Which hormone controls the development of female secondary sex characterisrics?​

The special pair in photosystem II is known as P680 because it absorbs 680 nm wavelengths the best.

Photosystems are basically the functional units for the process of  photosynthesis which get defined by a certain organization of the pigment  as well as some association patterns, which perform the very crucial function of the absorption as well as the transfer of the light energy, which basically causes the transfer of the electrons.

The photosystem II basically has a special pair which is known as the P680 and it is named so as it happens to absorbs 680 nm wavelength the best.

To know more about photosystems

https://brainly.com/question/13211869

#SPJ4

The serum protein electrophoresis pattern is consistent with all; cirrhosis, acute inflammation, monoclonal gammopathy and polyclonal gammopathy (e.g., chronic inflammation)

Serum protein electrophoresis is a laboratory technique used to separate and analyze different proteins in the blood. Based on the patterns observed in the electrophoresis results, you can identify various conditions.

By analyzing the serum protein electrophoresis pattern, you can determine which of these conditions is consistent with the results.

Read more about "Electrophoresis": https://brainly.com/question/28709201

#SPJ11

Answer:  So, basiclally what your suppose to do is include 3 examples of  Environmental hazards which include biological, social, chemical, and physical.

Explanation:

Primary productivity refers to the rate at which photosynthetic organisms, such as phytoplankton, convert sunlight into organic matter through photosynthesis. The primary productivity in different latitudes is influenced by various factors such as temperature, nutrient availability, light intensity, and grazing pressure.

In low latitude (tropical) oceans, the primary productivity is limited by nutrient availability, especially nitrogen and phosphorus. The warm waters increase the metabolic rate of organisms and their nutrient demands. However, the availability of nutrients is limited due to the lack of upwelling and mixing of water masses. Additionally, the high light intensity can cause photoinhibition, where excessive light damages the photosynthetic machinery of phytoplankton.

In high latitude (polar) oceans, primary productivity is limited by low light intensity and nutrient availability. The long periods of darkness during the winter months reduce the amount of sunlight available for photosynthesis. Furthermore, the cold waters limit the growth and reproduction of phytoplankton, reducing their overall biomass. However, during the short summer months, the melting of sea ice and mixing of water masses can increase the nutrient availability, leading to a bloom of phytoplankton.

In mid-latitude (temperate) oceans, primary productivity is influenced by the seasonal changes in temperature and nutrient availability. During the spring and summer months, the warming waters and increased light intensity promote the growth and reproduction of phytoplankton. Additionally, the upwelling of nutrient-rich waters from the deep ocean can further enhance primary productivity.

However, during the winter months, the low light intensity and cooling waters can reduce primary productivity. Grazing pressure from zooplankton and other organisms can also limit primary productivity by consuming the phytoplankton.

For more such questions on Primary productivity.

https://brainly.com/question/29941796#

#SPJ11

The Lyme disease bacterium is passed onto humans directly from ticks.

What is the cause of Lyme disease?

Lyme disease is caused by the bacterium Borrelia burgdorferi, which is transmitted to humans through the bite of infected black-legged ticks. Upon diagnosis, treatment typically involves antibiotics or other appropriate medications to help manage the symptoms and eradicate the infection.

The Lyme disease bacterium is transmitted to humans through tick bites. It is commonly carried by deer ticks, which pick up the bacteria when they feed on infected animals like mice and deer. If left untreated, Lyme disease can cause serious health complications. Treatment typically involves a course of antibiotics to eliminate the bacteria. It's important to protect yourself from tick bites by wearing protective clothing and using insect repellent when spending time outdoors in areas where Lyme disease is prevalent.

To know more about Lyme disease, visit:

https://brainly.com/question/15970483

#SPJ11

Beta-oxidation is the process by which fatty acids are broken down in the mitochondria to generate energy. The process is similar for both saturated and unsaturated fatty acids, but there are some differences in the way unsaturated fatty acids are metabolized.

The main difference between the beta-oxidation of unsaturated fatty acids and saturated fatty acids is the presence of double bonds in unsaturated fatty acids. Unsaturated fatty acids have one or more double bonds, which introduce kinks in the fatty acid chain. This makes it difficult for the enzymes involved in beta-oxidation to access the fatty acid chain.

To overcome this problem, the body has specialized enzymes called isomerases and reductases that work to convert the double bonds into a form that can be metabolized by beta-oxidation. Isomerases convert cis-double bonds to trans-double bonds, which are more accessible to the enzymes involved in beta-oxidation. Reductases, on the other hand, reduce double bonds to single bonds, making the fatty acid completely saturated and ready for beta-oxidation.

Learn more about Beta-oxidation,

https://brainly.com/question/29458295

#SPJ4

The main advantages of using molasses for ABE fermentation instead of another type of biomass include all of the following, except its other uses were not vital.

Biomass is organic material that is produced from living or recently living organisms. Examples of biomass include wood, crops, manure, and other plant and animal materials. Biomass is a renewable energy source that can be used to generate electricity, heat, and fuel. It is considered a sustainable energy source because it is produced from renewable resources and can be replenished in a relatively short period of time. Biomass energy has the potential to reduce carbon emissions and can be used to replace fossil fuels. Biomass can be used to generate electricity through combustion, gasification, and anaerobic digestion.

Therefore the correct answer is C.

To learn more about biomass

https://brainly.com/question/2075765

#SPJ1

The correct answer is D. Molasses is a favorable substrate for ABE fermentation because it is readily available, inexpensive, and its other uses are not vital. However, it does not necessarily increase the acetone yield compared to other substrates.

ABE fermentation is a type of fermentation process used to produce solvents such as acetone, butanol, and ethanol. The name "ABE" comes from the initials of these three solvents.

ABE fermentation is a type of batch fermentation process that uses anaerobic bacteria to convert carbohydrates such as sugars, starches, and cellulose into solvents. The process typically involves three stages: acidogenesis, solventogenesis, and sporulation.

Today, ABE fermentation is used primarily in the production of butanol, which is used as a solvent in a variety of industries including chemicals, pharmaceuticals, and textiles. Butanol is also a potential biofuel that can be blended with gasoline or used as a standalone fuel for vehicles.

Learn more about fermentation here:

https://brainly.com/question/31310689

#SPJ1

Addison's Disease, also known by the acronym ADDI, is an endocrine disorder that affects the body's ability to produce hormones, such as cortisol and aldosterone.

This deficiency can cause a variety of symptoms, including fatigue, weakness, weight loss, nausea, vomiting, and low blood pressure. In addition, people with Addison's Disease may experience darkening of their skin, especially in areas exposed to the sun, as well as salt cravings, muscle and joint pain, and changes in mood.

Patients with Addison's Disease need to be closely monitored by their healthcare team and may require hormone replacement therapy. Education and understanding of the disorder is important for people with Addison's Disease, as well as their families or caregivers, as it can help to improve the quality of life and treatment outcomes. It's important to remember that with proper management and treatment, people with Addison's Disease can lead full and healthy lives.

Know more about Addison's Disease here

https://brainly.com/question/29489251#

#SPJ11

The correct answer is: Desiccants and Defoliants. The correct option is (B).

Dessicants and defoliants are used to help with the harvesting of certain crops. Dessicants help to dry out plants, making them easier to harvest, while defoliants cause plants to shed their leaves, simplifying the harvesting process. Although they are not specifically used for pest control, they play an essential role in crop management.

While desiccants and defoliants can be helpful in crop management, they can also have negative effects on the environment and human health if not used correctly.

For example, desiccants can cause soil and water contamination if they are not applied properly or if they are used in excessive amounts. Defoliants can also harm non-target plants and animals if they are not used with care.

Therefore, it is essential to follow proper guidelines and regulations when using these products to ensure their effectiveness and minimize their negative impacts.

To know more about "Pest control" refer here:

https://brainly.com/question/490313#

#SPJ11

Answer:

They differ in location, prehensile tails, nostrils, and behavior.

Explanation:

New World monkeys and Old World monkeys are separated geographically by the Atlantic Ocean, and they also have several physical and behavioral differences.

Some key differences between New World monkeys and Old World monkeys include:

New World monkeys are also generally smaller than Old World monkeys, and often have a different social structure.

Renal corpuscles are made up of Bowman's capsule and glomeruli. All of them are kidney-related components. Controlling the pH balance of your blood, managing blood pressure, and preserving electrolyte balance are just a few of the critical tasks performed by your kidneys.

The filtrate enters Bowman's space (also known as the "urinary space" or "capsular space") after passing through the filtration slits and is located between the visceral and parietal layers. Visceral layer: This layer, which is formed of podocytes, is located slightly above the enlarged glomerular basement membrane. In the mammalian kidney, a nephron's Bowman's capsule serves as the first stage in the filtration of blood to create urine. It is a cup-shaped sack at the start of the tubular portion of the nephron.

To know more about blood pressure, click here:

https://brainly.com/question/4215574

#SPJ4

Newly formed cells in hair are filled with a fibrous protein called keratin. Keratin is a tough and durable protein and provides strength.

It provides strength, resilience, and protection to these structures, helping to prevent damage from external factors such as sunlight, heat, and chemicals.

In hair, keratin is also responsible for creating the texture and shape of individual strands, and variations in the production and organization of keratin can lead to different hair types, textures, and colors.

Learn more about keratin, here:

https://brainly.com/question/28790980

#SPJ4

SDS (Sodium Dodecyl Sulfate) is a commonly used detergent in protein sample preparation for SDS-PAGE (Polyacrylamide Gel Electrophoresis).

SDS Native refers to a method of protein sample preparation where the protein is solubilized in a buffer without reducing agents or SDS. This method maintains the native state of the protein and is useful for analyzing protein-protein interactions.  SDS Reducing involves the use of a reducing agent, such as beta-mercaptoethanol or DTT, to break the disulfide bonds in the protein and denature it. This allows for better separation and visualization of the protein bands on the gel.
SDS Non-Reducing does not involve the use of a reducing agent, which preserves the disulfide bonds and maintains the protein structure. This method is useful for analyzing the oligomeric state of proteins and protein complexes.
Overall, the main difference between SDS Native, Reducing, and Non-Reducing methods is the presence or absence of reducing agents and their effects on the protein structure. The differences between SDS native, reducing, and non-reducing conditions in protein analysis.
1. SDS Native: Under native conditions, proteins maintain their original structure and function. This means that their three-dimensional shape and any protein-protein interactions are preserved. Native conditions are typically used when studying protein function, activity, or when analyzing protein complexes.
2. SDS Reducing: In reducing conditions, a reducing agent (e.g., beta-mercaptoethanol or dithiothreitol) is added to break disulfide bonds within and between proteins. This leads to the linearization of the protein and the separation of protein subunits that were originally held together by disulfide bonds. Reducing conditions are useful for determining the individual subunits of a protein complex and for analyzing proteins with disulfide bonds that can affect their electrophoretic mobility.
3. SDS Non-Reducing: Non-reducing conditions do not include a reducing agent. While the proteins are denatured by SDS (sodium dodecyl sulfate), the disulfide bonds remain intact. This allows for the analysis of proteins with their disulfide bonds preserved. Non-reducing conditions are used when studying protein-protein interactions or the role of disulfide bonds in protein structure.
In summary, the primary differences between SDS native, reducing, and non-reducing conditions lie in the protein structure preservation and the presence or absence of a reducing agent. Native conditions preserve protein structure and function, reducing conditions break disulfide bonds, and non-reducing conditions denature proteins while maintaining disulfide bonds.

For more such questions on  SDS-PAGE (Polyacrylamide Gel Electrophoresis) , Visit:

https://brainly.com/question/23215283

#SPJ11

NADH is the reduced form of nicotinamide adenine dinucleotide as it lacks ion.

The Nicotinamide adenine dinucleotide play critical functions in cellular metabolism, including electron transport during redox processes. the main difference is NADH is reducing in nature while NAD+ is of oxidizing nature.

NADH is formed when NAD+ receives two electrons and a hydrogen ion (H+). This conversion is reversible, with NADH transferring two electrons and a hydrogen ion to other molecules in order to revert to NAD+.

To know more about nicotinamide adenine dinucleotide, visit,

https://brainly.com/question/29668320

#SPJ4

The external intercostal muscles are active during inhalation, as they contract to lift the ribs and expand the chest cavity, allowing air to flow into the lungs.

The internal intercostal muscles, on the other hand, are active during forced exhalation, as they contract to pull the ribs downward and decrease the size of the chest cavity, helping to push air out of the lungs.

During normal, quiet breathing, the internal intercostals are not typically active, as the passive recoil of the lungs and chest wall is sufficient to expel air from the lungs. However, during vigorous exercise or other activities that require increased respiratory effort, the internal intercostal muscles may become active to help expel air from the lungs more forcefully.

To know more about inhalation here

https://brainly.com/question/787576

#SPJ4

Mechanism- the primary consideration/factor of migraines is (trigger points/joints in upper C-spine/changes in blood flow) and it relates to the functioning of the autonomic nervous system

The primary consideration is the presence of trigger points in the upper cervical spine, which includes the neck and base of the head. These trigger points can cause changes in blood flow and the production of pain-causing chemicals in the brain.

This can lead to the development of a migraine headache, which is often accompanied by nausea, sensitivity to light and sound, and other symptoms. When the trigger points are activated, the autonomic nervous system is affected, resulting in the changes in blood flow and production of pain-causing chemicals. This leads to the development of the migraine headache.

know more about migraines here

https://brainly.com/question/28580530#

#SPJ11

The altered sensorium in hyperosmolar hyperglycemic state is caused by severe dehydration, electrolyte imbalances, and reduced blood flow and oxygen supply to the brain due to extremely high blood glucose levels.

Hyperosmolar hyperglycemic state (HHS) is a medical emergency that occurs in individuals with uncontrolled diabetes mellitus, typically in those with type 2 diabetes.

Prompt treatment is crucial to prevent potentially life-threatening complications of HHS.

for such more questions on insulin therapy

https://brainly.com/question/16620320

#SPJ11

The gastrula develops into three germ layers during the third week of embryonic development, which later form various tissues and organs in the body.

During the third week of embryonic development, the gastrula develops into three germ layers: the ectoderm, endoderm, and mesoderm. These germ layers give rise to all the different tissues and organs in the body. The ectoderm forms the skin and nervous system, the endoderm forms the lining of the digestive and respiratory tracts, and the mesoderm forms the muscles, bones, blood vessels, and other internal organs.
During the third week of embryonic development, the gastrula develops into three germ layers: ectoderm, mesoderm, and endoderm. These germ layers will further differentiate and give rise to various tissues and organs in the developing embryo. Here's a step-by-step explanation:
1. The gastrula stage begins with the process of gastrulation, where the embryo transforms from a simple blastula to a structure with three germ layers.
2. The ectoderm forms the outer layer and will eventually develop into the skin, nervous system, and sensory organs.
3. The mesoderm, the middle layer, will develop into muscles, bones, circulatory system, and other connective tissues.
4. The endoderm, the innermost layer, will develop into the digestive system, respiratory system, and other internal organs.
For more such questions on gastrula

https://brainly.com/question/8270805

#SPJ11

Bursae are little fluid-filled sacs that act as a cushion between bones, tendons, and muscles around a joint. They help to minimize bone friction and allow for unrestricted movement.

Bursae form at shearing points in a subcutaneous layer or between deeper tissues like muscle groups and fascia. Tendon sheaths are identical to bursae in that they wrap around bones that are prone to a lot of friction. They contain fluid from the synovial space and help the tendon to move smoothly.

Tendon sheaths are tube-like structures that wrap surrounding tendons that are prone to friction. They contain fluid from the synovial space and help the tendon to move smoothly. When the tendons are at rest, the tendon covers to protect them.

Learn more about bursae and tendon sheaths here:

https://brainly.com/question/13663713

#SPJ4

The non-oxidative branch of the Pentose Phosphate Pathway (PPP) generates important metabolic intermediates that can be used for other cellular processes. In this branch, the conversion of glucose-6-phosphate to ribulose-5-phosphate is accomplished through a series of enzyme-catalyzed reactions that involve several key intermediates.

For more such question on Pentose Phosphate Pathway

https://brainly.com/question/16336697

#SPJ11

In the frog, the two accessory digestive organs that release compounds into the duodenum through the bile duct are the liver and the pancreas.

The liver produces bile, which is stored in the gallbladder and released into the duodenum through the bile duct.

The pancreas also releases digestive enzymes into the duodenum through the bile duct. These enzymes include lipases for fat digestion, amylases for carbohydrate digestion, and proteases for protein digestion.

Together, the liver and pancreas release compounds into the duodenum through the bile duct, contributing to the efficient digestion and absorption of nutrients in the small intestine.

Learn more about duodenum at:

https://brainly.com/question/28162613

#SPJ4

The proliferative phase, also known as the follicular phase, refers to the phase of the menstrual cycle in which the ovarian follicles are stimulated to grow and mature.

This phase typically begins on the first day of menstruation and lasts until ovulation.The length of the proliferative phase can vary from woman to woman and can also vary within the same woman from cycle to cycle. On average, the proliferative phase lasts around 14 days in a 28-day menstrual cycle, but it can range from 7 to 21 days.

Once ovulation occurs, the menstrual cycle enters the luteal phase, during which the ruptured follicle transforms into the corpus luteum, producing progesterone to prepare the uterus for potential implantation of a fertilized egg. If fertilization does not occur, the corpus luteum degenerates, progesterone levels drop, and the menstrual cycle starts again with the shedding of the uterine lining during menstruation.

Menstrual phase: This is the first phase of the menstrual cycle, which starts on the first day of menstrual bleeding and lasts an average of 3-7 days. During this phase, the uterus sheds its inner lining, which results in menstrual bleeding.

Proliferative phase: Also known as the follicular phase, this is the phase of the menstrual cycle in which the ovarian follicles grow and mature under the influence of follicle-stimulating hormone (FSH) from the pituitary gland. This phase typically lasts from day 5 to day 14 of a 28-day cycle, but can vary from woman to woman and from cycle to cycle.

Ovulatory phase: This phase is marked by the release of a mature egg from the ovary, which is triggered by a surge in luteinizing hormone (LH) from the pituitary gland. Ovulation usually occurs around day 14 of a 28-day cycle, but again, can vary.

Luteal phase: After ovulation, the ruptured follicle in the ovary transforms into the corpus luteum, which produces progesterone to prepare the uterus for potential implantation of a fertilized egg. This phase usually lasts from day 15 to day 28 of a 28-day cycle, but again, can vary. If fertilization does not occur, the corpus luteum degenerates, progesterone levels drop, and the menstrual cycle starts again with the shedding of the uterine lining during menstruation.

learn more about proliferative phase here:

https://brainly.com/question/12857355

#SPJ11

In the case of pregnancy, the corpus luteum plays a critical role in supporting the developing embryo until the placenta can take over hormone production.

The corpus luteum is an endocrine gland that produces hormones, primarily progesterone, after ovulation. Progesterone is important for preparing the uterus for implantation and maintaining the uterine lining to support the growing embryo.

for such more questions on Progesterone

https://brainly.com/question/464514

#SPJ11

The study of sensory memory is associated with: George Sperling. The correct option is (c).

Sensory memory refers to the initial stage of memory processing that involves the brief retention of sensory information, such as visual and auditory stimuli. George Sperling conducted several experiments in the 1960s to investigate the nature and capacity of sensory memory, including the iconic memory experiment.

In this experiment, he presented participants with a matrix of letters and asked them to report as many letters as they could remember. In some trials, he presented a tone immediately after the matrix disappeared, indicating which row of letters the participants should report.

Sperling found that participants could recall most of the letters in the cued row, suggesting that sensory memory has a large capacity, but fades quickly if not attended to or encoded further. His work contributed to the understanding of the multi-store model of memory and the role of attention in memory processing.

To know more about "Sensory memory" refer here:

https://brainly.com/question/31181420#

#SPJ11

The first thing to realize is that there are two very different types of cloning: reproductive cloning and therapeutic cloning.

For more such question on cell adhesion

https://brainly.com/question/1444102

#SPJ11

A transmissible disease can be caused by any of the agents listed, including bacteria, viruses, parasites, and protozoa. Therefore the correct option is option A, C, D and E.

Any of the agents listed, including bacteria, viruses, parasites, and protozoa, can produce a transmissible disease. Tuberculosis, for example, is caused by the bacteria Mycobacterium tuberculosis and is a contagious disease.

HIV/AIDS is caused by the virus human immunodeficiency virus (HIV), and it is also a communicable disease. Another example of a parasite-induced disease is malaria, which is caused by the Plasmodium parasite and transmitted by infected mosquitos.

As a result, regardless of categorization, it is critical to take care to prevent the transmission of any infectious agents that can cause transmissible diseases. Therefore the correct option is option A, C, D and E.

For such more question on viruses:

https://brainly.com/question/25236237

#SPJ11

Neurotransmitters are received in the dendron and then cause an nerve impulse to be sent along the axon. What word completes the sentence.

The central nervous system can direct the action of muscles in the body through a mechanism known as Neuromuscular transmission (NMT). Acetylcholine (ACh), a neurotransmitter, is released into a muscle cell's junction as a result of nerve impulses.

An axon releases substances known as neurotransmitters when a nerve impulse reaches the end of the axon. Axon and dendrite of the following neuron form a synapse across which neurotransmitters move. To the dendrite's membrane, neurotransmitters bind.

Following binding, the neurotransmitter causes the target cell to undergo a change or take an action, such as sending an electrical signal to another nerve cell, contracting a muscle, or releasing hormones from a glandular cell.

Learn more about Neurotransmitter:

https://brainly.com/question/1537920

#SPJ4

The skeletal system is the collection of bones, cartilage, ligaments, and other connective tissues that form the framework, or structure, of the body. The skeletal system supports the body, protects internal organs, allows for movement, produces blood cells, and stores and releases minerals like calcium and phosphorus as needed. The bones of the skeletal system are made up of living tissue that constantly undergoes remodeling, and they are held together by joints and strengthened by muscles and tendons.

Learn more about the skeletal system here: https://brainly.com/question/9778649

- The skeletal system does not directly contribute to heat production. However, the bone marrow within the skeletal system plays an important role in the production of heat by generating new red and white blood cells through a process called hematopoiesis. When new blood cells are produced, they generate heat as a byproduct of their metabolic processes.

- Heat production, also known as thermogenesis, refers to the process of generating heat within the body. The human body is constantly generating heat as a result of metabolic processes, such as the breakdown of nutrients for energy. Some organs, such as the liver and muscles, produce more heat than others. Heat production is important for maintaining a constant body temperature, which is essential for the proper functioning of various internal processes.

Learn more about heat production here: https://brainly.com/question/4828635

A) To determine if breeding is taking place beneath all the hair, you can observe the animals' behavior and physical positioning. Mating animals typically exhibit mounting, with the male positioned behind the female.

B) Breeding duration can vary depending on the species, also depend on some factors like age and health of the animals

C)  The volume of ejaculate also varies among different species and it is determined by the size and age of the male, as well as his overall health and reproductive status

A) Breeding in animals with long hair can be difficult to determine, but there are some signs that indicate if it is happening. One of the most obvious signs is if the female animal is receptive to the male's advances. This can be indicated by the female making herself available, standing still, or even making mating calls. Additionally, the male may show signs of arousal, such as mounting or licking the female's genitals.

B) Breeding typically lasts anywhere from a few seconds to a few minutes, depending on the species. However, the actual duration of breeding can vary greatly depending on many factors, such as the size and strength of the male, and the receptiveness of the female.

C) The volume of ejaculate also varies depending on the species, with some animals producing only a few milliliters and others producing several liters.  Factors influencing ejaculate volume include the animal's size, age, and overall health.

Overall, determining if breeding is taking place under all that hair can be challenging, but by observing the behavior of the animals and being aware of the typical breeding patterns of their species, it is possible to make an educated guess as to whether or not they are mating. Additionally, understanding the duration of breeding and the volume of ejaculate can provide insight into the reproductive health of the animals involved.

Know more about reproductive here:

https://brainly.com/question/461781

#SPJ11

An antigen refers to a foreign molecule that causes a specific immune response. Here option A is the correct answer.

Antigens can be any substance that is recognized by the immune system as foreign, including proteins, carbohydrates, lipids, and nucleic acids. These molecules are usually found on the surface of invading pathogens like bacteria, viruses, or parasites, but can also be present in other foreign substances like allergens, toxins, or cancer cells.

When an antigen enters the body, it is recognized by specialized cells called antigen-presenting cells (APCs), which process and present the antigen to other immune cells, such as T cells and B cells.

This presentation triggers an immune response, which involves the activation and proliferation of immune cells that are specific to the antigen. The immune response can take various forms, such as the production of antibodies, the activation of killer T cells, or the release of cytokines that recruit other immune cells to the site of infection.

To learn more about antigens

https://brainly.com/question/31442917

#SPJ4

Complete question:

Which of the following terms refers to a foreign molecule that causes a specific immune response?

a) Hapten

b) Antibody

c) Marker

d) PAMP

e) Antigen