Tag: animal diversity - i (inverterbrate phyla)

Questions Related to animal diversity - i (inverterbrate phyla)

In earthworm, neurons are

  1. Sensory

  2. Motor

  3. Mixed

  4. None of these


Correct Option: C
Explanation:

The neurons in the earthworm are myelinated so they are covered with insulating fats. The neurons in earthworm are sensory in nature as well as motor and adjuster or associated neurons. Sensory carries the information from the brain while the motor carries the impulse back to the effector organs.

So, the correct answer is option C.

Which of the following statements is incorrect about the nervous system earthworm?
  1. Nervous system is basically represented by ganglia arranged on ventral nerve cord

  2. In 3rd and 4th segment, the nerve cord bifurcates and joins the cerebral ganglia dorsally to form a nerve ring.

  3. The cerebral ganglia along with other nerves in the ring integrate sensory input as well as command muscular responses of the body

  4. None of these


Correct Option: A
Explanation:

The nervous system of earthworm consists of cerebral ganglia or bilobed brain present dorsally, sub pharygeal ganglia, circum pharyngial ganglia and ventral nerve cord. 

So, the correct answer is 'Nervous system is basically represented by ganglia arranged on ventral nerve cord'

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

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.
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'.

Ctenophora got their names from

  1. Presence of colloblast cells

  2. Presence of paddle like comb plates

  3. Presence of cnidoblasts

  4. All of the above


Correct Option: B
Explanation:

Ctenophora is a phylum of animals that live in marine waters worldwide. Their most distinctive feature is the combs, which is groups of cilia they use for swimming. They are the largest animals that swim by means of cilia. Generally, the outer surface bears usually eight comb rows, called as swimming plates, which are used for swimming. Comb plates paddle plates in them are arranged circumferentially like seams in a football. 

So, the correct answer is option B.

Ctenophora shows affinities with 

  1. Cnidaria

  2. Aschelminthes

  3. Cephalopoda

  4. Turbellaria


Correct Option: A
Explanation:
Ctenophora is a phylum of marine animals which has a diploblastic body like cnidarians. They consist of a jelly-like substance known as mesoglea between endoderm and ectoderm. Ctenophores also resemble cnidarians in having a decentralised nerve net rather than a brain. Both these groups rely on water flow through the body cavity for both digestion and respiration.
Thus, the correct answer is option A.

Biradial symmetry and lack of cnidoblasts are characteristic of 

  1. Hydra and starfish

  2. Starfish and sea anemone

  3. Ctenophora and Beroe

  4. Aurelia and Paramecium


Correct Option: C
Explanation:

Beroe is also known as the mellon jellyfish and is the most common type of species of phylum Ctenophora. Ctenophora is known to have biradial symmetry. Each of the four parts is identical to the opposite side but different from the adjacent side. Cnidoblasts and nematocysts are absent in Ctenophora and are found in cnidarians. 

Thus, the correct answer is option C.

Comb jellies are placed under the group 

  1. Rotifera

  2. Acanthocephala

  3. Cnidaria

  4. Ctenophora


Correct Option: D
Explanation:

Ctenophora is a phylum of animals that lives in marine water. Their most distinctive feature is the combs and groups of cilia they use for swimming. They are the largest animals that swim by means of cilia.

So, the correct answer is option D.