Which are the parasitic worms?
Some worms are parasitic on men and animals. They are the tape worms,
round worms and the flukes.
Which parasite is the cause of sleeping
sickness? The parasite called
Trypanosome.
What are Hair Worms? Hair worms
are long thread like worms which are unusual in that the larvae are internal
parasites on insects or crustaceans but the adults are free-living.
They may be seen wriggling about in ponds and streams.
What are Nematode worms?
Nematode worms are the Round worms.
What are Round worms? Round
worms are long cylindrical worms that live freely in soil and water.
They are also parasites on plants and higher animals. Each can lay
2,00,000 eggs of a day.
How do the round worms live?
They live on what the animal or man has digested, absorb oxygen from the
animal which has absorbed it from the air.
What are Annelid worms? Annelid
worms are segmented worms. They include Bristle worms, Earth worms and
Leaches.
What are Bristle worms? Bristle
worms, living on sea coasts have long bristles projected all over the
body. The worm has a probiscus armed with jaws to get food.
Why are the Earth worms called the friends of
farmers? The Earth worms use their
segmental muscles to expand and contract the body segments and burrow
through the soil. The holes they make allow water and air to pass into
the soil and hence are good for cultivation.
Which is the longest Earth worm?
The longest known giant earth worm is Microcnaetus rappi found in South
Africa. Its average size is 4ft 6 inches.
Which is the shortest earth
worm? The shortest segmented worm
known is Chaetogaster annandalai which measures less than 0.019 inch in
length.
Which is the only parasite that needs two hosts to
live? There is a group of
parasites which need two hosts to survive. It is a thread like flat
worms which spreads the disease of bithariziasis.
How big is a spider? Some
spiders found in South America and Africa are capable enough to eat
birds. Like other spiders, they do not chew their food, they inject
their digestive juices into the birds and suck out the fluids from their
body.
How many eyes do the spiders
have? Most spiders have eight eyes
in two rows of four.
Why do the spiders produce silk and from
where? The spiders produce silk to
construct webs, funnels and other kinds of traps, to trap their victims and
to make a cocoon in which they enclose their eggs. In the hind part of
a spider is the silk gland.
What do you know about the silk of the
spider? Spiders silk is only about
0.005 mm. (0.0002 inches) in diameter. It is so light that if a single
strand were spun round the world, it would weigh less than 170g.
What are Leeches? Leeches are
blood-sucking worms of fresh and salt water. They suck the blood of
animals.
What are Arachnids? Arachnids
are creatures having eight legs. They have their heads and thorax
fused.
What are the differences between arachnids and
insects? Insects have six legs,
while the arachnids have eight legs. The head and thorax of the
insects are separate while in arachnids they are fused together.
Insects have 3 parts in the body excluding the wings. The arachnids
have only two parts in their body.
Give some examples of Arachnids:
Spiders, Scorpions, Harvestman, Miles and Ticks are arachnids.
Name two common marine
arachnids: The large Horse shoe
crabs and the Sea-spiders are the two common marine arachnids.
What is an Amoeba? Amoeba is a
Rhizopod protozoan with a single cell with pseudopodia. It causes
Amoebic dysentery.
Which parasite causes Malaria?
Malaria is caused by the parasite called plamsodium.
How many species of insects are identified so
far? There are more than 800,000.
What is Petrygota and Apetrygota?
Petrygotas are insects which have wings and Apetrygotas are insects with out
wings.
Which are blood sucking insects?
They are Mosquitoes, blackflies, horseflies, deerflies and green head flies.
How does mosquito suck blood? It
has a probosics which is needle like and can pierce through the skin of
animal and draw blood through it.
Which are the shortest and longest living
insects? The shortest living
insects are mayflies which often live for only 4 to 5 hours. The
longest living insects are the queentermite which live for 15-20 years.
Which is a wingless insect? Bug
is the only insect without wings.
What are the specialities of an insect's
eyes? Most of the insects have
compound eyes, made up of separate units. Each has its own lens.
A creature with complete
metamorphosis: Butterfly.
Which group of insects are called Lepidopetra?
The name 'Lepidopetra' means 'scaly wing'. Butterflies and moths
belong to this group. There are nearly 140,000 species known so far.
What are the specialities of a
Dragonfly? Dragonfly is one of the
largest insects which have slow wing beats but are fast fliers. It has
compound eyes with 30,000 separate behind, above and below.
Which are the heaviest insects in the
world? The heaviest insects in the
world are the Goliath. The beetles found in Equatorial Africa.
Which is the largest butterfly?
The largest butterfly is Queen Alexandra birdwing found in New Guinea.
Which is the insect that hunts
spiders? Usually spiders prey on
insects, but there are some insects like 'tarantula hawk', a wasp which hunt
spiders twice its own size.
Why are the bees dancing? Worker
bees dance on the honey comb to inform other bees that the food containing
flower is being found.
Which is the commonest insect?
The commonest insect is the spring tails.
A creature with colourless
blood? Cocoroach, owing to absence
of haemoglobin, its blood is colourless.
What are Molluscs? Molluscs are
a group of animals. They have soft bodies covered with a hard shell
composed of Calcium Carbonate.
Name some important Molluscs:
Oyster, Clam, Octopus, Mussei, and Snail are the important molluscs.
What are univalves and bivalves?
They are two familiar group of molluscs. Single-shelled animals are
called univalves and those with pairs are called bivalves.
How many species are known? More
than 40,000 species are known so far.
Which Molluscs is poisonus?
Australia's blue ringed octopus, which is found in tropical sea is the most
poisonous mollusc.
Why do oysters makes pearls? The
pearl oyster lives in the sandy bottom of the tropical seas. There
they form pearls as a defensive system against the sand and parasites.
Which snail is poisonous?
A snail named cone-shell found in Indian and Pacific Oceans is one of the
most poisonous sea creatures.
Which molluscs are called
cephalopods? Octopuses and squids
are called so because they have grasping arms that grow out of their head.
Which are the molluscs that have
brain? Octopuses, squids and
cuttle fish have brain.
Which is the only cephalopod that has a complete external
shell? The chambered Nautilus
(which means sailor).
Which is the largest octopus in the
world? The largest known octopus
is Octopus apollyon which is found in North Pacific seas and which weighs
about 25kg.
Which is the largest snail? The
largest known snail is, the African giant snail.
