INTRODUCTION:
Germination is the resumption of growth of the embryo plant inside the seed.
Requirements for germination: * proper temperature * the presence of adequate water * oxygen
There are two types of cotyledons: the monocotyledons (“monocots”) and the dicotyledons (“dicots”). Monocots have one cotyledon. Rice and corn are monocots. Dicots have two cotyledons. Lentils, lima beans, and green beans are dicots.*
Germination in Dicots
1. The bean seed is a dicotyledonous and non-endospermic seed.When soaked in water ,the seed swells up,the seed coat is softened and then it bursts.
2.The radicle grows and comes out of the micropyle.It penetrates the soil and forms the primary root.It gives rise to lateral roots which fix the seedling to the soil and absorb water from it.
3.The hypocotyl grows rapidly and comes out of the soil in the form of an arch.The arch gradually straightens up and drags the cotyledons out of the seed coat.The seed coat is either left in the soil or comes out along with the cotyledons and falls off later.The cotyledons opens up in the air and the plumule becomes visible.The cotyledons and the hypocotyl become green.The cotyledons shrivel and fall off.**
RESEARCH QUESTION:How does changing the amount of water will effect the rate of germination.
Hypothesis:As the amount of water used for each plant increases the rate of germination will also increase.But “the presence of adequate water “ is needed for germination so when too much water will used the rate of germination will again get slower.
Materials:
* 25 glasses * 25 lentils * Cotton * Drinking water * Thermometer * Ruler
Independent variable:The amount of water used for each lentil.
Dependant variable:the germination rates of the lentils(by measuring their heights after 10 days.)
Controlled variables: * Temperature of the room(23 celcius) * The amount of light * The amount of oxygen