Animal Kingdom

Question 1

How are cells arranged in sponges?

Answer 1

Sponges exhibit a cellular level of organisation (the cells are arranged as loose cell aggregates)

Question 2

How are cells arranged in coelenterates?

Answer 2

These cells are more complex. The cells performing the same functions are arranged into tissues. (Tissue level of organisation)

Question 3

Which organism exhibits the organ level of organisation?

Answer 3

Platyhelminthes and other phyla.

Question 4

Explain the organ level of organisation

Answer 4

Here, tissues are grouped together to form organs. Each organ specialises in one function.

Question 5

What are the types of circulatory systems?

Answer 5

Open type and closed type

Question 6

What is open type?

Answer 6

The blood is pumped out of the heart and the cells and tissues are directly bathed in it.

Question 7

What is closed type?

Answer 7

Blood is circulated through a series of vessels of varying diameters.

Question 8

Describe asymmetrical with an example.

Answer 8

Any plane that passes through the centre and does not divide them into equal halves is called asymmetrical. Example: Sponges

Question 9

What is radical symmetry?

Answer 9

Any plane passing through the central axis of the body that divides the organism into two identical halves is known as radical symmetry.

Question 10

What are some examples for radical symmetry?

Answer 10

Coelenterates, ctenophores, echinoderms

Question 11

What is bilateral symmetry?

Answer 11

In bilateral symmetry, the body can be divided into identical left and right halves in only one plane.

Question 12

Give some examples of bilateral symmetry.

Answer 12

Annelids, Arthropods

Question 13

What is a diploblastic animal? (With example)

Answer 13

Animals in which the cells are arranged in two embryonic layers , an external ectoderm and an internal endoderm, are called diploblastic. Example: Coelenterates

Question 14

What is mesoglea?

Answer 14

Mesoglea is the unidentified layer present in between the ectoderm and the endoderm.

Question 15

What are triploblastic animals?

Answer 15

In these animals, the developing embryo has a third germinal layer, mesoderm, in between the ectoderm and the endoderm. Eg: Platyhelminthes to chordates

Question 16

What is the coelom?

Answer 16

The body cavity which is lined with the mesoderm is called the coelom. Animals that possess the coelom (like annelids, molluscs, arthropods, echinoderms, hemichordates and chordates) are called coelomates.

Question 17

Explain the pseudocoelom.

Answer 17

The body cavity in some animals is not lined by the mesoderm, instead, the mesoderm is present as scattered pouches between the ectoderm and the endoderm. Animals that possess them are called pseudocoelomates (Example: Aschelminthes).

Question 18

The animals in which the body cavity is absent are called ______.

Answer 18

Acoelomates. (Example: Platyhelminthes)

Question 19

What is segmentation?

Answer 19

In some animals, the body is externally and internally divided into segments with a serial repetition of at least some organs. (Ex: Earthworm)

Question 20

What is metamerism?

Answer 20

In earthworms, the body shows this pattern called metametric segmentation and this phenomenon is known as metamerism.

Question 21

Notochords?

Answer 21

Notochords are mesodermally derived rod-like structures, formed on the dorsal side during embryonic development in some animals. Animals with notochords are called chordates, and those who do not are called non-chordates. (Example: Porifera to echinoderms)

Question 22

Members of which phylum are commonly known as sponges?

Answer 22

Porifera

Question 23

Describe porifera.

Answer 23

They are generally marine and asymmetrical animals. These are primitive multicellular animals and have cellular level of organisation.