Biology

Invertebrate Zoology

634 Questions

Invertebrate zoology covers the anatomical and physiological characteristics of animals without backbones, focusing heavily on insects, earthworms, and other arthropods. These questions explore structural components like respiratory organs and excretory systems. This topic forms a crucial part of the biology section in various competitive exams.

Cockroach anatomyEarthworm organsInsect ordersRespiratory organsExcretory organs

Invertebrate Zoology Questions

Multiple choice

Which among the following statements regarding the life cycle of roundworm Ascaris lumbricoides is incorrect?

  1. First appearance of eggs in stools is within 60–70 days.

  2. Some patients may have pulmonary symptoms or neurological disorders during migration of the larvae.

  3. Adult worms have a lifespan of 1–2 days.

  4. The eggs can survive potentially for 15 years.

  5. The eggs have a characteristic oval shape.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Adult worms have a life-span of 1–2 years which means that individuals may be infected all their lives as worms die and new worms are acquired.

Multiple choice

Directions: The first and the last sentences of the passage are numbered 1 and 6, respectively. The rest of the passage is split into four parts named A, B, C and D. These four parts are not given in their proper order. Read the sentences and find out which of the following combinations is correct.

  1. Silkworms are actually a type of caterpillars that spin silk cocoons around themselves after they turn approximately 1 month old. A. The silk that is used in forming these cocoons is actually hardened silkworm saliva that is secreted from the silkworm's mouth along with the silk. B. Actually, a small spinneret located on the silkworm's lip is used to excrete the silk that they use to form their cocoon. C. At this point, it will then take silkworms approximately 3 days to spin their cocoon around themselves. D. Whenever they are finally ready to start spinning their cocoon, they will stop eating any food and then they will turn yellowish.
  2. If their threads are disturbed by anything, the silkworm will have to start all over again.

  1. ACDB

  2. BCAD

  3. DCAB

  4. DABC

  5. CABD
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

"They” in D refers to silkworms referred in sentence 1. So, a link is established between 1 and D. “At this point” in C refers to the time when they “stop eating food and ... turn yellowish”. “These cocoons” in A links back to "their cocoon" in C. “Silkworm's mouth” in A links to “silkworm's lip” in B (general to specific detail order). Hence, the correct order is DCAB.

Multiple choice

In earthworm the ovary is situated in the

  1. 10th segment

  2. 13th segment

  3. 14th segment

  4. 18th segment
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In earthworms, the ovaries are located in the 13th segment, which is part of their reproductive anatomy.

Multiple choice

If antennae of prawns are cut then they will:

  1. loose their excretory functions

  2. loose their balancing power

  3. loose their sensory functions

  4. all of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Prawn antennae serve multiple functions: they are sensory organs for touch and chemical reception (taste, smell), and they help with balance and orientation. Cutting them would result in loss of all these functions. Antennae are not primarily excretory organs.

Multiple choice

Miracidium larva is found in the life-cycle of:

  1. tapeworm

  2. roundworm

  3. earthworm

  4. liverfluke
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Miracidium is the ciliated larval stage that hatches from eggs of trematodes like liver fluke. It must infect a snail host to continue the life cycle. Tapeworms have oncosphere larvae, roundworms have direct development, and earthworms are annelids without parasitic larval stages.

Multiple choice

The moth that develops fine filament of silk inside the cocoon is

  1. Bombyx Mori

  2. Yersinnia Pestis

  3. Bacillus Actinia

  4. None of these

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bombyx Mori is the silkworm species that produces commercial silk. It spins a cocoon made of a continuous fine filament that can be 600-900 meters long. Yersinia Pestis causes plague (bacteria), and Bacillus Actinia appears to be a fabricated option.

Multiple choice

Eggs of cockroach give rise to:

  1. Nymph

  2. Caterpillar

  3. Larva

  4. Pupa

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cockroaches undergo incomplete metamorphosis (hemimetabolous development), where eggs hatch into nymphs that resemble miniature adults. The nymphs gradually molt and mature into adult cockroaches. Caterpillars and larvae are part of complete metamorphosis seen in butterflies, and pupa is the stage between larva and adult in complete metamorphosis.

Multiple choice

The chewing and lapping type of mouth parts are found in:

  1. butterfly

  2. honey bee

  3. house fly

  4. cockroach
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Honey bees possess chewing and lapping mouthparts adapted for their feeding habits. They have mandibles for chewing (pollen manipulation, wax molding) and a proboscis formed by galeae for lapping nectar from flowers.

Multiple choice

Locomotion in earthworm was described by:

  1. Gray and lissman

  2. Hyman

  3. K.N. Bahl

  4. Grubbed and Mast
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Gray and Lissman conducted detailed studies on earthworm locomotion, describing how earthworms move through coordinated contraction and relaxation of muscles. This is a factual recall question about the history of zoological research.

Multiple choice

Amphids found upon lips of Ascaris

  1. are organs of smell and chemoreception

  2. secrete saliva

  3. are adhesive organs

  4. secrete proteolytic enzymes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Amphids are paired chemosensory organs located in the lips of nematodes like Ascaris. They function as the primary olfactory and chemoreceptive structures, detecting chemical cues in the environment. They do not secrete saliva, act as adhesive organs, or produce proteolytic enzymes.

Multiple choice

Maggot is the larva of

  1. housefly

  2. mosquito

  3. frog

  4. fleas
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A maggot is the larval stage of a fly, specifically the housefly (Musca domestica) and related species. Houseflies lay eggs in decaying organic matter; the hatching larvae (maggots) feed before pupating into adult flies. Mosquitoes have aquatic 'wriggler' larvae, and frogs/fleas have completely different life cycles.

Multiple choice

Cockroach and other insects possess an

  1. Open type vascular system

  2. Closed type vascular system

  3. No vascular system

  4. Both (A) and (B)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Insects, including cockroaches, have an open circulatory system where hemolymph (insect blood) flows freely through body cavities (hemocoels) rather than being confined to blood vessels. Closed circulatory systems are found in vertebrates like humans and earthworms.

Multiple choice

The modification of hind pair of wings into halteres is the characteristic of

  1. lepidoptera

  2. orthoptera

  3. hemiptera

  4. diptera
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Halteres are club-shaped structures formed from the modified hind wings of flies (order Diptera, meaning 'two wings'). They function as gyroscopic sensory organs that help flies maintain balance during flight. The other orders listed (Lepidoptera - butterflies/moths, Orthoptera - grasshoppers/crickets, Hemiptera - true bugs) all have four functional wings and do not have halteres.