate four ATP molecules and two NADH molecules. The ATP molecules are produced through a process called substrate-level phosphorylation, in which a phosphate group is transferred from a molecule to ADP, forming ATP. The NADH molecules are produced by the transfer of electrons from G₃P to NAD⁺.

Hence, A.B.C. glucose, NAD⁺, ATP is the correct option.

To know more about glycolysis here

https://brainly.com/question/27178607

#SPJ4

--The given question is incomplete, the complete question is

"Select all of the molecules that are reactants of glycolysis. A) glucose B) NAD⁺ C) ATP D) ADP."--

The male reproductive system includes several structures that work together to produce, store, and deliver sperm. One of the key structures involved in this process is the vas deferens.

The vas deferens, also known as the ductus deferens, is a muscular tube that carries sperm from the epididymis (where sperm mature and are stored) to the urethra. The vas deferens is located within the scrotum and is part of the spermatic cord, which also contains blood vessels, nerves, and other structures.

During ejaculation, the smooth muscles in the wall of the vas deferens contract, propelling the sperm through the duct and into the urethra. From there, the sperm are mixed with seminal fluid from the prostate gland and other accessory glands before being ejaculated from the body.

It is important to note that the vas deferens does not carry sperm from outside the body into the abdominal cavity. Instead, it carries sperm from the testes, where they are produced, to the urethra, where they are ejaculated from the body during sexual activity.

Learn more about  vas deferens here:

https://brainly.com/question/411707

#SPJ4

When red flowered snapdragons are crossed with white flowered snapdragons, all the F1 plants will have pink flowers. If Mendel had used snapdragons instead of pea plants, he would have had difficulty in formulating his principle of incomplete dominance.

Incomplete dominance is a type of inheritance where one allele for a specific trait is not entirely dominant over the other allele. Incomplete dominance is described as a type of gene interaction where both the dominant and recessive alleles are expressed as a blended phenotype in the F1 generation.

Incomplete dominance was first described by Carl Correns, Erich von Tschermak, and Hugo de Vries. They studied snapdragon flowers, which produced a pink color when the dominant red allele was crossed with the recessive white allele. Because Mendel's pea plants only exhibited complete dominance, he would have had difficulty formulating his principle of incomplete dominance if he had used snapdragons instead of pea plants to study genetic inheritance.

Learn more about allele at:

https://brainly.com/question/23516288

#SPJ11

Physical changes that signal the passage from childhood to adolescence are best described as puberty.

Adolescence is a stage that occurs between childhood and adulthood. Its onset is indicated by pubertal development, and its offset is symbolised by parental independence.

Young individuals go through a lot of changes as they transition into physical adulthood during adolescence. The emergence of the secondary sexual features marks the beginning of prepubescent alterations.

To know more about adolescence visit:-

https://brainly.com/question/938949

#SPJ1

The phase of mitosis during which chromosomes line up on the equator of the cell is metaphase. Therefore the correct option is option E.

Mitosis is a cell division process that occurs in most eukaryotic cells. In this process, a parent cell produces two identical daughter cells. Mitosis has five stages: prophase, metaphase, anaphase, telophase, and interphase.

Chromosomes are visible and condense during mitosis, as a result of the coiling of DNA around proteins called histones.Mitosis can be divided into four distinct stages: prophase, metaphase, anaphase, and telophase. During metaphase, the chromosomes line up on the equator of the cell, which is known as the metaphase plate.

The centromeres of the chromosomes are located on the metaphase plate. Chromosomes can then be separated and pulled to opposite poles of the cell during anaphase.

The spindle fibers of the cell, which are microtubules that connect the centrosomes to the chromosomes, are responsible for the separation and movement of the chromosomes. Therefore the correct option is option E.

For such more question on metaphase:

https://brainly.com/question/13627503

#SPJ11

a) When a carrot is submerged in a diluted solution, water will osmosis into the carrot cells. As a result, the cells will become turgid and the carrot's mass will rise.

b) The carrot's inability to alter in mass when submerged in a 0.4 mol/dm3 solution shows that the solute concentration—which includes salts and sugars—within the carrot cells is also 0.4 mol/dm3. There is no net movement of water into or out of the cells at this concentration.

c) This indicates that the carrot and the 0.4 mol/dm3 solution have come to an equilibrium. At this concentration, the passage of water into and out of the cells is balanced, and there is no net gain or loss of water.

d) If the carrot is submerged in a concentrated solution, water will osmotically escape from the cells, plasmolyzing them. The mass of the carrot will shrink as a result.

learn more about osmosis here

https://brainly.com/question/2625460

#SPJ1

The carpal bone that articulates with the radius is the Scaphoid. Therefore, the correct option is b. Scaphoid.

The scaphoid is one of the eight carpal bones located in the wrist. It is also known as the navicular bone or the os scaphoideum. The scaphoid bone is located on the thumb side of the wrist, just below the base of the thumb. It is an important bone for the proper functioning of the wrist joint, as it helps to transfer loads from the hand to the forearm.

The scaphoid bone is shaped like a boat or a crescent moon, with a concave surface facing downward. It articulates with four other carpal bones: the trapezium, trapezoid, capitate, and lunate. The scaphoid also articulates with the radius bone of the forearm, which is important for wrist movement.

Injuries to the scaphoid bone are relatively common, particularly in athletes and individuals who engage in manual labor. Fractures or dislocations of the scaphoid bone can cause pain, swelling, and decreased wrist mobility. Treatment may include immobilization, physical therapy, or in some cases, surgery.

To know more about scaphoid visit :

https://brainly.com/question/7961772

#SPJ1

In this example, crossing over could occur between 2 and 3.

Crossing over is a process that occurs during meiosis, specifically during prophase I of meiosis I. It involves the exchange of genetic material between homologous chromosomes, which are pairs of chromosomes that contain the same genes in the same locations but may have different alleles.

During prophase I, the homologous chromosomes pair up and form a structure called a bivalent or tetrad. Within the bivalent, the chromatids of the homologous chromosomes come into close contact and break at corresponding points. The broken ends then attach to the broken ends of the other chromatid, forming a structure called a chiasma.

Read more on crossing over here:https://brainly.com/question/927405

#SPJ1

The steps involved in scientific method include observation, research question, hypothesis, experiment, result, conclusion, etc.

Steps of the scientific method in this study:

Observation: The researchers observed that college students often experience high levels of stress and that meditation has been suggested as a possible intervention for stress reduction.

Research question: The researchers formulated a research question: Does meditation reduce stress in college students?

Hypothesis: Based on previous research and theory, the researchers formulated a hypothesis: Meditation reduces stress in college students.

Experiment: The researchers designed an experiment to test their hypothesis. They recruited a group of college students and randomly assigned them to either a meditation group or a control group. The meditation group practiced meditation for eight weeks, while the control group did not.

Data collection: The researchers collected data on participants' stress levels before and after the eight-week intervention period.

Results: The researchers analyzed the data and found that the meditation group had significantly lower levels of stress compared to the control group.

Conclusion: Based on their findings, the researchers concluded that meditation is an effective intervention for reducing stress in college students.

Learn more about scientific methods here: https://brainly.com/question/17216882

#SPJ1

Reptiles do not generate their own heat and rely on basking in the sun in order to warm up.

Mammals and birds, however, have the ability to create their own heat. The energy to generate this heat comes from food they eat. Mammals and birds obtain energy from the breakdown of carbohydrates, proteins, and fats in the food they consume. This energy is then used by the body to create heat through metabolic processes such as respiration and digestion. This process helps to maintain the body temperature of these animals, even in cold environments. Heat can also be generated by burning stored body fat which helps to keep the body warm in colder environments. So, the energy that mammals and birds use to generate their own heat comes from the food they eat and the stored body fat.

For more such questions on Reptiles

https://brainly.com/question/21358396

#SPJ11

When an ecosystem is disturbed by fire or toxic chemicals, the effects will be a disturbance that may affect the trophic chain by altering the balance of producer organisms.

The major effects of ecological disturbance include the reduction of natural populations such as plants which represent the primary producers in terrestrial ecosystems, and it may lead to a unbalance in the whole ecosystem's homeostasis.

Therefore, with this data, we can see that the major effects of ecological disturbance include the dramatic reduction in producer organisms.

Learn more about ecological disturbance here:

https://brainly.com/question/1385379

#SPJ1

Radiometric dating and stratigraphy were two important technologies that helped to support Hutton and Lyell's hypothesis that the Earth is much older than previously believed.

Radiometric dating techniques allowed scientists to accurately determine the age of rocks and fossils by measuring the decay of radioactive isotopes. This helped to confirm the geological time scale developed by Hutton and Lyell, which showed that the Earth had undergone many changes over a long period of time. Stratigraphy, the study of rock layers and their relationships to each other, helped to construct a timeline of geological events and determine the relative ages of different rock formations.

To know more about radiometric click here:

brainly.com/question/14799339

#SPJ4

A water-repellent cuticle, stomata that control water evaporation, specialised cells that give stiff support against gravity, and specialised structures that capture sunlight are just a few examples of how plants evolve.

In order for terrestrial plants to grow, seeds are essential. Sexual organs, a multicellular embryo shielded by parental tissue, a vascular transport system, and rhizoids, roots, and root hairs necessary for soaking up nutrients and water are all present. Haploid and diploid generations alternate. The construction and upkeep of developmental programmes required for plants to adapt to life on land rely on the regulation of gene expression for the evolution of morphological variation. The genetic and molecular mechanisms behind morphological variation and plant adaptation to land are still poorly understood, despite advances in these fields.

Learn more about sunlight here:

https://brainly.com/question/1603783

#SPJ1

Different types of photopigments differ from one another based on the specific wavelengths of light they absorb and the color vision they enable.

Photopigments are proteins found in the cone cells of the retina, responsible for detecting light and color vision.

There are three types of cone cells in the retina, each containing a different type of photopigment that responds to different wavelengths of light: blue, green, and red. These photopigments are called opsin and they bind with a chromophore called retinal to form the complete photopigment.

Each type of opsin has a slightly different amino acid sequence, which determines the wavelengths of light it absorbs most effectively, and hence the color vision it enables. For example, the blue opsin absorbs shorter wavelengths of light, while the red opsin absorbs longer wavelengths. When different combinations of photopigments are stimulated by light, the brain can interpret the information to perceive a range of colors. Overall, the differences in the amino acid sequences of the opsin photopigments determine their spectral sensitivity and enable us to perceive different colors.

To learn more about photopigments refer to

brainly.com/question/25853052

#SPJ4

Answer:

Explanation:

don't know

Answer:

(b)

(i)

Here is the labeled diagram of the gill filaments of a bony fish, with the requested arrow and labels:

markdown

Copy code

capillaries

↓

(ii) Š

↑ gill plate

│ water current

│

H L

(ii)

The letter H indicates an area where there is the highest concentration of oxygen in the blood of the gill plate, which is at the end of the capillary bed closest to the water flow. The letter L indicates where there is the lowest concentration of oxygen in the water passing over the gill plate, which is at the end of the gill filament farthest from the water flow.

(iii)

This type of flow is called countercurrent flow. It improves the efficiency of oxygen uptake because it maintains a concentration gradient between the water and the blood across the entire length of the gill filament. As the water flows over the gill filaments, oxygen diffuses from the water into the blood of the capillaries. Because the concentration of oxygen is always higher in the water than in the blood, oxygen continues to diffuse across the entire length of the filament. This ensures that the blood leaving the gill filament at the end closest to the heart has the highest possible concentration of oxygen. If concurrent flow were used, where water and blood flow in the same direction, the concentration gradient between the water and blood would be reduced along the length of the gill filament, resulting in less efficient oxygen uptake.

(please mark my answer as brainliest if it was helpful)