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 zoology earthworm structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

Dorsal pores of earthworm are meant for passage of

  1. Coelomic fluid

  2. Blood

  3. Waste materials

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

Dorsal pores of Earthworm are meant for passage of coelomic fluid which is milky in color and consists of plasma and four types of nucleated corpuscles, namely, phagocytes, nucleated cells, monocytes, and chloragogen cells. When the worm burrows in soil, its posterior muscles contract, forcing the coelomic fluid towards the anterior end.  The anterior end grips the substratum and setae act as anchors on the soil and then the earthworm moves.

So the correct answer is "Coelomic fluid".

Multiple choice zoology earthworm structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

The segment of earthworm in which mouth is situated is called

  1. Prosoma

  2. Prostomium

  3. Peristomium

  4. Prosegment
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • Earthworm lack distinct head. The first segment at the anterior end of the body is called peristomium or buccal segment which bears crescentic mouth.
  • Peristomium bears a fleshly lobe-like structure called prostomium which hangs over the mouth ventrally. 
So, the correct option is 'Peristomium'.

Multiple choice zoology earthworm structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

Choose the wrongly matched pair regarding the position of reproductive structures in earthworm.

  1. Testes - 10$^{th}$ and 11$^{th}$ segments
  2. Spermathecae - 6$^{th}$ to 9$^{th}$ segments
  3. Male genital pore - 9$^{th}$ segment
  4. Ovaries - Inter segmental septum of 12$^{th}$ and 13$^{th}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

1. Testes are in two pairs, white and lobed, located in 10th and 11th segment.

2. Spermathecae are in 4 pairs in each of 6$^{th}$, 7$^{th}$, 8$^{th}$, 9$^{th}$ segment and they store spermatozoa during copulation.
3. Male genital pore is found in one pair located in 18$^{th}$ segment. Sperm produced in the testes is pass out through male genital pore.
4. A pair of small, whitish and lobulated ovaries are located in inter segmental septum of 12$^{th}$ and 13$^{th}$ segments, on either side of ventral nerve cord.
So, the correct option is 'Male genital pore - 9$^{th}$ segment'.

Multiple choice zoology earthworm structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

The structure in earthworm which serves as a wedge to force open cracks in the soil is 

  1. Peristomium

  2. Setae

  3. Typhlosole

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

1. The first segment of the earthworm body is called peristomium or buccal segment which bears crescentic mouth. It bears a fleshly lobe-like structure called prostomium which hangs over the mouth ventrally. It is called the boring part as it bores in soil.

2. Setae are locomotory organs of earthworm.
3. Typhlosole enhances the intestinal absorption area in earthworms.
So, the correct option is 'Prostomium'.

Multiple choice zoology earthworm structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

In earthworms setae are present in all segments except 

  1. First and the last segments

  2. First segment

  3. Clitellum and last segments

  4. First clitellum and last segments
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Setae are the locomotory organ of earthworm.
  • Each segment except first (peristomium), last (pygidium) and clitellum bears setae.
  • The number of setae are 80-120 per segments.
So, the correct option is 'First, clitellum and last segments'.
Multiple choice zoology earthworm structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

The first body segment of earthworm is 

  1. Peristome

  2. Peristomium

  3. Protostomrum

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

The body of earthworm is made of about 100-150 segments. Segmentation help the earthworm move. Each segment or section has muscles and bristles called setae. The first segment is called peristomium.
So, the correct option is 'peristomium'.

Multiple choice zoology earthworm structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations
Setae help in locomotion in earthworm but are not uniformly present in all the segments. They are present in

  1. 1st segment

  2. last segment

  3. clitellar segment

  4. 20th-22nd segment
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In each body segment of earthworm, except the first, last and clitellum, there are rows of setae, embedded in the epidermal pits in the middle of each segment.

Multiple choice zoology environmental science structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

What is common between earthworm and Periplaneta?

  1. Both have red coloured blood.

  2. Both possess anal styles.

  3. Both have Malpighian tubules.

  4. Both have segmented body.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Both earthworm (annelid) and Periplaneta (arthropod) have segmented bodies. In earthworm, the body is metamerically segmented while in Periplaneta, it is externally segmented.

Multiple choice zoology environmental science structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

Which one of the following correctly described the location of some body parts in the earthworm Pheretima ?

  1. Two pairs of accessory glands in 1618 segments
  2. Two pairs of testes in $10^{th} and 11^{th}$ segments.

  3. Four pairs of spermathecae in 47 segments
  4. One pair of ovaries attached at inter segmental septum of $14^{th} and 15^{th}$ segments.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In Pheretima, testes are located in segments 10 and 11, which is accurate anatomical positioning. Option A incorrectly states 1618 segments instead of 16-18. Option C incorrectly states 47 instead of 5-7 segments for spermathecae. Option D incorrectly places ovaries at 14-15 segments instead of 13.

Multiple choice zoology earthworm structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

Match the following and choose the correct answer.

(A) Hermaphrodite (i) Produces blood cells and haemoglobin
(B) Direct development (ii) Testis and ovary in the same animal
(C) Chemoreceptor (iii) Larval form absent
(D) Blood gland in earthworm Sense of chemical substances

  1. A- (ii); B- (iii); C- (iv), D- (i)

  2. A- (iii); B- (ii); C- (iv), D- (i)

  3. A- (i); B- (iii); C- (ii), D- (iv)

  4. A- (ii); B- (iv); C- (iii), D- (i)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

(A) Hermaphrodite - Testis and ovary in the same animal

(B) Direct development - Larval form absent.
(C) Chemoreceptor - Sense of chemical substances
(D) Blood gland in earthworm - Produces blood cells and haemoglobin.
So, the correct answer is (a).

Multiple choice zoology earthworm structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

Earthworm and cockroach are ------- in habit.

  1. nocturnal

  2. diurnal

  3. annual

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

  • Animals that are active at night are said to be nocturnal. Cockroaches and earthworm prefer to live in dark places during the day and they are active only at night. 
  • Diurnal animals remain active during the day. E.g: mammals, birds and reptiles.
  • Annual changes in the behaviour of animals are seen due to the changing cycles of day length, annual variability of rainfall etc.
  • Seasonal changes in behaviour occur due to seasonal variations which may cause local climate change, changes in the availability of food etc. E.g: seasonal migration of birds.
So, the correct option is 'nocturnal'.

Multiple choice zoology earthworm structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

In earthworm, the spermathecae occur in

  1. 4-7 segments

  2. 5-8 segments

  3. 6-9 segments

  4. 7-10 segments
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Spermatheca is four pairs, one pair each in the segments 6$^{th}$, 7$^{th}$, 8$^{th}$, and 9$^{th}$ situated ventrolaterally. These are also called seminal receptacles as they store the spermatozoa from another worm during copulation. 

So the correct answer is '6-9 segments'.

Multiple choice zoology earthworm structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

Choose the correct answers from the alternatives given.
The chitinous bristles that earthworms use to anchor themselves in the earth and pull themselves along are:

  1. aortic arches

  2. setae

  3. parapodia

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

An earthworm has 100 to 150 body segments, each having muscles and bristles. An earthworm's setae are so tiny, they're almost invisible. He uses them to anchor himself while navigating in the soil, or when a bird is trying to pull him from the ground. The setae is a stiff structure resembling a hair or a bristle, especially in an invertebrate.

So, the correct option is, 'setae'.

Multiple choice zoology animal diversity - i (inverterbrate phyla) structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

Choose the correct answers from the alternatives given.
When an earthworm secretes a slime layer to receive eggs and sperm and form a cocoon, this secretion is produced by the:

  1. peritoneum

  2. clitellum

  3. nephridium

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

The clitellum is a thick, saddle-like ring found in the epidermis (skin) of the worm, usually with a light-coloured pigment. To form a cocoon for its eggs, the clitellum secretes a viscous fluid. This organ is used in sexual reproduction of some annelids such as earthworms. 

So, the correct option is, 'clitellum'.

Multiple choice zoology earthworm structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

Somites/metameres/segments present in the body of earthworm are

  1. 60-80

  2. 80-100

  3. 100-120

  4. 120-160
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Earthworms are segmented and are externally covered by rings that encircle the body. Earthworm is divided into segments 100-200 segments similar segments called somites or metameres. Segments are separated from each other by distinct ring-like grooves. External segmentation corresponds to the internal segmentation of the body. Each segment of the group of segments can become specialized to perform a particular function.

So the correct answer is '100-200 segments'.