Biology

How To Manage Non Biodegradable Waste

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Management Of Non-Biodegradable Wastes

As Non biodegradable wastes like plastic bags, glass bottles, etc., cannot be broken down by decomposers, their disposal poses a big problem. Non-biodegradable wastes can be managed by practicing the concept of 3Rs—Reduce, Reuse, and Recycle.

Reduce

We need to reduce the amount of waste generated by consuming more and throwing away less. We often buy more things than we really need. Nowadays, disposable items have become popular, for example, ballpoint pen, plastic bag, disposable napkins etc. We are using them frequently without giving a thought to their hazardous effects.
Here are some tips for reducing wastes:

  • Use fountain pen in place of a ballpoint pen,
  • Use old newspapers for packaging, and
  • Use cloth napkins in place of disposable ones.

Reuse

We can reuse certain things for more than one purpose. If we reuse them for other purposes, we can help in reducing the waste. Here are some of the tips for reusing things:

  • Small jars and bottles can be cleaned to keep some other kitchen stuffs.
  • One should prefer glass bottle to metal can when buying juice or soft drink. The bottles can be refilled.
  • Old clothes can be made into other usable items like cushion cover, handkerchief, etc.
  • Old mobile phones can be donated to friends or family.

Recycle

The process by which waste materials are used to make new products is called recycling. Materials like glass, metal, plastic, and paper are collected, separated, and recycled to make new things.

Recycling of Plastics

Bucket, bottle, toy, shoe, bag, pen, and comb are a few things made of plastic. Use of plastics has become a major concern nowadays because they are non-biodegradable and release harmful gases upon heating or burning. They can also contaminate foodstuffs. If eaten by animals, plastics can choke and kill them. Therefore, one should reduce and reuse plastic items as far as possible. When plastic items are to be discarded, they should be recycled to make new things.
Not all the plastics generated are recycled, hence causing much damage to life on Earth. In many places in India, plastics are totally banned seeing its adverse effects on the environment.
Some of the ways to reduce, reuse, and recycle plastics are as follows:

  • Paper, cotton, and jute bag should be preferred over plastic bags.
  • Some disposable plastic containers and jars can be used to grow plants.
  • Empty bottles can be refilled for storage of water or any other liquid stuff. Think about the number of times you buy a bottle of water when you are out. Instead you can fill the used bottle and carry it whenever you are out.
  • Zip foils can be reused after cleaning thoroughly each time after storing foodstuffs.

How To Manage Non Biodegradable Waste 1

Recycling of paper

Paper is made from trees and trees are essential for our survival on Earth. So, even if paper is biodegradable, depletion of trees at a fast pace is a big concern. Therefore, to save trees we must use paper carefully. Some of the ways to save paper are:

  • We should always write on both sides of paper sheets.
  • Unused pages from old notebooks can be torn off and made into a new notebook for doing rough work and other miscellaneous work.
  • We can also reuse envelopes and covers by using stickers to write new addresses.
  • We can also make fresh paper from old newspapers.

By now, we know how harmful garbage accumulation can be. But, by following the 3Rs concept, we can manage the garbage generated in our surroundings so that it is beneficial to the environment.

 

Why is it important for Plants to Disperse their Seeds

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Why is it important for Plants to Disperse their Seeds

Seed dispersal
The seed, enclosed in the fruit, needs to separate from its parent plant before it can develop into a new plant. Fruits are adapted in different ways to help in dispersal. But very often, both fruits and seeds together form the dispersal unit. Dispersal takes place by several mechanisms, including wind, water, and a variety of animals.

  1. In the simplest way, seeds are automatically set free by opening of the fruit. An explosive mechanism bursts the fruit open to release the seeds. For example, pea plants, castor, and balsam.
  2. Some seeds have radiating threads or wings that form a parachute so that they can be carried long distances by even the gentlest breeze. For example, Dandelion seeds, drumstick, and maple.

    Why is it important for Plants to Disperse their Seeds 1
    Radiating threads of dandelion seeds
  3. Some seeds have a spongy outer coat to help them float on water. They are carried great distances by ocean currents and germinate after they wash up on beaches. For example, coconuts.

    Why is it important for Plants to Disperse their Seeds 2
    Spongy outer coat of coconut seed

Many types of animals play a role in the dispersal of fruits and seeds.

  1. Most fleshy and brightly coloured fruits are designed to be eaten by birds and mammals. These fruits appear tasty and are highly nutritious for these animals, giving them a reason to forage for the fruits repeatedly.
  2. Some birds eat fruits whose seeds stick to their beaks and then are rubbed off somewhere else. Seeds of other fruits pass intact through a bird’s digestive tract.
  3. Some fruits are covered with little hooks or sticky substances and get caught in the fur or hide of animals such as sheep. As the animal moves about, fruits or seeds are rubbed off by branches of shrubs or trees.

    Why is it important for Plants to Disperse their Seeds 3
    Seedpod with hooks
  4. Ducks may disperse fruits sticking in the mud on their feet.

What are Food chains and Explain their Characteristics

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What are Food chains and Explain their Characteristics

Food chain is a sequence of organisms in a biotic community through which food passes with members of a step becoming food of the members of the next step of the sequence. In other words, it is a list of who eats whom in a biotic community. A food chain usually consists of producers, various levels of consumers and decomposers. Each step or division in food chain which is characterized by a particular method of obtaining food is called trophic level.

Producers :
They constitute the base or beginning of a food chain. They constitute the first trophic level (T1) of a food chain.

Herbivores or first order consumers (Primary consumers) :
They are animals which feed on plants or plant products. e.g., Grasshopper, Rabbit, Deer Elephant. Herbivores constitute second trophic level (T2).

First order (Primary) carnivores or second order consumers (secondary consumers) :
They are animals which prey upon herbivores, e.g., Frog, Wild Cat, Fox. These animals form the third trophic level (T3).

Characteristics of Food chain:

  1. Producers based :
    All sustainable food chains are producer based.
  2. Energy :
    Producers obtain energy from sun. All others (consumers) obtain the energy from food originally built up producers. There is unidirectional flow of energy.
  3. Biogenetic Nutrients :
    Inorganic nutrients must keep on circulating with the help of decomposers. Otherwise, food chains cannot be sustained.
  4. Straight :
    Unless linked with another, food chain runs straight.
  5. Size :
    Food chains are generally short with 3-5 trophic levels.
  6. Populations :
    Size of populations decreases with the rise in trophic level. Top carnivores are always very few.
  7. Operation at different trophic levels :
    An organism can operate at more than one trophic level, e.g., snake feeds on herbivorous rat as well as carnivorous frog.

Types Of Blood Vessels In Human Body

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Types Of Blood Vessels In Human Body

There are three types of blood vessels present in human circulatory system.
(A) Arteries:
• Arteries carry blood from heart and supply to organs. These are thick muscular walled and deep seated. All Arteries carry oxygenated blood except pulmonary arteries which carry deoxygenated blood to lungs for purification. They do not have valves.
(B) Veins:
• Veins collect blood from the tissue of the organs and Bring it to the heart through two big veins, the superior and Inferior vena cava. Veins carry deoxygenated blood except pulmonary veins. Veins are thin walled and placed more superficially. They contain valves.
(C) Capillaries:
Capillaries are extremely thin-walled and narrow. They are closely placed with the cells of the tissue in an organ. Oxygen and food pass into the cells and carbon-dioxide and other wastes pass into the capillaries from the cells.
Important Terms:
The following terms should be clearly understood before studying blood group.
(A) Antigen:
• A substance capable of stimulating the formation of an antibody is called antigen.
• It is any substance, a bacteria or virus, that the body regards as foreign and it may be formed in or introduced into the body, it is capable of causing some disease in the body and are present in the red blood cells of the donor.
(B) Antibody:
• It is specialised protein produced by certain white blood cells (lymphocytes) in response to entry into the body of a foreign substance. i.e. antigen in order to render it harmless.

Transportation In Human Beings

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Transportation In Human Beings

In humans, transportation of oxygen nutrients, hormone and other substances to tissue, CO2 to the lungs and waste products to the kidneys is carried out by a well-defined Circulatory System. In lower organisms material is transported by diffusion.
Circulatory System:
It comprises of the heart, blood vessels, blood, lymphatic vessels, lymph, which together serve to transport materials, throughout the body.
Components of the circulatory system in higher animals are –

  1. Blood
  2. Pumping organ- ‘Heart’
  3. System of blood vessels for distribution and collection of blood – consisting of arteries, veins and capillaries.

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1. Blood Corpuscles:

  1. Red Blood Corpuscles (RBC) or Erythrocytes :
    These are minute, circular biconcave discs having no nucleus. They look red due to the presence of red coloured pigment, haemoglobin. Red blood cells have life span about 120 days. They are produced in bone marrow number is 4.5 – 5.5 millon/cu.mm.
    Function:
    Haemoglobin transports oxygen from lungs to body tissues.
  2.  WBC or White Blood Cells or Corpuscles:
    These are large, nucleated colourless cells and are less numerous than erythrocytes. There are about 5000 W.B.C per mili litre of blood. They move actively and protect the body against disease-causing microorganisms by destroying them.
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    WBC are mainly of two Type W.B.C.
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  3. Blood Platelets:
    Platelets are rounded, colourless, biconvex and non-nucleated blood- cells, which help in the coagulation of blood they are called thrombocytes. Whenever you have a cut on your body, blood comes out. The bleeding is stopped after sometime by the blood platelets present in the blood. Blood platelets are colourless, irregularly shaped, and much smaller than the RBCs.

2. Blood Vessels
Blood flows through our body in a complex system of tubes called blood vessels. There are three types of blood vessels: arteries, capillaries, and veins. Capillaries are the thinnest of the blood vessels and connect arteries to veins. Differences between arteries and veins are listed Table.
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Capillaries are thin-walled blood vessels and form a network of extremely tiny blood vessels between arteries and veins. The walls of the capillaries are so thin that diffusion of gases and chemical substances takes place very easily.
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3. The Heart
The heart is a four-chambered muscular organ that pumps blood into the blood vessels. The pressure that this pumping generates is enough for the blood vessels to carry this blood to all parts of the body. The heart is able to do so by the rhythmic contractions and relaxations of its muscles. These are known as the heart beats. A normal heart beats about 60 to 80 times per minute. We can hear our heart beat with the help of an instrument called a stethoscope.
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As the heart beats and forces blood through our body, we would feel a throbbing sensation at any point where an artery comes close to the surface of your skin, such as the wrist, neck, or upper arm. This throbbing sensation is called the pulse. Counting your pulse rate is a simple way to estimate how fast your heart is beating.
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The four chambers of the heart are (i) the right auricle (ii) the left auricle, (iii) the right ventricle, and (iv) the left ventricle. The right auricle opens into the right ventricle and the left auricle into the left ventricle.

Activity
Aim: To measure your pulse
Method:
1. Feel your pulse by placing the index and middle finger over the underside of the opposite wrist, below the base of the thumb.
2. Do not use your thumb because it has its own pulse that you may feel.
3. Count the beats for 30 seconds, then double the result to get the number of beats per minute.