Adaptations
Define Adaptations and Ecology.
Some living organisms develop special features which help them survive better in their local weather conditions. This characteristic of living organisms is called adaptation.
Ecology is the study of relationship of an organism and its environment.
List SI units of length, mass and time.
metre, kilogram, second
differentiate between Hot and Cold sources of light with examples.
Sources which first become hot and then emit light. E.g. Sun , bulb, candle
Sources which emit light with their temperature not getting higher than environmental temperature are called cold sources. e.g. fireflies, LEDs , Fluorescent tubes etc.
Give two adaptations of plants in tropical rainforests.
1) Leaves are grooved , have drip tips to allow excess of rainwater to fall off from their surfaces
2) Since very little sunlight reaches lower vegetations, all smaller plants have larger leaves to absorb maximum sunlight available
Define parallax error.
While measuring the length, the eye should be vertically above the point, at which measurement is being taken. Looking at the point of measurement from a angle will result in an error, calles as parallax error.
Define Bioluminescence
The natural phenomenon in which living organisms are seen to emit light from their body is known as "Bioluminescence"
e.g. fireflies, glowworms, certain algae, jellyfish etc.
List two adaptive features of ducks.
1) webbed feet for swimming
2) oil glands under their tails produce oil that helps in waterproofing their feathers
Define Rotational Motion with 2 examples.
The motion in which a body moves about an axis. In this motion, different parts of body moving in circular path move through different distances in a given interval of time.
e.g. motion of a giant wheel, Motion of earth around its axis.
What is pinhole camera and what is the principle behind it? List the properties of image formed?
A pinhole camera is one of the imaging devices that projects the image of an object on a screen. It works on the principle of rectilinear propagation of light. The image formed is real, horizontally and vertically inverted and diminished in size.
Why do the body tissues in fully submerged plants have numerous air spaces?
to keep the plant light and afloat
Name three different types of motion when Earth moves around the Sun
Periodic , Rotational, Circular
List three basic conditions that lead to formation of shadows.
1) Light source
2) Opaque screen
3) Opaque or translucent object
Name two grasses, three small plants and five animls of grasslands.
Grasses - Andropogon, Koeleria
Small plants: Lupines, milkweeds, coneflowers
Animals: deer, rabbit, mice, foxes, snake , lion etc.
Weight of a sack of rice is 2.5 Quintals. What is its weight in Kilogram?
250 Kg
Define Reflection.
When a beam of light strikes a highly polished surface such as a mirror, it bounes off the surface of the mirror and goes away in a different direction. This bouncing off and change in direction of light on striking a plane mirror is called reflection of light.