Biology - 2

Loop of Henle refers to the absorption of water. The kidneys produce concentrated urine by a complex sequence of events which is known as the counter-current multiplier system. This system resides in the loop of Henle, which is a hairpin loop interposed between the proximal and distal tubules of a nephron. 

Addison's disease is characterised by low blood pressure, muscular weakness, loss of appitite and excessive loss of NaCl in the urine. It occurs due to hyposecretion of adrenal cortex. 

Hay fever (allergic rhinitis) is an allergic reaction to airborne allergens such as pollen, dust mites, or pet dander. It causes symptoms like sneezing, runny nose, and itchy eyes. The other options are not primarily caused by allergic reactions.

The main component of fats in mammals are triglycerides. 

 Edward's syndrome is an abnormality leading to mental deficiency. It is caused by trisomy of chromosome number 18.

Down's syndrome is a trisomic condition on the 21st chromosome which is the result of non disjunction, i.e. failure of synapsed homologous chromosomes to separate during anaphase-I of meiosis. 

Abducens is a purely motor nerve which  orginates form the ventral side of the medulla and supplies to the posterior rectus muscles of the eye ball. 

Filariasis (elephantiasis) is caused by nematode worms Wuchereria bancrofti, Brugia malayi, or Brugia timori. Poliomyelitis is viral, leprosy is bacterial (Mycobacterium leprae), and amoebiasis is protozoan (Entamoeba histolytica).

Albinism is an inherited (hereditary) genetic condition caused by mutations in genes involved in melanin production. It is not a deficiency disease (caused by lack of nutrients), degenerative disease (progressive deterioration), or exclusively sex-linked (though some forms can be X-linked).

Mumps is a viral infection that primarily affects the salivary glands, especially the parotid glands which are the largest salivary glands located near the ears. This causes the characteristic swelling of the cheeks and jaw.

Riccia, a liverwort (Marchantiophyta), has a simple thallus body in which the sex organs (archegonia and antheridia) are embedded. In mosses, ferns, and Azolla, the sex organs are more distinctly structured rather than embedded in the thallus.

In ferns (Pteridophytes), a cluster or group of sporangia on the underside of a frond is called a sorus. The indusium is the protective covering over the sorus. Apophysis is part of the sporangium stalk, and strobilus is a cone-like structure in some plants.

This question has a biological inconsistency. If a moss protonema developed from cells of the capsule wall (which is diploid sporophyte tissue), it would technically be diploid, but protonemata are normally haploid (gametophyte phase) structures. This scenario describes an anomaly called 'diploid protonema' which can occur in rare cases.

Clostridium botulinum, the bacterium that causes botulism, is an obligate anaerobe meaning it requires an oxygen-free environment to grow. It cannot survive in the presence of oxygen, unlike facultative anaerobes which can adapt to both conditions.