Animal Kingdom Test 14

Nematodes, or roundworms are considered to be part of the phylum Nematoda, also known as Nemathelminthes. Around one third of a nematode's cells are nerve cells called ganglia. The equivalent of a brain; a dense, circular nerve ring surrounding the pharynx located in the anterior part of the organism.

Ascaris lumbricoides is a nematode worm which leads a parasitic life in the intestine of man. Hence it is an endoparasite.
Body is long and round so that it can easily fit in the lumen of the intestine.
Cuticle covering the body protects the worm from digestive juices secreted in the host's intestine.
Ascaris also secretes some antienzymes against digestive enzymes of the host.

An excretory pore lies mid-ventrally just back of the mouth. Rossett cells (one per each canal) are associated with each tube in other species of nematodes. There is no sign of flame cells.

Scientifically, round worms are called as nematodes and they belong to class Nematoda. Hence the study of round worms is referred to as nematology.
So the correct option is C "nematology".

Ascaris worms are a genus of helminths (parasitic worms), meaning that they live off of a host organism, to the detriment of that host. The two most common species are Ascaris suum and Ascaris lumbricoides. While A. suum generally infects pigs, they can infect humans as well.

Ascaris is belongs to Aschelminlthes also known as Roundworms.
And it is known that Aschelminltes are bilaterally symmetrical
triploblastic and Psevdocoelomate.
Hence Ascaris is also Triploblastic.

The excretory canals are said to secrete this urea which is eliminated through the excretory pore; some ammonia and urea are also passed out along with the faecal matters. Observations are also there to suggest that Ascaris Lumbricoides excretes more urea when water is scarce.

Male are female sexes are separate in Ascaris and these roundworms also show sexual dimorphism. Males are smaller than the females and they also have a curved tail with pre and post anal papillae, cloaca and a pair of spicules. Gonads are attached at the genital pore in females and at the cloaca in the male worms.

The round worm (Ascaris) may be regarded as specialized animal and not a degenerated one because of the fact that, it has cuticle over the body wall which is resistant to host's digestive juices which is a parasitic adaptation.

The excretory canals are said to secrete this urea which is eliminated through the excretory pore; some ammonia and urea are also passed out along with the faecal matters. Observations are also there to suggest that Ascaris Lumbricoides excretes more urea when water is scarce.

Ascaris lumbricoides is an ammoniotelic organism that majorly releases its waste as ammonia and a small amount as urea as well. There is a pore in the pharynx of this organism that helps in the excretion of salts from the body in order to maintain the osmotic balance Renette glands are also involved in this process of osmoregulation.
So, the correct answer is Renette cells.

Alimentary canal of ascaris lacks digestive glands and is simple and poorly developed because it receives semi-digested food from the host intestine. Pharynx is muscular, modified for sucking the food. The nervous system is poorly developed.

The mouth of Ascaris is a triradiate aperture located at the anterior end of the body. It is guarded by three lips or labia, one dorsal and two ventroventral as shown in the representative diagram.

The nerve ring, also called a nerve collar, creates a complete and closed loop around the food-entry parts of the animal's anatomy. In a typical molluscan arrangement, these include the cerebral, pedal, and pleural ganglia, with the esophagus passing through the center of the ring. In nematodes, the ring consists of only two to four large associative cells connected to two paired lateral ganglia, two ventral ganglia, and a single unpaired dorsal ganglion.
Among arthropods, the usual arrangement is a single ganglion (the cerebral) positioned above the esophagus, a single ganglion or nerve mass (the subesophageal) below it, and commissures connecting the two in a ring.

In Ascaris Lumbricoides, like other nematodes, sexes are separate, i.e., dioecious and readily distinguishable externally, i.e., sexual dimorphism is well distinct.
The male is smaller in size than the female, its tail is curved, while female’s tail is straight, it bears cloaca and a pair of spicules or penial setae but female possesses anus and spicules absent, male possesses pre- and post-anal papillae which are absent in female. The male system is reduced to a single tube but the female system is double.

In Ascaris, a median central rachis is present in both testis and ovaries from where sperms and ova are formed. 

Therefore, the correct answer is option C.

Sexual dimorphism is a phenotypic differentiation between males and females of the same species.
For example, Ascaris male is smaller than Ascaris female. Thus, the correct answer is option B.

Monadelphous is (botany) having all its stamens within a flower fused together at least partly by the filaments while diadelphous is (botany) having its stamens fused together at least partly by the filaments so that they form two separate bundles, or a bundle and a lone separate stamen.
The correct answer would be Option D. 

Fertilized and unfertilized Ascaris lumbricoides eggs are passed in stool of the infected host. Fertilized eggs are are rounded and have a thick shell with an external mammillated layer that is often stained brown by bile. In some cases, the outer layer is absent (known as decorticated eggs).

If a body cavity which occupies a space between the mesoderm of the body wall and the endoderm of the gut is filled with fluid, it is called as pseudocoelom. An organism containing fluid filled cavity is called as pseudocoelomate.
The body cavity of Ascaris is not covered by mesoderm on all sides. It is covered externally by muscles (mesoderm) but internally the lining of the intestine (endoderm). So, it is regarded as a pseudocoelomate. Thus, the correct answer is option B.

In Ascaris, sexes are separate and can be morphologically distinguished. Male has single testis, unpaired vas deferens, seminal vesicle ejaculatory duct and penial sac with penial setae. Female consists of a pair of ovaries a paired of oviducts, pair uteri and vagina.

Ascaris is an animal genus comprised of intestinal roundworms. Ascaris lumbricoides lives in humans, and ascaris suum in pigs. Although the male and female worms look similar, there are several characteristics that distinguish the two sexes, both externally and internally.

Chenopodium is an herb. Oil made from this herb is used as medicine. Authorities disagree on whether chenopodium oil is the oil of fresh, flowering, and fruiting parts of the plant or seed oil. Despite serious safety concerns, people take chenopodium oil to kill roundworms and hookworms in the intestine.

A pregnancy starts with fertilization, when a woman's egg joins with a man's sperm. Fertilization usually takes place in a fallopian tube that links an ovary to the uterus. If the fertilized egg successfully travels down the fallopian tube and implants in the uterus, an embryo starts growing.