Pheretima posthuma is highly useful as 
Blood of Pheretima is 
In the blood of earthworm, haemoglobin is dissolved in the plasma. RBCs are absent.
In hot summer and cold winter, the number of malaria cases as well as Anopheles declines, Reappearance of malaria in humid warm conditions is due to 
Malpighian tubules are 
Malpighian tubules are fine, unbranched, yellow tubules that lie more or less free in the haemocoel. They open into alimentary canal. They absorb nitrogenous waste product, thus acts as excretory organs in insects.
Kala-azar and Oriental Sore are spread by 
Sand fly is the vector of Kala azar (Leishmania donovani), causes severe liver infection.
Penguin occurs in 
Penguin is a flightless bird found in colder region like Antarctica.
Ecdysis is shedding of 
Stratum corneum is the outermost, partially cornified layer of scale like cells. Small fragments of this layer are periodically shed off from the body known as ecdysis. The new layer is regularly formed by underlaying stratum germinativum.
Skin is a respiratory organ in 
Skin in fact is a secondary or accessory respiratory organ in frog when frog undergoes the hybernation or aestivation i.e. winter sleep or summer sleep & when it goes into the water for a long.
Earthworm possesses hearts 
Earthworm has 4 pairs of heart i.e., 2 pairs Lateral hearts and 2 pairs Lateral oesophageal hearts present in 7th and 9th and 12th and 13th segments respectively.
Bladderworm/cysticercus is the larval stage of 
Bladderworm or cysticerus larva forms in Tapeworm.
The excretory structures of flatworms/Taenia are
Excretory system of Taenia consists of a pair of peculiar flame cells, which absorb the waste material from the body and discharges it through excretory duct.
Classification of Porifera is based on 
The terms porifera was given by Grant, the phylum includes animals with pores in their body. Its classification based on skeleton or spicules.
Ascaris lumbricoides infection occurs through 
Ascaris enters into the human by eating semi-cooked (improperly) cooked pork contaminated with Ascaris.
Male and female cockroaches can be distinguished externally through 
Sexual dimorphism is found in cockroach. A pair of anal style are present in male cockroach only. Female has broader abdomenal segments.
Metamorphosis of insects is regulated through hormone 
Metamorphosis of insects is regulated through ecdysone hormone.
An insect regarded as greatest mechanical carrier of diseases is 
Musca is the zoological name of house fly which is regarded as mechanical carrier of many diseases. It is very active and keeps on visiting on dirty things and eatables as well
Which one occurs in Echinodermata 
Larval stage of Echinoderms have bilateral symmetry and the adults have radial symmetry, pentamerous i.e., body parts arranged in five or multiples of five.
Kidney of adult rabbit is 
Metanephric kidney is found differentiated into cortex and medulla and duct of such kidney is ureter.
An egg laying mammal is 
Prototherians are egg laying mammals, they share characters with reptiles. e.g., - Duck bill Platypus The Platypus (Ornithorhynchus anatinus) is a semi-aquatic mammal endemic to eastern Australia and Tasmania. Together with the four species of echidna, it is one of the five species of monotremes, the only mammals that lay eggs instead of giving birth to live young. It is the sole living representative of its family (Ornithorhynchidae) and genus (Ornithorhynchus), though a number of related species have been found in the fossil record.
The simplest type of canal system in Porifera is 
Presence of canal system - a network of channels for water transport - is an important feature in sponges. Ascon type of canal is simplest in Porifera which brings in food, oxygen and carries away CO2 and nitrogenous waste.
What is correct about Taenia ? 
The body of Taenia is ribbon like and is divided into segments called proglottids. Each proglottid has one or two sets of male and female reproductive organs.
Ascaris larva is called 
Ascaris larva is also called rhabditiform.
A. Periplaneta americana is nocturnal, omnivorous, household pest. 
R. It is because it acts as scavenger
The cockroach, Periplaneta americana, is a common nocturnal, omnivorous household pest which also acts as a scavenger.
Sound box of birds is called 
Sound box or syrinx is present below trachea which produces sound in birds.
Adult Culex and Anopheles can be distinguished with the help of 
The body of an adult lies more or less parallel to the surface in Culex where as in Anopheles the body lies at an angle of 45° to the surface.