23
What is the difference between cutaneous and pulmonary respiration?
Explanation
In frog respiration takes place via two means, i.e., skin and lungs. Cutaneous respiration occrrs through highly vascular moist skin. It takes place in water as well as land.
Pulmonary respiration through lungs. It takes place outside the water.
24
Special venous connection between liver and intestine and between kidney and intestine is found in frog, what are they called?
Explanation
Special venous connection between liver and intestine is called hepatic portal system and venus connection between the kidney and the lower parts of the frog is called renal portal system.
25
Give the location of hepatic caeca in a cockroach. What is their function?
Explanation
Hepatic or gastric caecae are 6-8 narrow and hollow blind tubules called is present at the junction of foregut and midgut. The hepatic caecae are similar to vertebrate liver, secretes digestive juices and help in the digestion.
26
Frogs are beneficial for mankind, justify the statement.
Explanation
Frogs are beneficial for mankind because they eat insects and thus, protect our crops. They serve as an important link of food chains and hence food web in the ecosystem, thus maintaining the ecological balance. Some countries use the muscular legs of frog as a food source.
27
The body of sponges does not possess tissue level of organisation though it is made of thousands of cells. Comment.
Explanation
The level of organisation in sponges is of cellular level. The cells in sponges do not organise to form tissue, although they possess thousands of independently associated cells. The cells may be solitary or colonial and function more or less independently. The cells show division of labour for performing specialised functions.