five structural level of organization

The respiratory system starts with the nose that encloses the nasal cavity . The nasal cavity opens outside through the openings called the nostrils . The nasal cavity is divided into two portions by a cartilagenous septum and is lined by fine hairs that filter the dust particles from the air...

Organic cyanides has a triple bond between the C and N atoms i.e., one sigma and two pi bonds are present. Thus nitrogen here is sp hybridized. The C-C N bond angle is 180 o . Bond length of then the triple bond C N is shorter than the double bond C=N in imines and C - N single bond in am..

The human heart is a muscular, cone-shaped, hollow organ about the size of a fist (about 12cm in length and 9cm in breadth). The heart is situated behind the sternum, between the lungs in the thoracic cavity. The heart is tilted slightly such that its apex is towards the left side. Ex..

Different types of tissue may together become organised into an organ for some specific function. E.g., a gland is an organ meant for secretion. In a gland there are four tissues - Epithelium (for secretion) Muscular tissue (for contraction of the gland) Connective tiss..

>Body fat - There is redistribution of fat to deeper parts of the body from the skin. In women, fat is generally stored in the hips and thighs, while in men it is stored in the abdominal area. Retention of water - The capacity of body cells to retain water decreases. This makes the skin dry and wri..

.4 - Collagen triplex helix In globular proteins e.g., haemoglobin the polypeptide chains consist partly of helical sections which are folded about the random cuts to give it a spherical shape. The primary, secondary and tertiary and quarternary levels of haemoglobin structure a..

Summary - The cells of all living organisms consist of protoplasm, which is bound by a cell membrane. Prokaryotic cells and cells of algae, fungi and higher plants contain a cell wall outside the cell membrane. Some protozoans cells show the presence of a cell coat outside the cell membra..

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In multicellular organisms, cells having a common origin, group to form tissue. The cells in a tissue may be similar in structure to common functions (as in epithelium) or dissimilar in structure performing different functions (as in blood). There are different types ..

These are organs where maturation and proliferation of lymphocytes takes place. Lymphoid organs where T and B lymphocytes mature and acquire their antigen - specific receptors are called Primary Lymphoid organs. Bone marrow (site of B cell maturation) and Thymus gland..