Which one of the following is a growth regulator produced by plants?
Naphthalene acetic acid
Zeatin
2,4-dichlorophenoxy acetic acid
Benzyl aminopurine
In which one of the following, expenditure of energy is required?
Osmosis
Diffusion
Active transport
Passive transport
C.
Active transport
Active transport is the only phenomenon of transportation which uses energy in the form of ATP to pump molecules or ions against a concentration gradient (i.e., low to high concentration). This is mainly carried out by the carrier proteins in the plasma membrane.
Diffusion is the transport of solvent or solute molecules (i.e., across a membrane). Osmosis (i.e., net movement of solvent molecules across a semi-permeable membrane) and passive transport (i.e., movement of biomolecules or other substances across cell membrane) does not require the expenditure of energy for the transportation of molecules or ions.
Juvenile hormone in insect is released from
protocerebrum
corpora cardiaca
corpora allata
thoracic gland
The body of Rohu fish is covered by
cycloid scale, but the tail of homocercal
placoid scale, but the tail of heterocercal
cycloid scale, but the tail of heterocerca
placoid scale, but the tail is homocercal
Management of National Park is controlled by
State Government
Central Government
United Nations
Non-Government Organisations
Objects less than 0.2 m in size cannot be see an under light microscope because
the wave length of visible light is 3900- 7800 Å
only two types of lenses are used
maximum magnifying power of ocular lens is 20 X
maximum magnifying power of objective lens is 100 X