Tracheids are elongated cells in the xylem of vascular plants that serve to transport of water and mineral salts. It contributes to the transport system and provides structural support.

Only green plants and some other organisms can make food by the process of photosynthesis. In this process, carbon dioxide and water combine in the presence of light to form sugar.

Osmosis is the net movement of solvent molecules through a partially permeable membrane into a region of higher solute concentration. Due to the low water potential and the presence of semi permeable membrane of the root hair cell, water enters the plant by the process of osmosis. This mechanism is responsible for the ability of plant roots to draw water from the soil.

Stomata are minute apertures on plants found typically on the outer leaf skin layer, also known as the epidermis. They consist of two specialized cells called guard cells that surround a tiny pore called a stoma. Their main function is to allow gases such as carbon dioxide, water vapour and oxygen to move rapidly into and out of the leaf.

It is the function of pancreas in our body. All other functions are performed by blood in human body.

Platelets (thrombocytes) are the smallest type of blood cells, which play an important role in blood clotting. When bleeding occurs, the platelets swell and clump together and form a sticky plug, which helps to stop the bleeding.

It is the process of transferring blood or blood based products from one person into the circulatory system of another. Blood transfusions can be life saving in some situations such as massive blood loss due to trauma, or can be used to replace blood lost during surgery. Blood transfusions may also be used to treat a severe anaemia or thrombocytopenia caused by a blood disease.

Active transport is the movement of a substance across a cell membrane against its concentration gradient from low to high concentration. In all cells, this is usually concerned with accumulating high concentration of molecules that the cell needs such as ions, glucose and amino acids. If the process uses chemical energy such as from adenosine triphosphate (ATP), it is termed primary active transport. Secondary active transport involves the use of an electrochemical gradient.

The antigens expressed on the surface of red blood cell determine an individual's blood group. Blood group antigens are either sugars or proteins, and they are attached to various components in the red blood cell membrane.

A venule is a very small blood vessel in the microcirculation that allows blood to return from the capillary beds to the larger blood vessels called veins. Venules range from 8 to100 μm in diameter, and are formed when capillaries unite together. Many venules unite to form a vein.

The tricuspid valve or right atrioventricular valve is present on the right dorsal side of the mammalian heart in between the right atrium and the right ventricle. The function of the valve is to ensure that blood flows from the right atrium to the right ventricle by closing an prevented back flow during ventricle systole.

Blood group O individuals do not have either A or B antigens on the surface of their RBCs, but their blood serum contain IgM anti A antibodies and anti B antibodies against the A and B blood group antigens. Therefore, an individual of blood group O can receive blood only from a blood group O individual, but can donate blood to individuals of any ABO blood group.

Usually when a plant wilts, it is an indicative of lack of water or moisture . It also occurs due to the presence of some kind of toxin such as introduced by disease or poison. If the soil around the roots of a plant lacks water or the rate of loss of water is faster than the rate of absorption of water, the cells in the plant will contain less water and fail to support the plant. Therefore, it results in dropping of plant parts.

It is the pressure, which is exerted on the walls of the various arteries around the body in between heart beats when the heart is relaxed. Its normal range in adults is 60 to 80 mm Hg.

The deoxygenated blood is pumped from heart to the lungs. When we breathe in air, it contains oxygen. The gases dissolved in the alveoli of the lungs are passed through the membrane of the alveoli into the capillaries. In the capillaries, the red blood cells containing haemoglobin will bind to the oxygen molecules thus making the blood oxygenated again.

Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels. It is measured in millimeters of mercury (mmHg). During each heartbeat, the blood pressure varies between a maximum (systolic) and a minimum (diastolic) pressure. A healthy person has a blood pressure below 120 over 80 (120/80).

It is the vascular tissue in plants that conducts sugars and other metabolic products downward from the leaves. Phloem translocates sugars made by photosynthetic areas of plants to storage organs like roots, tubers or bulbs.

The sphygmomanometer is designed to monitor the blood pressure by measuring the force of the blood in the heart where the pressure is the greatest. This occurs during the contraction of the ventricles when blood is pumped from the heart to the rest of the body (systolic pressure). The minimal force is also measured during the relaxation of the heart.

They are white blood cells present in the vertebrate immune system. The three major types of lymphocytes are T cells, B cells and natural killer (NK) cells. T cells are involved in cell mediated immunity,whereas B cells are primarily responsible for humoral immunity. NK cells help in defending the host from both tumors and virally infected cells.

Xylem is one of the two types of transport tissue in vascular plants for the transport of substances in plants. It transports water and soluble mineral nutrients from the roots throughout the plant.