'Cognitive validity' of science curriculum at upper primary stage implies that it should:

Anjali asks the following tasks to be performed by students of Class VII while making an electromagnet (not in correct sequence):

I. Place some pins near the end of a nail.
II. Switch on the current and observe what happens.
Ill. Wind a copper wire tightly around an iron nail.
IV. Connect free ends of the wire to the terminals of a cell.

Which one of the following is the correct sequence of tasks to be performed to achieve the desired result?

Study the following statements about excretory system in humans:

I. Wastes dissolved in water are filtered out as urine in the kidneys.
II. Urine stored in urinary bladder is passed out through the urinary opening at the end of the urethra.
Ill. Ureter carries urine to the urinary bladder.
IV. Useful substances are absorbed back in the blood.
V. Blood containing useful and harmful substances reaches the kidney for filtration.

The correct order of the processes given in the above statements is:

From the organisms given below:

I. Yeasts
II. Bedbugs
Ill. Leeches
IV. Cuscuta
V. Algae
VI. Lice
VII. Mushrooms
VIII. Lichens

Which organisms may be classified in the group of parasites?

In Column-A, names of scientists are given, and in Column-B, some discoveries are given.

The correct match of the names of scientists with their discoveries is: