Class 6 Science Chapter 10 Notes Living Creatures: Exploring their Characteristics
→ Movement: Change in the position from one place to another is called movement.
→ Growth: An increase in size, height and girth is referred to as growth. Growth is characteristic of all living things.
→ Nutrition: Nutrition is the process by which food is obtained by the organism to provide energy for the body.
→ Breathing: This is the process in which oxygen- rich air is inhaled and carbon dioxide-rich air is released out. Breathing is part of a process called respiration.
→ Excretion: The process of removal of waste substances from the body of a living being is called excretion.
→ Stimulus: Any thing or any event that prompts living beings to respond is called a stimulus.
→ Reproduction: Reproduction is the process by which living things produce more of their own kind. It is true for both animals and plants. It takes place in many different ways, for different organisms.
→ Some animals produce their young ones through eggs. Some animals give birth to the young ones.
→ Plants also reproduce. Many plants produce seeds which can germinate and grow into new plants.
→ Living Things: Objects which show some characteristics such as need of food, respiration, response to stimuli, movement, growth, and reproduction are called living things.
→ Non-living Things: Non-living things do not have life in them. They do not respire, reproduce, excrete and respond to stimuli.
→ Dead: When a living being is not able to exhibit any characteristics of living beings, despite the availability of all resources (like food, air and water) needed for being alive, it is said to be dead.
→ Essential Conditions for Germination: Germination of seeds depends upon the availability of water, air and suitable light and/or dark conditions. During germination of seeds, roots generally grow downwards, while shoots grow upwards.
→ Life Cycle of a Plant: A plant’s life cycle starts with seed germination, followed by several stages of its growth and development. These include flowering and seed production. Seeds produced during their life cycle would germinate into new plants and the cycle continues.
→ Life Cycle of Mosquito: Mosquitoes pass through four stages in their life cycle—egg, larva, pupa and adult. A mosquito begins its life as an egg, the egg develops into a larva, the larva grows into pupa, and the pupa transforms into an adult mosquito. The adult female mosquito lays eggs directly on or near water, and the cycle continues.
→ Life Cycle of Frog: There are four stages in the life cycle of a frog—the egg stage, the tadpole stage, the froglet stage, and the adult frog stage.
→ Breaking : It is a kind of ventilation in which the organisms take oxygen from the environment and release carbon dioxide.
→ Movement : To go from place to place.
→ Conclude : Come or bring to an end.
→ Death : Dying
→ Non-living : Having no life.
→ Create : Produce.
→ Excretion : It is a biological process by which an organism gets rid of excess or toxic waste products of metabolism.
→ Nutrition : It is the process of intake of nutrient and its utilisation by an organism in various biological activities.
→ Design : Drawing
→ Froglet : Larva.
→ Pupa : The caterpillars enters in the next stage of its life history called Pupa.
→ Experiment : Knowledge or skill acquired from seeing and doing things.
→ Germination: Start growing.
→ Reproduction : Production of new generation of individuals of the same species that are physically independent of their parents.
→ Explore : Travel through in order to learn about it.
→ Growth : Increase in size or quantity.
→ Respiration : It is a process that involves breakdown of nutrients through oxidation and release of energy for cellular needs.
→ Identify : To recognize.
→ Larva : Larva is an immature form of an animal (like frog or silk moth) formed by the hatching of its eggs.
→ Response : Give a verbal or written answer.
→ Observation : To see or notice.
→ Life Cycle : The whole cyclic order of life is known as life cycle.
→ Stimulus : That increases physical or mental activity and alertness.
→ Prediction : Forecast
→ Living : Having life.
→ Tadpole : It is a stage in life cycle of a frog consisting of an early stage with a tail but no legs.
→ The objects around us can be categorised into two types living and non-living.
→ The essential features of living beings are that they move, eat, grow, breath, excrete, response to stimuli reproduce and die. Absence of any of these pictures indicates that they are not living beings.
→ Each living beings goes through several stages during its life.
→ Germination of seeds depend upon the availability of water, air, and suitable light / or dark conditions.
→ During germination of seeds, roots generally grow downwards while shoots grow upwards.
→ A plant’s life cycle start with seed germination, followed by several stages of the growth and development. These include flowering and seed production. Seeds produced during their life cycle would germinate into new plants and the cycle continues.
→ The production of new individuals from their parents is known as reproduction.
→ Most plants have roots, stems and leaves. These are called the vegetative parts of the plant. The flowers perform the function of reproduction in plants. So, flowers are the reproduction organs of a plant.
→ The life cycle of an animal as a result of reproduction, begin with a new born that undergoes various stages of growth and development followed by an adult. Stage and finally death. The process of reproduction maintains the continuity of the kind.
→ Mosquitoes pass through the stages of egg larva, pupa and adult. The life stages of a frog include eggs, ladpoles, froglets and adults.
→ In some living beings, such as mosquitoes and frogs, significant changes occur during the various stages of their life cycles. These hanges can be seen in body shape, structure and sometimes even in the habitat.
Introduction
Living organisms can be seen in various regions of the world – such as plains, mountains, deserts, grasslands, etc. The organisms have unique features that enable them to live in a particular region with specific climate and geographical features. Animals have different kinds of body coverings, varied eating habits, different breathing methods and different body parts for moving.
What Sets The Living Apart From The Non-Living?
All living beings show movement. They respire, reproduce, excrete, respond to stimuli and eventually die. Followings are the features of living things:
→ Movement is a primary characteristic, but it varies among organisms; for instance, animals move freely, while plants show movement in specific parts like flowers opening.
→ Growth is another essential trait, as seen in the way children outgrow their clothes or plants grow larger.
→ Nutrition is crucial for growth and development, with living beings requiring food to sustain life processes.
→ Breathing is the process when we inhale, the air moves from outside to inside our body. When we breathe out, the air moves from inside our body to outside.
→ Respiration is highlighted as a vital process involving the intake of oxygen and release of carbon dioxide, occurring in both plants and animals.
→ Excretion is another fundamental process, where waste products are removed from the body. For instance, humans excrete sweat and urine, while plants excrete excess water and minerals. Stimulus : Any thing or any event that prompts living beings to respond is called a stimulus.
→ Reproduction is the process of producing new ones of one’s own kind.
Absence of any of these above features indicates that they are non-living things.
When a living being is not able to exhibit all of the above mentioned characteristics, despite the availability of all resources (like food, air and water) needed for being alive, it is said to be dead.
Essential Conditions For Germination Of A Seed
→ Germination of seeds depends upon the availability of water, air and suitable light or dark conditions. During germination of seeds, roots generally grow downwards, while shoots grow upwards.
How these conditions help in seed germination?
→ Water : Seeds require water for germination. Water, enables the seeds to carry out the processes necessary for their growth. The outer covering of the seed is called seed coat. Water softens the seed coat and helps the tiny embryo inside it to develop into a plant.
→ Air and Soil : Seeds needs air for germination. They use the air available in the spaces between soil particles. Spaces between the soil particles allow roots to grow easily.
→ Light and/or dark conditions : In general, most seeds do not require light for germination. But after germination, sunlight is required for further growth of the seedling. Some seeds of flowering plants, like coleus and petunia, require light tó germinate. Covering these seeds with soil inhibits their sprouting. Seeds of flowering plants, like Calendula and Zinnia, need darkness to germinate. These seeds should be covered with sufficient soil.
Plants need favourable conditions and nutrients for their proper growth and development. Plants need food to stay alive. The plants make their own food by the process of photosynthesis.
Jagdish Chandra Bose (1858-1937), a scientist
Jagdish Chandra Bose was an Indian scientist. He did some fascinating experiments with plants. He built a machine called Crescograph to record how plants respond to stimuli like light, heat, electricity and gravity with this machine, he could measure how fast plants grow. He also showed that plants can sense and response to stimuli. The leaves of the plant, ‘Touch-me not’ droop on touching them. The tip of the shoot moves towards light. The movement of the shoot towards light is called phototropism. Phototropism is the response of plants towards light, which acts as a stimulus.
Life Cycle Of Animals
All the living things start their life when they are born or hatched from eggs. These living things grow into adults, remain alive for a certain time and finally die.
→ Life Cycle of a Mosquito : Mosquitoes pass through four stages in their life cycle – egg, larva, pupa and adult.
Some common places where stagnant water is likely to gather are desert coolers, planted pots and any open container. You may find two different types of worm-like creatures (Fig. 5). They are larva and pupa, two distinct life stages during the development of mosquito.
→ Significance: Changes occur in the appearance, body shape and structure during the various stages in the life cycle of a mosquito. The shape of the egg is quite different from the larva. The larva appears very different from the pupa. The pupa appears very distinct from the adult mosquito. A mosquito emerges from a pupa.
→ Life cycle of Silk Moth : There are four stages in the life-cycle of a silk moth-egg, caterpiller (larva), pupa and adult. Eggs hatch into larvae, which then grow in size. Larva secrete thread like material which they wrap around themselves, before changing to pupae. These are its fibres that are used to make silk fabric.