What are different regions of body in insects.
The body in insects has three distinct regions: head, thorax and abdomen Head, is usually vertical to the body and jaws are ventrally placed. A pair of antennae and compound eyes are present on head. The thorax has three segments in which are present three pairs of jointed legs and in many one or two pairs of wings. Abdomen has varying number of segments.
How locomotion occurs in arthropods?
The arthropods show active and swift movements. They swim, crawl or fly depending upon the habitat they occupy. The organs of locomotion are paired legs and paired wings.
What is metamorphosis? or Define the term metamorphosis.
This is an abrupt change of form or structure during the life cycle of insects during which egg passing through different stages becomes edult There are two types of metamorphosis. Complete and incomplete in complete metamorphosis, the egg develops into larva which is converted into motionless pupa that develops into an adult e., house fly. If any stage (tarva / pupa) misses, then it is called incomplete metamorphosis.e.g., cockroach.
What is nymph? or Describe incomplete metamorphosis.
In some primitive insects (Cockroach) the metamorphosis is incomplete. The larva resembles aduit and called nymph or instar. It lives in the same habitat as adult.
Give examples of class Insecta.
House fly, mosquito, butterflies, moths, wasps and beetles etc. are examples of class Insecta.
What are Arachnida? Give examples of class Arachnida.
Arachnids are arthropods with two body segments eight legs no wings or antennae and are not able to chew Scorpions, sp ders mites and ticks are examples of class Arachnida.
Give examples of class Myriapoda.
Centipedes and millipedes are examples of class Myriapoda.
What are two of the main achievements of arthropods?
Two of the main achievements of arthropods are the chitinous exoskeleton and locomotary mechanism.
What is moulting or ecdysis? How it is beneficial to arthropods? or Explain term ecdysis.
The process of shedding skeleton is called moulting or ecdysis. In the young arthropods as in the insect larvae chitin is shed from time to time, allow growth of the larva.
How insects are involved in the spread of diseases? or Describe briefly two harmful insects. Give examples.
Female mosquito of genus Anopheles transmits plasmodium that causes ‘malaria fever in man. The Tse-Tse fly of African countries transmits. Trypanosoma, the cause of sleeping sickness and skin diseases. common House Fly carries disease causing organisms to contaminate foor etc., and causes cholera, hepatitis etc.
Give examples of class Cephalopoda.
Loligo, Sepia and Octopus are examples of class Cephalopoda.
Differentiate between haemoglobin and haemocyanin
Haemoglobin is a respiratory pigment red in colour, found in the word of annelids and chordates while haemocyanin is also a respirator, pigmooit blue in colour, present in the blood of molluscs.
Differentiate between Cephalopoda and Gastropoda.
Cephalopoda and Gastropoda are classes of Phylum Mollusca. Gastopcds are asymmetrical and their body is covered with usually coileci one pie shell. Cephalopods are bilaterally symmetrical with dorso-ventral body. The shell is much reduced and internal.