Wastewater Story — Science STD 7 — Question

Write differences between decomposers and scavengers.

Humans use yeast every day. What is yeast?

Sketch the reproductive parts of a flower.

Boojho wants to know how the male gamete in the pollen grain reaches the female gamete present in the ovule?

Place a piece of bread in a moist and warm place for few days. Observe it after few days. What will you see?
(i) Name the organism that grows on the bread piece?
(ii) What are the thread-like projections called?
(iii) What is the knob-like structure present on the top of thin stem called?
(iv) Which type of reproduction does this organism show?

What is the special feature present in a human heart which does not allow mixing of blood when oxygen-rich and carbon dioxide-rich blood reach the heart?

What are the essential processes animals perform to survive?

The distance between two stations is 240 km. A train takes 4 h to cover this distance. Calculate the speed of the train.

(i) Name the only artery that carries carbon dioxide rich blood.
(ii) Why is it called an artery if it does not carry oxygen-rich blood?

How does the heat from the sun reach us?