Questions

The weight of the man mg is acting on the floor. As the lift is moving up with an acceleration, say a, the man too in it is having this acceleration. The force producing this acceleration is ma. By Newton's third law, this force will have an equal reaction pressing the floor equal to ma. Therefore the total resultant reaction on the floor is mg+ma = m(g+a) which is mg, the weight of the man. So (a) is correct.

Passive transport Process includes all other process like facilitated diffusion, osmosis and diffusion of a solute across a membrane.

Savannas are home to a wide diversity of animals.

Many animals of the savanna migrate throughout the year, searching for food and water. Many of the droughts are seasonal and hit one area before another, so animals are constantly following the rains.

Hence, Rain fall is what often governs animal migration on savannas.

DRAM is a Volatile random-access memory (VRAM).

Volatile random-access memory (VRAM) is random-access memory that retains its information when power is turned on.

Examples of volatile memory are primary storage (typically dynamic RAM, DRAM), and fast CPU cache memory (typically static RAM, SRAM, which is fast but energy-consuming and offer lower memory capacity per area unit than DRAM).

Non-volatile random-access memory (NVRAM) is random-access memory that retains its information when power is turned off.

Examples of non-volatile memory are flash memory (used as secondary memory) and ROM, PROM, EPROM and EEPROM memory (used for storing firmware such as BIOS).