Tag: earthworm - morphology, integumentary system , respiration and nervous system

Questions Related to earthworm - morphology, integumentary system , respiration and nervous system

Which of the following scientist explained Pheretima posthuma?

  1. Darwin

  2. Bose

  3. K. N. Bahal

  4. C.S. Basu


Correct Option: C
Explanation:

Darwin is known for his famous theory of evolution. Jagdish Chandra Bose is known for his contribution in the field of radio and microwave optics. Pheretima posthuma is the zoological name of an earthworm. Indian scientist, Karm Narayan Bahl (K. N. Bahl) studied the anatomy of Pheretima posthuma (earthworm). 

So, the correct answer is option C.

Read the given statements and select the incorrect one.

  1. In Hydra, all neurons are similar and join to form a nerve net.

  2. In Earthworms, the nervous system consists of a dorsal nerve cord, paired ganglia, and segmental nerves.

  3. Brain is present in insects

  4. Planaria has two nerve cords that join to form rudimentary brain


Correct Option: B

Given is an animal followed by three terms or features. Choose the terms which does not match with the animal.
Earthworm.

  1. Invertebrate

  2. Annelida

  3. Insecta

  4. None of the above


Correct Option: C
Explanation:
Earthworm is an invertebrate and belongs to the annelid phylum whereas Insecta belongs to the arthropods phylum. These two phyla vary with each other by having different skeletons. Annelida contains hydrostatic skeleton whereas arthropods contain chitinous exoskeleton. Hence the correct answer is option C, Insecta.

In earthworm, the spermathecae occur in

  1. 4-7 segments

  2. 5-8 segments

  3. 6-9 segments

  4. 7-10 segments


Correct Option: C
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'.

Chaeta of Pheretima is about

  1. 0.025 mm long

  2. 0.25 mm long

  3. 0.5 mm long

  4. 2.5 mm long


Correct Option: B
Explanation:

Chaeta or cheta is a chitinous bristle or seta found on an insect, arthropod or annelid worms such as the earthworm. They function in locomotion. In Pheretima, chaeta is about 0.25 mm long. 

So, the correct answer is '0.25 mm long'.

Gustatoreceptors of Pheretima are present

  1. In the buccal cavity

  2. In the prostomium

  3. In the peristomium

  4. None of the above


Correct Option: A
Explanation:

Gustoreceptors are found in the epithelial of the buccal cavity,these cells have sensory hair like processes and their nuclei lie below the middle part of the cells. These receptors severs to smell (olfactory receptors) for taste (gustoreceptors). Earthworms can smell different types of decaying food. Hence gustoreceptors are present in the buccal cavity. 

So the correct answer is 'In the buccal cavity'.

Choose the correct answers from the alternatives given.
External ears are characteristics of.

  1. cartilaginous fishes

  2. sea horse

  3. mammals

  4. newts


Correct Option: C
Explanation:

The ear has external, middle, and inner portions. The outer ear is called the pinna and is made of ridged cartilage covered by skin. Sound funnels through the pinna into the external auditory canal, a short tube that ends at the eardrum. These are the characteristic of mammals.

So, the correct option is 'Mammals'.

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


Correct Option: B
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'.

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


Correct Option: B
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'.

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

  1. 60-80

  2. 80-100

  3. 100-120

  4. 120-160


Correct Option: C
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'.