Genus represents a group of closely related species of plants or animals.

(a) Deficiency of insulin
(i)  Loss of glucose in urine.
(b) Deficiency of thyroid hormones (thyroxine) during pregnancy in the mother.
(i) Mental retardation.
(ii) Stunted growth
(c) Deficiency of growth hormone during childhood.
(i) Stunted growth.

(a) The first part is the generic name and the second part is the specific name.
(b) Linn indicates Linnaeus, who had first described this species.
(c) Because they are in Latin.

(i) It is a method of naming the organisms, in which every organism is given a scientific name, which has two parts (words); the first is the name of the genus (generic name) and the second part is the name of the species (specific epithet). e.g., Mangifera indica.
(ii) In this, Mangifera is the name of the genus while indica is the name of the species (specific epithet) belonging to the genus Mangifera.

Characters which do not play direct role in sexual reproduction but are basically means of sexual differentiation are called secondary sexual characters. For example, facial hair and deep voice in males and thin voice in females are secondary sexual characters

Phylum:
Phylum comes next to Kingdom in the taxonomical hierarchy. All broad characteristics of an animal or plant are defined in a phylum. For example, all chordates have a notochord and gill at some stage of life cycle. Similarly, all arthopods have jointed legs made of chitin.
Order:
Order further zeroes down on characteristics and includes related genera. For example, humans and monkeys belong to the order Primates. Both humans and monkeys can use their hands to manipulate objects and can walk on their hind legs.
Genus:
Comprises a group of related species which has more characters in common in comparison to species of other genera. We can say that genera are aggregates of closely related species. For example, potato, tomato and brinjal are three different species but all belong to the genus Solanum. Lion (Panthera leo), leopard (P. Pardus) and tiger (P. Tigris) with several common features, are all species of the genus Panthera. This genus differs from another genus Felis which includes cats.
Species:
Taxonomic studies consider a group of individual organisms with fundamental morphological similarities as a species. One should be able to distinguish one species from the other closely related species based on the distinct morphological differences.

The category is a part of overall taxonomic arrangement called taxonomic category. All the categories together constitute the taxonomic hierarchy.
A - Phylum, B - Order, C - Family and D - Species

Jet lag is caused by the disruption of the body cock as it out of synchronisation with the unfarmíliar time zone of the two different parts of the world. The body experiences differentpatterns of light and dark than it is normally used to which disrupts the natural sleep-wake cycle.
Melatonin is a hormone that plays a key role in body rhythms and jet lag. After the sun sets, the eyes perceive darkness and alert the hypothalamus to begin releasing melatonin,which promotes sleep. Conversely, when the eyes perceive sunlight, they tell the hypothalamus to with-hold melatonin production. However, the hypothalamus cannot read just its schedule instantly, it takes several days.
His sleep-wake cycle is disturbed; it is controlled by melatonin.

(i) α-cells secrete glucagon; it increases the level of blood glucose by stimulating glycogenolysis and gluconeogenesis, leading to hyperglycemia.
(ii) β-cells secrete insulin; it enhances cellular uptake and utilisation of glucose and stimulates glycogenesis.
(iii) Thus, the two hormones maintain the glucose homeostasis.

Acromegalyrefersto the severedisfigurement,especially of the face, due to excess secretion of growth hormone in adults.
It may lead to death, if not treated.

Triiodothyronine (T₃) and Tetraiodothyronine (T₄) or thyroxine

(a) Insulin
(b) Thyroid
(c) Thyroid

Species is the lowermost taxonomic category in biological classification. Members of a species are similar in physical characteristics and are able to interbreed.

The number of species of flora and fauna present in a given geographical location is called biodiversity.

The hormones secreted by anterior pituitary and their functions are as follows:
(i) Growth hormone (GH)
It regulates the growth of the body; its excess secretion leads to gigantism and low secretion causes dwarfism.
(ii) Adrenocorticotropic hormone (ACTH)
It stimulates the synthesis and secretion of hormones from adrenal cortex.
(iii) Thyroid stimulatmg hormone ( TSH)
It stimulates the thyroid gland to synthesize and secrete thyroid hormones.
(iv) Follicle stimulatmg hormone (FSH)
(a) Along with the androgens, it regulates spermatogenesis in mole.
(b) In females, it stimulates the growth and development of ovarian follicles and secretion of FSH from them
(v) Luteinismg hormone (LH)
(a) In males, it acts on the Leydig cells of testes and stimulates the synthesis and secretion of androgens, mainly testosterone.
(b) In females, it stimulates ovulation, formation of corpus luteum and secretion of progesterone from it.
(vi) Prolactin (PRI )
It regulates the growth of mammary glands and formation of milk in them during pregnancy.

(a) Hypothalamus - Releasing hormone and Inhibiting hormone.
(b) Pituitary - Growth hormone, Prolactin, Thyroid stimulating hormone, Adrenocorticotrophic hormone, Luteinizing hormone, Follicle stimulating hormone, Melatonin.
(c) Thyroid - Tetraiodothyronine, Triiodothyronine.
(d) Parathyroid - Parathyroid hormone.
(e) Adrenal -  Adrenalin or Epinephrine, Noradrenaline or norepinephrine Corticoids.
(f) Pancreas - Glucagon, Insulin.
(g) Testis - Testosterone.
(h) Ovary - Estrogen, Progesterone.
(i) Thymus - Thymosin.
(j) Atrium - Atrial Natriuretic Factor
(k) Kidney - Erythropoietin.
(l) GI Tract - Gastrin, Secretin, Cholecystokinin (CCK)Gastric Inhibitory Peptide (GIP)

General Rules for Nomenclature:
i) Biological names are generally in Latin and written in italics. They are Latinised or derived from Latin irrespective of their origin.
ii) The first word in a biological name represents the genus.
iii) The second component denotes the species.
iv) Both the words in a biological name, when handwritten, are separately underlined or printed in italics to indicate their Latin origin.
v) The first word denoting the genus starts with a capital letter while the second word denoting species starts with a small letter.