The answer compares the common features of living beings with the specific stages described for plants and animals in the chapter summary.
Similarities: Both plants and animals begin life, grow, develop, reproduce and finally die. Both pass through stages in their life cycles and reproduction continues their kind. Differences: A plant life cycle usually starts with seed germination, followed by growth, flowering, seed production and death. An animal life cycle usually begins with a newborn or egg, followed by stages such as young stage, adult stage, reproduction and death. Some animals, such as mosquitoes and frogs, show major body changes during their life cycles.
Growth and respiration are important characteristics of living beings. Non-living objects do not respire, and true living growth requires respiration.
1. No, No: stone or chair; remark: non-living. 2. No, Yes: an adult human or adult animal that has stopped growing in size; remark: it is living and respires. 3. Yes, No: no living example is possible because living growth needs respiration; a salt crystal may grow in size but it is not a living being. 4. Yes, Yes: a seedling, child or young animal; remark: living beings grow and respire.
Seed germination requires water, air and suitable conditions. Removing moisture during storage prevents seeds from germinating.
Grains and pulses should be stored dry, clean and away from moisture. They should be kept in airtight containers or bags in a cool, dry place. This prevents the availability of water and suitable conditions needed for germination, and also reduces spoilage.
A tadpole lives in water, so a tail is useful for movement. As it develops into a frog, legs become the main organs of movement and the tail disappears.
The tail helps the tadpole swim in water. This helps it move, search for food and escape danger during the aquatic stage of its life cycle.
An object is considered living only when it shows essential life processes. Origin from a living thing does not make a dead or cut part living.
Charan is correct that a wooden log is non-living, but not only because it cannot move. A wooden log does not grow, respire, take food, reproduce, excrete or respond like a living being. Charu is correct that wood comes from a tree, which was living, but the log itself is no longer living after being cut from the tree.
The chapter summary lists the stages of mosquitoes and frogs and notes that significant changes occur during their life cycles.
Similarities: Both mosquitoes and frogs lay eggs, have young stages that live in water, grow into adults and reproduce. Distinguishing features: A mosquito passes through egg, larva, pupa and adult stages. A frog passes through egg, tadpole, froglet and adult stages. Mosquitoes have a pupa stage, but frogs do not. A frog changes from an aquatic tadpole with a tail to an adult with legs that can live on land and in water.
Roots generally grow downward to anchor the plant and absorb water and minerals. Shoots generally grow upward towards light so that leaves can receive sunlight.
After one week, the root would be seen growing downward into the soil and the shoot would be seen growing upward. The drawing should show the root bending down and the shoot bending up even if the seedling was initially placed sideways.
The experiment tests the observation that roots generally grow downward and shoots generally grow upward during germination.
They want to find out whether the direction in which a seed is placed affects the direction of growth of its root and shoot. They will know they are correct if, in all the set-ups, the roots grow downward and the shoots grow upward, even when the seeds are placed in different positions.
Only temperature should be changed while other conditions are kept the same. If germination differs between the sets, temperature has an effect on seed germination.
Take three sets of equal numbers of the same type of seeds on moist cotton. Keep one set in a cool place, one at room temperature and one in a warm place. Give all sets the same amount of water, air and light. Observe them daily for a week and record how many seeds germinate and how fast they germinate.