Chapter 10: Living Creatures: Exploring Their Characteristics
Chapter 10
Living Creatures: Exploring Their Characteristics
1. Living and Non-living Things
Things around us can be classified as living and non-living.
Living beings show certain common characteristics:
- Movement
- Nutrition (need food)
- Growth
- Respiration
- Excretion
- Response to stimuli
- Reproduction
- Death
A car can move, but movement alone does not make something living. Plants also show movement even though they do not move from one place to another. For example, flowers open and insectivorous plants such as Drosera show movement.
2. Characteristics of Living Beings
A. Movement
Living beings show movement. Animals can move from one place to another.
Plants also show movement:
- Flowers open.
- Drosera traps insects by movement of its leaves.
- Climbers wind around nearby objects.
Therefore, movement does not always mean moving from one place to another.
B. Growth
Living beings grow and increase in size.
For example, a child becomes larger as they grow. Plants and other living organisms also grow.
Living beings require food/nutrition for growth and development.
C. Respiration
Breathing is a part of the process called respiration.
- During inhalation, air enters the body.
- During exhalation, air moves out.
- All living beings respire.
- Plants have tiny pores called stomata through which air moves in and out.
D. Excretion
The removal of waste products from the body is called excretion.
Examples:
- Humans remove waste through sweat and urine.
- Plants can remove excess water and minerals as droplets from their leaves.
E. Response to Stimuli
A stimulus is anything or any event that causes a living being to respond.
Examples:
- Touching a hot object → we quickly withdraw our hand.
- Stepping on a thorn → we immediately react.
- Touch-me-not (chhui-mui/Mimosa) folds its leaves when touched.
Thus, living beings respond to stimuli.
F. Reproduction
Reproduction is the process of producing new organisms of one's own kind.
It is important for the continuity of life.
G. Death
When a living being can no longer show the characteristics of life, even when necessary resources are available, it is considered dead.
3. Seed Germination
Germination is the process by which a seed develops into a sprout.
A seed requires suitable conditions for germination.
Important conditions
- Water – softens the seed coat and helps the embryo develop.
- Air – seeds need air for the processes necessary for germination.
- Suitable conditions of light/darkness – bean seeds generally do not require light for germination, although sunlight is required for further growth after germination.
Most importantly, seeds need the right amount of water and air.
Seed Structure
A seed has:
- Seed coat – outer covering
- Embryo – tiny developing plant inside the seed
4. Growth and Movement in Plants
Plants respond to sunlight.
When a plant is kept upright:
- Root grows downwards.
- Shoot grows upwards.
When a plant is inverted:
- The root bends and grows downwards.
- The shoot bends and grows upwards.
When sunlight comes from only one direction:
- The shoot grows towards the light.
- The root continues to grow downwards.
Jagadish Chandra Bose
Jagadish Chandra Bose (1858–1937) was an Indian scientist who studied how plants respond to stimuli such as light, heat, electricity and gravity. He developed a machine called a crescograph to record plant growth.
5. Life Cycle of a Plant
The complete series of changes a plant undergoes from one generation to the next is called its life cycle.
Life cycle of a bean plant
Seed → Germination → Young plant/Leaves → Flowers → Fruit/Pod with seeds → New generation
A seed grows into a young plant. The plant matures, produces flowers and fruits, and the fruits contain seeds. These seeds can grow into new plants.
6. Life Cycle of a Mosquito
Mosquitoes commonly breed in stagnant water.
Four stages:
Egg → Larva → Pupa → Adult mosquito
- Egg: First stage.
- Larva: Develops from the egg.
- Pupa: Develops from the larva.
- Adult: Emerges from the pupa.
The adult female mosquito lays eggs on or near water, and the cycle continues.
Why do mosquito larvae and pupae come to the water surface?
They live in water but need air for respiration, so they repeatedly come to the surface.
7. Life Cycle of a Frog
A frog undergoes several stages during its life.
Main stages:
Spawn/Eggs → Embryo → Tadpole → Tadpole with legs → Froglet → Adult frog
- Tadpole has a tail and lives in water.
- Later, legs develop.
- The tadpole becomes a froglet.
- The tail gradually disappears.
- The froglet develops into an adult frog.
Importance of the tadpole's tail
The tail helps the tadpole swim in water.
8. Life Cycle of Animals
Animals also pass through different stages during their lives.
A general life cycle includes:
Birth → Growth and development → Adult → Reproduction → Death
Reproduction ensures the continuity of the kind.
Important Differences
| Living Beings | Non-living Things |
|---|---|
| Need nutrition | Do not need food |
| Grow | Do not grow naturally |
| Respire | Do not respire |
| Excrete | Do not excrete |
| Respond to stimuli | Do not respond biologically |
| Reproduce | Do not reproduce |
| Eventually die | Do not undergo biological death |
NCERT Exercise – Questions and Answers
Q1. List the similarities and differences in life cycles of plants and animals.
Answer:
Similarities:
Both plants and animals pass through different stages during their life.
Both begin life from a new individual and grow into adults.
Both undergo growth and development.
Both reproduce to continue their kind.
Both eventually die.
Differences:
| Plants | Animals |
|---|---|
| Plants generally begin their life cycle from seeds. | Animals may be born from eggs or directly from the mother. |
| Plants grow into seedlings, mature plants, and produce flowers and fruits. | Animals pass through stages such as young ones and adults; some undergo distinct stages such as larva and pupa. |
| Plants can produce new seeds after flowering and fruit formation. | Animals reproduce by giving birth or laying eggs. |
| Plant life cycles commonly include germination, growth, flowering and seed production. | Animal life cycles may include stages such as egg, larva, pupa, tadpole, froglet and adult. |
Q2. The table shows some data. Study the data and try to find out examples appropriate for the conditions given.
Answer:
Examples can be identified by considering the characteristics of living organisms such as growth and respiration.
An organism that grows and respires is a living organism.
A living organism may show different rates of growth and respiration depending on its age and conditions.
Young and growing organisms generally show noticeable growth.
Respiration occurs in living organisms even when growth is not easily observed.
Conclusion: Growth and respiration are important characteristics that help us identify living organisms.
Q3. You have learnt that different conditions are required for seed germination. How can we use this knowledge for proper storage of grains and pulses?
Answer:
Seeds require suitable conditions such as water and air for germination. Therefore, grains and pulses should be stored in dry conditions so that they do not absorb moisture.
Keeping grains and pulses dry prevents germination and also helps in their proper storage.
Key point:
Less moisture → no germination → better storage of grains and pulses.
Q4. You have learnt that a tail is present in a tadpole but it disappears as it grows into a frog. What is the advantage of having a tail in the tadpole stage?
Answer:
The tadpole lives mainly in water. Its tail helps it in swimming and moving through water.
As the tadpole develops into a frog, it develops legs and gradually changes its way of movement. Therefore, the tail is no longer needed and eventually disappears.
Q5. Charan says that a wooden log is non-living as it cannot move. Charu counters it by saying that it is living because it is made of wood obtained from trees. Give your arguments in favour or against the two statements.
Answer:
Charan's statement is correct in the sense that a wooden log is non-living. It does not grow, respire, reproduce or respond to stimuli like a living plant.
Charu is correct that the wood was obtained from a living tree, but after the tree's wood becomes a wooden log, the log itself is no longer a living organism.
Therefore, a wooden log is non-living, although it has come from a living plant.
Q6. What are the similarities and distinguishing features in the life cycles of a mosquito and a frog?
Answer:
Similarities:
Both begin their life cycle from eggs.
Both undergo several stages before becoming adults.
Their young stages look different from the adults.
Both undergo significant changes in body form during their life cycle.
Differences:
| Mosquito | Frog |
|---|---|
| Egg → Larva → Pupa → Adult | Egg/spawn → Embryo → Tadpole → Froglet → Adult |
| The mosquito has a distinct pupa stage. | The frog does not have a pupa stage. |
| The larva and pupa are aquatic stages. | The tadpole is mainly aquatic. |
| Adult mosquito is different in form from the larva and pupa. | Adult frog develops legs and changes from the tadpole form. |
Q7. A plant is provided with all the conditions suitable for its growth. Draw what you expect to see in the shoot and the root of the plant after one week. Write down the reasons.
Answer:
After one week:
The root will grow downward into the soil.
The shoot will grow upward away from the soil.
The shoot will develop leaves as it grows.
Reason:
Roots generally grow downward, while shoots generally grow upward. The experiment in the chapter shows that even when the seedling is placed differently, the root bends downward and the shoot grows upward.
Expected observation:
Shoot ↑
🌱
Root ↓
Q8. Tara and Vijay set up the experiment shown in the picture (Fig. 10.10). What do you think they want to find out? How will they know if they are correct?
Answer:
They want to find out how a plant's shoot and root respond to light and direction.
They can observe the plant over several days and compare the direction in which the shoot and root grow.
If the shoot bends towards the light while the root grows downward, their prediction will be supported.
Observation:
Shoot → grows towards the light.
Root → grows downward.
Q9. Design an experiment to check if temperature has an effect on seed germination.
Answer:
Aim:
To find out whether temperature affects seed germination.
Materials required:
Two or more containers, equal numbers of similar seeds, cotton/soil and water.
Procedure:
Take two containers and place the same number of similar seeds in each.
Provide both containers with the same amount of water and air.
Keep one container in a suitable warm place.
Keep the other container in a much colder place.
Observe the seeds every day for several days.
Record the number of seeds that germinate.
Observation:
Compare the germination of seeds kept at different temperatures.
Conclusion:
If the seeds kept at different temperatures show different rates or amounts of germination, it shows that temperature has an effect on seed germination.
Important: Keep all other conditions, such as seed type, amount of water, air and number of seeds, as similar as possible so that temperature is the main variable.
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