Science Updates

Indicate whether the following statements are True (T) or False (F).

(a) Oviparous animals give birth to young ones. ( )

(b) Each sperm is a single cell. ( )

(c) External fertilization takes place in frogs. ( )

(d) A new human individual develops from a cell called gamete. ( )

(e) Egg laid after fertilization is made up of a single cell. ( )

(f) Amoeba reproduces by budding. ( )

(g) Fertilization is necessary even in asexual reproduction. ( )

(h) Binary fission is a method of asexual reproduction. ( )

(i) A zygote is formed as a result of fertilization. ( )

(j) An embryo is made up of a single cell. ( ) read less

- Breast begin to develop for girls.

- Boys facial hair, moustache, beard.

- Both boys and girls hair grow underarms in the region above the thigh or the pubic area.

(a) wet marble floor, dry marble floor, newspaper and towel.

(b) newspaper, towel, dry marble floor, wet marble floor.

(c) towel, newspaper, dry marble floor, wet marble floor

(d) wet marble floor, dry marble floor, towel, newspaper read less

When an object starts moving from the state of rest, it is called static friction.

The force required to keep the object moving with the same speed is called sliding friction.

When the box starts sliding, the contact points on its surface do not get enough time to lock into the contact points on the floor. So sliding friction is less than static friction.

The bulb does not glow in the setup shown in Fig. 14.10. List the possible reasons. Explain your answer?

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If the current through the circuit is weak, then the filament does not get heated sufficiently, and it does not glow. Though the material may conduct efficiently, it may not conduct as a metal. As a result, even though the circuit is complete, it may not get sufficient current to glow. The solution is non conducting.