Write Major Endocrine Glands.

Question:

Write Major Endocrine Glands.

Answer:

Major Endocrine Glands

Pituitary gland

Enclosed deep within the skull, the pituitary gland is the size of a pea. It hangs on a stalk at the base of the brain. It consists of an anterior portion that produces hormones and a posterior portion that has many neural links. This gland is regarded as the master gland as it controls the functions of all the other glands (such as the adrenal, thyroid glands) in the endocrine system. The pituitary gland stimulates the adrenal gland to secrete cortisol, a steroid hormone controls a range of activities from controlling the body’s metabolism to stimulating blood pressure. The pituitary gland also secretes prolactin, which stimulates the production of milk.

Thyroid gland

The thyroid glands can be found at the front of the neck. It sits low in the throat, between the windpipe. Brownish red, it has blood vessels coursing through it. It secretes hormones that are collectively called thyroid hormones. The most prominent are T3 and T4, which influence the body’s rate of metabolism.

Parathyroid glands

The parathyroid glands consist of four small glands that are located behind the thyroids in the neck. They influence the calcium levels in the body by producing a hormone called Parathyroid Hormone. Sometimes, when the gland produces excess parathyroid hormones, it can have negative effects such as brittle bones and kidney stones.

Adrenal glands

The adrenal glands sit atop the kidneys and are no larger than a walnut. These glands produce over 150 hormones that regulate different functions in the body. The most well known is Adrenaline, which triggers the flight or fight response. In other words, this is a stress hormone that helps the organism to either face a dangerous situation or to avoid it altogether. It does this by:

• Increasing blood sugar levels
• Increasing the blood supply to the muscles, particularly to the limbs.
• Dilating the pupils
• Increasing the heart rate
• Tightening the jaw muscles.

Pancreas

The pancreas is exocrine as well as an endocrine gland that sits behind the stomach. It is roughly 6 inches long and rather flat. The pancreas has two primary roles to play:

• Producing digestive enzymes
• Producing hormones such as insulin and glucagon.

Insulin is produced by the β cells in the pancreas and it helps in regulating the blood glucose levels in the body from getting too high. As we are all aware, the lack of insulin causes type 1 and type 2 diabetes. The hormone glucagon is produced by α cells of the pancreas and it helps the body to prevent the glucose levels from dropping too low. Lack of glucagon leads to hypoglycemia. Another key difference between the two is insulin becomes active when the blood glucose levels are high, and glucagon become active only when blood glucose levels are low.

Gonads

Some glands are specific to males or females. For instance, the ovaries are specific to females and are located in the pelvic cavity. While the testes are specific to males. Ovaries produce estrogen that is important for reproduction and female sex characteristics. Testes produce testosterone that is responsible for male sex characteristics. Also, it results in increased muscle mass and body hair.

Pineal gland

The pineal gland is located between the two halves of the brain. It was also known as the “third eye” for most of history due to its location in the brain and its connection with light.

It produces a hormone known as melatonin which influences the body’s internal clock. Also known as the Circadian Rhythm, it influences the body’s sleep/wake cycle. Its effects are not really noticeable unless the individual is sleep-deprived. Factors such as jet lag, or working the night shift has a more noticeable effect on an individual because Circadian rhythm tends to coincide with the day and night cycle. That’s why individuals who work during the night find it hard to fall asleep during the day, and consequently stay awake for the next night.

What are advantages and disadvantages of Asexual Reproduction? also write example.

Question:

What are advantages and disadvantages of Asexual Reproduction? also write example.

Answer:

Advantages of Asexual Reproduction

Following are the advantages of asexual reproduction:

• Mates not required.
• The process of reproduction is rapid.
• An enormous number of organisms can be produced in very less time.
• Positive genetic influences pass on to successive generations.
• It occurs in various environments.

Disadvantages of Asexual Reproduction

The major disadvantages of asexual reproduction are:

• Lack of diversity. Since the off springs are genetically identical to the parent they are more susceptible to the same diseases and nutrient deficiencies as the parent. All the negative mutations persist for generations.
• Since only one organism is involved, the diversity among the organisms is limited.
• They are unable to adapt to the changing environment.
• A single change in the environment would eliminate the entire species.

Asexual Reproduction Examples

Following are the examples of asexual reproduction:

• Bacterium undergoes binary fission in which the cell divides into two along with the nucleus.
• Blackworms or mud worms reproduce through fragmentation.
• Hydras reproduce through budding.
• Organisms such as copperheads undergo parthenogenesis.
• Sugarcane can be grown through vegetative propagation.

What is Asexual Reproduction? write it's type and characteristics.

Question: 

What is Asexual Reproduction? write it's type and characteristics. 

Answer:

Asexual Reproduction:

Asexual reproduction is a mode of reproduction in which a new offspring is produced by a single parent. The new individuals produced are genetically and physically identical to each other, i.e., they are the clones of their parent.

Asexual reproduction is observed in both multicellular and unicellular organisms. This process does not involve any kind of gamete fusion and there won’t be any change in the number of chromosomes either. It will inherit the same genes as the parent, except for some cases where there is a chance of rare mutation to occur.

Characteristics of Asexual Reproduction:

Following are the important features of asexual reproduction:

1. Single parent involved.
2. No fertilization or gamete formation takes place.
3. This process of reproduction occurs in a very short time.
4. The organisms multiply and grow rapidly.
5. The offspring is genetically similar.

Types of Asexual Reproduction:

There are different types of asexual reproduction:

• Binary Fission
• Budding
• Fragmentation
• Vegetative Propagation
• Sporogenesis

What is the Calorific value? and write its importance.

Question: 

What is the Calorific value? and write its importance.

Answer:

Calorific Value:

Calorific value is the amount of heat energy present in food or fuel and which is determined by the complete combustion of specified quantity at constant pressure and in normal conditions. It is also called calorific power. The unit of calorific value is kilojoule per kilogram i.e. KJ/Kg.

Water vapour is generated in the combustion process and the heat should be recovered by using certain techniques. If the heat contained in the water vapour could be recovered then it has high calorific value. If heat contained in the water vapor could not be recovered when it has low calorific value.

The efficiency of fuel or food mainly depends on the calorific value. If the value is high, its efficiency will also be high. If the value is low, its efficiency would also decrease. Calorific value is directly proportional to its efficiency.

Importance of Calorific Value:

It is very important to have a knowledge of the calorific value of fuel to carry out our day-to-day activities. This knowledge helps us to determine the amount of energy we transport. The gas shippers and suppliers require this information to bill gas consumers. It also helps to determine transportation charges of gas shippers and suppliers.

The human body requires calories to carry out daily activities. Without calories, the body would stop working and the cells in the body would die. But, if people consumed only a specific amount of calories each day, they would lead a healthy life. Too high or too low calorie consumption eventually leads to health problems.

What are Respiratory System Disorders? Also write Factors Affecting Respiratory System Disorders.

Question:

What are Respiratory System Disorders? Also write Factors Affecting Respiratory System Disorders.

Answer:

“Respiratory disorders or diseases are diseases of lungs and human airways that affect human respiration.”

A disorder is defined as a state of irregular functioning of the body. The respiratory system disorders or respiratory diseases are the medical terms used to study about the various types of infections, allergies and other diseases related to the different organs, tissues and specialized cells of the human respiratory system.

The respiratory system mainly consists of the upper respiratory tract, alveoli, bronchi, bronchioles, trachea, pleura, and pleural cavity. The common cold is an example of mild respiratory disorders and other serious and life-threatening respiratory disorders include pneumonia, lung cancer and asthma, influenza, tuberculosis, etc.

Factors Affecting Respiratory System Disorders

There are several factors associated with respiratory system disorders. Few of these factors include:

1. Genetics
2. Allergies
3. Smoking
4. Air Pollution
5. Bacterial and viral infections.

Write Type of Respiratory System Disorders and Causes of Respiratory Disorders.

Question:

Write Type of Respiratory System Disorders and Causes of Respiratory Disorders.

Answer:

Types of Respiratory System Disorders

Respiratory system disorders affect millions of people worldwide. There are three main types of respiratory diseases:

Airway Disease

It affects the bronchial tubes which function by transporting oxygen and other gases in and out of the lungs. In airway disease, the passage for air is reduced, which is associated either with narrowing or blocking of bronchial tubes.

Lung Tissue Disease

Human lungs are covered by a thin tissue layer called the pleura. Due to certain viral or bacterial infections, the structure of the lung tissues are affected, which results in scarring or inflammation of the tissue that enables lungs to expand normally and in turn, makes breathing difficult.

Lung Circulation Disease

This disorder occurs when the blood vessels of the lungs are coagulated, swollen or damaged. This affects the ability of the lungs to receive oxygen and release carbon dioxide. In extreme cases, this disorder may affect the functioning of the heart.

Causes of Respiratory Disorders

Respiratory diseases are caused due to exposure to pollutants, smoking, passively inhaling the tobacco smoke, asbestos, radon, etc.

Respiratory Diseases

Following are the major respiratory disorders or diseases:

Asthma

Asthma is a chronic disease which affects the bronchi and bronchioles of the lungs. It causes difficulty in breathing and followed by severe cough, restlessness, cough and a wheezing sound while breathing.

Asthma might cause due to the following factors:

• Cold air
• Airborne allergens
• Respiratory infections
• Physical activity
• Air pollutants

Chronic Obstructive Pulmonary Disease (COPD)

This includes all the respiratory diseases that cause breathlessness or the inability to exhale. It largely affects people who have been exposed to some sort of smoke. It is a very serious disease and worsens even if you stop smoking.

Emphysema

Emphysema is defined as the chronic disease, reduction of the respiratory surface due to the damage to the lung alveolar walls. It is caused mainly by cigarette smoking. The main symptoms of emphysema include shortness of breath and cough. Emphysema might lead to a loss of elasticity of the lungs.

Emphysema may be caused by the following factors:

• Dust
• Chemicals
• Air pollution
• Smoking tobacco
• Exposure to passive cigarette smoking

Occupational Respiratory Disorders

Occupational respiratory disorders are defined as any disorder which affects the respiratory system by long-term inhalation of chemicals, proteins, and dust. For instance, Asbestosis that is caused by the inhalation of asbestos dust.

Occupational respiratory disorders might happen due to the inhalation of the following substances:

• Fumes from metals.
• Smoke from burning organic materials.
• Sprays of varnish, paint, acids, and pesticides.
• Dust from cotton, silica, coal, drug powders and pesticides.
• Gases from industries. For instance, Ammonia, chlorine and nitrogen oxides.

Sinusitis

It is the inflammation of the mucous membranes in the nasal sinus. The mucous membranes produce mucus that drains into the nasal cavities. The bacterial or viral infections or some airborne allergens cause the inflammation of the mucous membranes.

Lung Cancer

Lung cancer can develop in any part of the lungs. It occurs in the main part of the lungs. The treatment of lung cancer depends upon the type, location and its spread.

Write Cell organelles and its function.

Question:

Write Cell organelles and its function. 

Answer:

Cell Organelles

Cells are composed of various cell organelles that perform certain specific functions to carry out life’s processes. The different cell organelles, along with its principal functions, are as follows:

Cell Organelle and its Functions

Nucleolus

The nucleolus is the site of ribosome synthesis. Also, it is involved in controlling cellular activities and cellular reproduction

Nuclear membrane

The nuclear membrane protects the nucleus by forming a boundary between the nucleus and other cell organelles.

Chromosomes

Chromosomes play a crucial role in determining the sex of an individual. Each human cells contain 23 pairs of chromosomes

Endoplasmic reticulum

The endoplasmic reticulum is involved in the transportation of substances throughout the cell. It plays a primary role in the metabolism of carbohydrates, synthesis of lipids, steroids and proteins.

Golgi Bodies

Golgi bodies are called the cell’s post office as it is involved in the transportation of materials within the cell

Ribosome

Ribosomes are the protein synthesisers of the cell

Mitochondria

The mitochondrion is called “the powerhouse of the cell.” It is called so because it produces ATP – the cell’s energy currency

Lysosomes

Lysosomes protect the cell by engulfing the foreign bodies entering the cell and helps in cell renewal. Therefore, it is known as the cell’s suicide bags

Chloroplast

Chloroplasts are the primary organelles for photosynthesis. It contains the pigment chlorophyll

Vacuoles

Vacuoles stores food, water, and other waste materials in the cell