GSEB Solutions for Class 9 Science and Technology – Diversity in Living Organisms-II (English Medium)
GSEB SolutionsMathsScience
Exercise 65:
Solution 1.1:
A. Coelenterate
In coelenterates, mesoglea is a jelly like substance present between the ectoderm and the endoderm.
Solution 1.2:
A. Round worm
The common name of Ascaris is round worm. It causes a disease called ascariasis which is an infection of the stomach and the intestine in humans.
Solution 1.3:
D. All the above
Arthropoda are a diverse group of animals that respire through gills, trachea, book lungs or lungs.
Solution 1.4:
A. Flame cell
First excretory organs are found in platyhelminthes class of organisms. They are called flame cells.
Solution 1.5:
D. All three
Frog, salamander and toad are all amphibians and are cold blooded animals.
Solution 1.6:
B. Two
Shark is a cartilaginous fish having a two chambered heart.
Solution 1.7:
C. Urinary bladder
Birds excrete in the form of uric acid instead of urea as in mammals. Hence, they lack a urinary bladder.
Solution 2.1:
Following characters of poriferan animals differ from coelenterate animal
| Poriferan | Coelenterate |
| The animals show cellular organisation. | The animals show tissue level organisation. |
| Tentacles are absent. | Tentacles are present. |
| They have numerous pores and an opening at the top. | They have only one opening through the mouth. |
| Example – Sycon, Spongilla | Example – Hydra, Jellyfish |
Solution 2.2:
The differences between annelid and arthropod animals are as follows:
| Annelida | Arthropoda |
| Respiration in Annelida takes place through the body wall. | Respiration in Arthropoda takes place through gills, trachea, lungs or book lungs. |
| Excretory organs are nephridia. | Excretory organs are green glands or malpighian tubules. |
| Animals are unisexual or hermaphrodites. | In arthropod animals, sexes are separate. |
| Locomotion takes place using setae. | Locomotion takes place using three pairs of jointed appendages. |
| Example – Earthworm, Leech, Nereis | Example – Spider, Prawn, Crab |
Solution 2.3:
| Amphibians | Reptiles |
| Amphibians live in water and also, on land. | Reptiles live on land. |
| Their skin is smooth, slimy, moist and without scales. | Their skin is dry and with scales. |
| Respiration in young ones takes place through gills and in adults, through skin and lungs. | Respiration takes place through lungs |
| Example – Frog, Toad, Salamander. | Example – Lizard, Draco, Turtle. |
Solution 2.4:
Three main characteristics of chordates are:
- Rod like notochord is present at some stage of life.
- A hollow tubular nerve cord is present dorsally.
- Gill-slits are present at some stage of life. All chordates are triploblastic and coelomate.
Solution 2.5:
| Bony Fish | Cartilaginous Fish |
| Endoskeleton is made up of bones. | Endoskeleton is made up of cartilages. |
| Mouth is present at the terminal end of the head. | Mouth is present at the ventral side of the head. |
| Example – Shark, Ray fish | Example – Rohu, Sea horse |
Solution 2.6:
Organisms can be identified on the basis of their differentiating characters. Differentiating characters of following organisms are:
Protozoan – Unicellular organism that lacks differentiation of body parts.
Sponge – Multicellular organism that lacks differentiation of body parts; it has numerous pores on the surface of the body and one opening at the top.
Fish – aquatic animal with a spindle shaped body, showing presence of fins, tail and gill slits.
Round worm – round tube like unsegmented body, having a shiny body surface.
Centipede – small tubular segmented body showing one pair of appendages per body segment.
Snake – tube like small or long body with smooth skin and limbs absent.
Solution 2.7:
Different classes of Phylum Chordata are
- Pisces
- Amphibia
- Reptilia
- Aves
- Mammalia