Popular science 50 experiments from the living world

TATJANA MIHAJILOV KRSTEV

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50 EXPERIMENTS FROM THE LIVING WORLD

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Illustrations

Nemanja Ristić

Tatjana Mihajilov Krstev

from Live World

50 GET TO FE KNOW LI ES! S S E C O R P Illustrations

Nemanja Ristić

Tatjana Mihajilov-Krstev

from The Living World

O

ur biology classes could have been quite ordinary: they would have lasted for 45 minutes, sometimes we would have listened to the teacher, or done revisions, and sometimes we would have even done a bit of daydreaming… But our classes are nothing like that. And it is all thanks to our teacher. She loves nature very much. As soon as she mentions it, she starts humming.

Class, oh, class… la-la-la… we have a wonderful assignment today! We’re going outdoors to see if the sleeping buds on that pruned ash tree has awakened!

When our biology teacher says outdoors, she means our schoolyard. She sees nature in everything. Truth be told, we like going with her and checking all sorts of organisms that surround us. And we always have a good time!

Let us go exploring together! Do you want to get to know live world and the laws which govern it, just like scientists do?

If you are asking yourself how you are going to do it, look for the answers in this book. Various experiments about living organisms and life processes are described in it.

You will get to know how interesting and exciting it is to study plants and animals.

INSTRUCTIONS

FOR THE EXPERIMENTS

Before

you begin‌

1. Find out the facts about the experiment you will conduct and read through the description of the work process.

2. Gather all necessary equipment and material for conducting the experiment.

3. Think through whether you need somebody’s help in conducting the experiments.

4. Choose a suitable spot for performing the experiment and check if

the text says you need special conditions (that the experiment should be conducted outdoors, whether you need light, in school lab, etc.).

5. Make sure you have ample time for work.

6. Do not let anyone disturb you while you are working.

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It is a good thing to keep your place for work tidy and protected from dirt and damage.

That is why you should cover it with oilcloth and put the equipment and material over the oilcloth. When it is necessary, use thin gloves and protective glasses for work.

Once

You Get Started‌

1. Be careful to follow the procedure, because it is vital to the outcome of an experiment.

2. Use potentially dangerous instruments (scissors, knife stove) in the presence of an adult.

3. Be careful not to spill anything during work. If you spill

a chemical onto yourself, immediately wash yourself thoroughly with soap and water and inform an adult about it.

4. Keep a lab log in which you can enter your observations or difficulties you encounter while experimenting.

5. Take photographs of the experiments’ phases which you think might be of use later.

6. Tidy up and clean your workspace after an experiment.

Planning an experiment is very important. However, even with a good plan, mistakes can happen.

That is normal. Every explorer makes mistakes sometimes.

If that happens, think carefully, and then repeat the experiment.

Everything will probably go well then.

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A TERRIER AND BASIL HAVE NOTHING IN COMMON Class, oh, class… how can we show that we love nature?

Hmm….la-la-la…! Here, for example, we can adopt a living creature and take care of it.

Look how versatile nature is!

Everyone can find something appropriate.

Place where new leaves are created

Tender leaves with beautiful smell

Moist soil

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I adopted a plant. It is known as the basil. It has tender leaves which smell wonderful.

It is also used as spice, but I would hate to rip its leaves. I water it three times a week. The plant is growing and getting new leaves. When it grows a little bit bigger, the buds and tiny flowers will appear.

I love my plant! I don’t like aphids nor the dog that wants to throw the soil out of the plant pot.

I adopted a dog. He belongs to the Norfolk terrier species. He has rough hair, dark eyes and beautiful small paws. His sense of smell is terrific and he always knows when I open a box of food. He eats twice a day. His ears are small and folded. He likes chasing squirrels, but never catches up with them.

He is happy when he sees me.

I love my dog. I don’t want anyone to scold him when he runs around the garden and tramples on flowers which aren’t fun anyway.

Tail Bristle hair Small folded ears Dark eyes

Snout

Small paws

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MAYBE THEY HAVE SOMETHING IN COMMON AFTER ALL THE LIST OF LIFE PROCESSES • Birth (a live being comes into existence by division; it is hatched from an egg; it is born alive) • Growth, development • Breathing (a live being takes oxygen in, and lets carbon-dioxide out) • A live being feeds (produces food, hunts, grazes, suckles, picks food) • Discharge of unnecessary matter (a live being sweats, secretes sap, discharges products of digestion, emits gas) • A live being moves (walks, crawls, leans, bends, flies) • Reactions to environmental conditions (a live being heats, cools, reacts to light, sound, touch) • A living being reproduces (asexually or sexually) • Aging and dying.

The dog and the plant really differ, but they also have plenty of similarities. Live beings are similar in that respect that they can perform life processes. In fact, they must perform them. Let us check this with the help of this list.

1. PROOFS OF LIFE In live world, nothing WHAT YOU NEED TO DO happens accidentally and 1. Read the list and find out all life processes. everything is subjected 2. In given descriptions find the characteristics which fall into the to the sustenance of life. category of life processes.

Check if characteristics of 3. Write numbers of the found life processes on the line under living beings have anything the picture. (When you finish the assignment, check the page to do with life processes XXXX for the correct answer.) which take place in them.

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GINKGO is a gymnosperm tree that dates from the times of dinosaurs. That is why it is rightfully called a living fossil. It grows to the height of 40m, and can live up to be 1000 years old. It feeds on the matter it produces. Its leaves are fan-shaped with cuts that go through the middle, with visible venation through which liquid circulates. It used to grow only in China, and today it is a favorite park species because it handles pollution well and purifies city air.

TRYPANOSOMA is a protozoan (a one-cell microorganism) from Africa and South America. It moves using flagella. It absorbs dissolved organic food and oxygen from the environment with the body surface. It discharges carbon-dioxide and other waste matter in the same way. It is a parasite which spends a part of its life in the bowels of the tsetse fly, where it reproduces and gets into salivary glands.

When the fly bites a man or a domestic animal, it infects them and causes the sleeping disease.

PLATYPUS is a primitive mammal that lives in Australia, New Guinea and Tasmania. It swims in freshwater and digs burrows on riverbanks.

Its body is covered in hair and it looks like a mole; its snout is flat and ends in a bill that looks like a duck’s; the tail is thick like in a beaver.

At the end of the bowel there is the cloaca, into which excretion and reproductive organs pour. The young are hatched from eggs, and then suckle until they are fully grown. The platypus feeds on invertebrates, fish and tadpoles.

MIMOSA PUDICA (SHY PLANT) is an annual herbaceous plant native to America. The shy plant bush grows up to 70 cm, has prickly stem and pink flowers. It is sensitive to temperature changes and usually cannot survive winter. In spring, however, it is easily grown from the seed. It got its name due to the characteristic of its leaves to close quickly as a reaction to touch, and return to the initial position in several minutes. It is cultivated throughout the world as a decorative plant.

HERMANN’S TORTOISE is a reptile that has a characteristic shell of brown-green color with dark spots. It grows to 20 – 25 cm in length.

It moves slowly on four short stocky legs. It feeds mostly on plants. It breathes with lungs. It reproduces by mating, after which the female lays eggs. The young hatch two or three months later. The Hermann’s tortoise is an endangered species because it is hunted for its meat, but also the shell which people use to make decorative objects.

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HERMANN’S TORTOISE is a REPTILE that has a characteristic shell of brown-green color with dark spots. It grows to 20 – 25 cm in length. It moves slowly on four short stocky legs. It feeds mostly on plants. It breathes with lungs. It reproduces by mating, after which the female lays eggs. The young hatch two or three months later. The Hermann’s tortoise is an endangered species because it is hunted for its meat, but also the shell which people use to make decorative objects.

BASIL is a perennial herbaceous plant originating from India. Its shoots can grow up to 80 cm and are covered with hair. The flowers are small, grouped in inflorescences. The plant secretes essential oils and is used in medicine and cooking. It reproduces by the seed. The root of basil is well developed and absorbs plenty of water, which is why it needs to be watered regularly.

FLY AGARIC is a mushroom that inhabits forests and sunny glades of Europe, America and Africa. Its body (mycelia) consists of pipe-like structures (hyphae). It grows underground and branches by feeding on dead organisms. Fruit-bearing bodies (mushrooms) appear on the ground surface as a result of sexual reproduction. They have a great number of spores, out of which new mushrooms will develop. Their hats are red with white spots and they are highly poisonous.

TERMITES are social insects that live in nests made in trees or soil in tropical or subtropical areas. They eat plants, most often dead trees. Three castes make a colony: a queen and a king reproduce; workers make a nest, clean it from waste matter and take care of larvae; soldiers defend the society from enemies. Sexually mature termites get two pair of wings, which they bite off after swarming and reproduction.

A DOG is a mammal. It originates most probably from the wolf. Today there are about 800 breeds of dog. Its senses are extremely well developed, and its sense of smell and hearing are far better than man’s.

It feeds on meat, but it can also eat milk, eggs, vegetables, fruit and cereals. When it is hot, it cools itself by panting, and through the paw pads, because that is where most of the sweat glands are. For many thousands of years, dog has lived side by side with man as pet, guard, guide, rescuer and hunter.

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HUMMINGBIRD is the smallest bird in the world. Some species do not exceed the size of a bumblebee. Its feathers are of various colors, with a metallic reflection. Its beak is elongated and it can be inserted in a flower while it is being fed on the nectar. Its tongue is long, split at the tip and has a shape of a straw. The hummingbird flaps its wings even 80 times in a second and can flies sideways, in reverse and can float in one place. Its heart has up to 500 beats, and inhales up to 250 times in a minute. The female of a hummingbird lays only two eggs.

It lives in North and South America.

SALMONELLA is a stick-like bacterium that lives in rivers, waste waters and soil. It moves using whip-like tails. It feeds on organic food, during which it discharges waste matter. The best environment for its reproduction and development is food, and its presence can cause contamination of food (especially eggs and meat). In animals or people who consume such food, salmonella causes gastrointestinal disease salmonellosis.

What can The beings described here have many similarities. Each of them has three or more characteristics from the you notice? list. A dog and a plant perform similar life processes.

Why?

All living beings are born, they grow and develop, breathe, feed, discharge the products of metabolism, react to environmental conditions, breed, age and die. That means that all living beings perform life processes and are similar to one another in that respect.

Carl von Linne (1707-1778) was a Swedish botanist who is considered the founder of the modern taxonomy – a branch of biology which classifies all organisms. He introduced marking and naming of every living being with two names: the first is a generic name and the second is a specific epithet. So the scientific name of basil is Ocimum basillicum.

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2. FIVE KINGDOMS Scientists have grouped living beings in various ways, always according to some similarities.

One of those ways is grouping them in five kingdoms.

WHAT YOU NEED TO DO

1. See what kind of organisms belong to each kingdom.

2. Enter the names of the beings from the description in the corresponding kingdom. Then, check on the page XXX if they are in the right place.

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MONERA Bacteria and archaea (organisms that live in extreme environmental conditions)

PROTISTI Alagae, protozoans (amoebae, flagellates, ciliates and sporeforming protozoans) and fungus-like organisms (water molds and slime molds)

FUNGI Yeasts (one-cell) and mushrooms (multi-cell) organisms

PLANTAE Horsetail, moss, fern, gymnosperms and angiosperms (flowering plants)

ANIMALIA Invertebrates (sponges, coelenterates, worms, arthropods, mollusks and echinoderms) and vertebrates (fish, amphibians, reptiles, birds and mammals)

Monera: Salmonella; Protisti: Trypanosoma; Fungi: Fly agaric; Plantae: Basil, Ginkgo, Shy plant; Animalia: Dog, Fire salamander, Hermann’s tortoise, Termites, Hummingbird, Platypus.

Solution

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3. EXPLORE THE STRUCTURE OF A CELL Living beings are made of cells. Some beings have only one cell, whereas others have many. Life processes take place in cells: they breathe, feed, reproduce, grow. What makes these processes possible is cell organelles – spaces in cytoplasm separated by membranes that have specific structure and function.

WHAT YOU NEED TO DO

1. Read the descriptions of cell organelles. Then, while observing the details of a plant and animal cell, mark every description by a corresponding number.

CELL MEMBRANE A thin membrane that encases the cell’s cytoplasm. It is a semipermeable barrier that decides what goes in and what goes out the cell. All cells have a membrane.

RIBOSOMES are little dots that are everywhere in the cytoplasm, but also on the surface of the intracellular network. They participate in creating protein, i.e. connecting separate amino acids into protein.

NUCLEUS is the big ball-shaped organelle.

It is wrapped in two membranes, and it contains hereditary material inside. The organelle controls all the processes in a cell.

CYTOPLASM A thick liquid that fills the whole inside of a cell. All organelles are in it.

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INTRACELLULAR NETWORK (ENDOPLASMIC RETICULUM)A net-like organelle that fills the cytoplasm. It can be smooth or rough (when it has ribosomes on the surface). Inside the network lipids (fats) are produced and proteins created in these ribosomes are packed. After that, bubbles are made, and they carry these products to the Golgi complex.

GOLGI COMPLEX is a system of sacs set next to each other, with enlargements on its ends. Transported proteins and lipids are stored in them. First, they are processed there, and then they are re-packed. Bubbles with ready matter separate from the edges of the sacs and transport it to other parts of the cell or outside of it.

VACUOLE is a big elliptical membrane-bound organelle. It functions as a reservoir for water and other matter. Such vacuoles are found only in plants.

MITOCHONDRION A small kidney-like part encased in two membranes. The inner membrane is wrinkled in order to have as wide a surface as possible. Cell breathing goes on inside of it – the oxygen is wasted and molecules rich in energy are produced. The molecules are fuel for carrying out life processes. Many such organelles are found in the cell and they are present in every part of the cytoplasm.

CHLOROPLAST Elliptical unit found only in plant cells in large quantities. Encased in two membranes, containing structures inside of them (thylakoids and lamellae) containing green pigments. In chloroplast, with the help of sunlight absorbed by the pigments, nutrients (sugar) are produced.

This process is called photosynthesis.

LYSOSOME A spherical organelle encased in a single membrane. Its function is cell digestion – it encases and with its enzymes decomposes nutritious particles, old parts of the cell or any intruders (bacteria).

There are many lysosomes in one cell.

CELL WALL is on the surface of a cell and is very firm. It provides protection for the cell and gives it shape. Only plant cells have cell wall.

Viruses are the only living organisms not made of cells.

Matthias Schleiden (1804–1881) was a German botanist. Together with

Theodor Schwann he formed the cell theory which stated that cells are the “elementary particles of organisms” in both plants and animals.

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A MULTITUDE OF BUSY CELLS

Cells are what plants and animals are made of. Wonderful plants and animals! La-lalaaaa... But an organism is more than just a bunch of any old cells. Groups of cells of the same shape, structure and function make tissues that make organs – parts of which an organism is made. That is why the first thing we are going to do is see what kind of tissues are there.

PLANTS GROW THROUGHOUT WHOLE LIFE There are places in plants’ bodies in which there are cells that divide incessantly. These are meristem cells. Thanks to them, plants’ length and thickness grow constantly.

Cells specialized in performing specific functions usually do not have the ability to divide. They make vascular bundles. Let us take a look at the functions these tissues have.

• Epidermis is on the surface; it protects the plant and provides its connection with the environment outside the plant.

• Vascular tissue conducts water and nutrients and is important for food production and storage.

• Supporting tissue maintains the shape and firmness of the plant.

• Glandular tissue secretes various products.

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ANIMALS GROW WHILE THEY ARE YOUNG In the early period of the animal organism cells divide and get specific functions. Groups of cells, just like it is the case with plants, make tissues.

When the growth and development of the animal organism is over, new cells are produced only as a substitute for the damaged or aged ones.

Study the function of tissues in the animal body.

• Epithelial tissue has protective, and sometimes glandular or sensory role. It is made of compacted plate-like skin and mucous membrane cells, sometimes with cilia and other outgrowths.

• Connective tissue is, in fact, a group of tissues with various functions. It provides support for the body, transports matter, provides the elasticity of blood vessels, nerves and organs, builds ligaments, stores fat reserves.

• Muscle tissue has the ability to contract and stretch, which enables the mobility of the body, widening and narrowing of blood vessels, bowel movements and heart function.

• Nervous tissue enables the organism to react to stimuli from the external environment. It makes the brain, spinal cord and nerves.

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ORGANS AND ORGANISM Different tissues build organs.

Organs that have a common function are mutually connected in organ systems. A sum of all organ systems make an organism.

Let’s check it out!

4. WHICH ORGANS DOES THE BASIL HAVE? Flowering plants are the most complexly built plants.

The basil is one of them.

The organism of a flowering plant has vegetative organs which keep the plant alive, and reproductive organs, whose function is reproduction. Explore the organs of the basil.

WHAT YOU NEED TO DO

1. Read the descriptions of plant organs and compare them to the picture.

2. Enter the names of these organs in empty slots.

3. Answer the questions next to the names of specified organs of the basil.

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A FLOWER is a short offshoot modified due to its function in sexual reproduction. It consists of flower stalk, receptacle, perianth (calyx and corolla) and stamens and pistil. Male reproductive cells are produced in the stamens, and seed ovules start to develop at the bottom of the pistil. Some flowers develop both male and female reproductive cells (bisexual flowers), while others have cells of one sex (unisexual flowers).

A collection of several flowers on one stalk is called a cluster.

THE FRUIT is a modified part of ovary of the pistil. It is formed from the wall of the ovary containing a fertilized seed. It enables the seed to mature and disperse.

The SEED develops from fertilized seed ovules. In it, protected from adverse conditions, the germ of a new plant feeds. After the maturation of the seed, the fruit falls off, and the loose seed germinates into a new plant.

A LEAF is a vegetative plant organ. It consists of a petiole, blade and stipules.

Its function is to absorb light, produce food (in the process of photosynthesis), exchange gases and leak water through the openings on it. Leaves of some plants are modified (some do not have a petiole, some have the shape of a thorn, etc.).

A STEM is a vegetative plant organ. Its main function is to transport water from roots to leaves and sugars from leaves to roots. Some plants have woody stems, and some have fern stems.

A ROOT is a vegetative organ of a plant. Its function is to absorb water and minerals from the soil and to fasten the plant to the ground. A root can be spindle-shaped (i.e. with a thick central part that branches off) and hairy (i.e. consisting of many small roots of the same thickness).

Root parts are: root cap, cell division zone, growth zone and absorption zone.

QUESTIONS FOR THE POSITION IN THE PICTURE

1. Is basil’s root spindle-shaped or hairy?

2. What kind of stem does basil have?

3. Does basil’s leaf have a petiole?

4. Is basil flower bisexual or unisexual?

5. Is basil’s flower one or grouped into a cluster?

6. Where in basil is the seed formed?

7. What matures in the fruit?

1. Spindle-shaped; 2. Fern; 3. Yes, it does; 4. Bisexual; 5. It is grouped into a cluster; 6. In the flower; 7. The seed.

Solution

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5. NAME THE ORGANS OF A NORFOLK TERRIER? Animals with the most complex anatomy are mammals, which include the Norfolk terrier. Man is also a mammal. Many animal organs have common functions and are mutually connected in organ systems. Some of them are shown in the picture. The sum of all organ systems make an organism.

WHAT YOU NEED TO DO

1. Read the descriptions of organ systems of animals and compare them to the picture.

2. Enter the names of these organs in the empty slots.

3. Answer the questions next to the name of the specified organs of the terrier.

SKELETAL SYSTEM is a group of bones connected with sutures, cartilage or ligaments. It supports the organism, protects inner organs and plays a part in moving the body.

RESPIRATORY SYSTEM enables the exchange of gases, primarily oxygen and carbon-dioxide, between the organism and external environment. It consists of nasal cavity, pharynx, trachea, bronchi, bronchioles and alveoli.

REPRODUCTIVE SYSTEM produces the cells and matter necessary for the creation of new living beings and the survival of a species. It consists of sex glands in which male and female reproductive cells are produced, excretory ducts of the glands and reproductive organs. An embryo of a mammal, which include both dog and man, develops in the uterus until it is mature enough. The period in dogs is 62 days, whereas in humans it is 280 days.

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DIGESTIVE SYSTEM is a group of organs that participate in the digestion of food and absorption of digested matter. It consists of oral cavity with teeth and tongue, pharynx, esophagus, stomach, small intestine, colon, and glands (salivary, liver and pancreas).

MUSCULAR SYSTEM is a group of muscles that plays a part in moving the body, heart function and the protection of inner organs, as well as thermoregulation.

CIRCULATORY SYSTEM enables the transport of gases and matter between different organs and every cell in the body. It consists of cardiovascular and lymphatic systems. It transmits the hormones that control the function of internal organs. Apart from that, it participates in the defense of the organism and the control of body temperature.

Nostrils are used for breathing

Muscles of a dog are strong enabling it to walk, run and even jump

Tongue helps in taking food and water.

When a dog is drinking water the tongue bends in a shape of a spoon Dogs do not have the collar-bone so strong muscles connect front legs and torso

In the womb of a female dog the puppies can grow

When you put your hand on the dog’s chest you feel the heartbeat

QUESTIONS FOR THE POSITION IN THE PICTURE OF A NORFOLK TERRIER

1. How many toes does the terrier use to stand?

2. What does it mean when the terrier wags its tail?

3. What function do fangs perform in the terrier?

4. How does the terrier breathe and can it sneeze?

5. Can a terrier have its blood checked and why would that be done?

6. How does a dog cools itself?

7. Are terrier puppies born?

Solution

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1. 16 (4x4). 2. It is happy. 3. For tearing food, just like in humans. 4. It breathes with its lungs. By sneezing, it cleans its airways. 5. Yes, it can, because its blood test results can tell us if it’s healthy or not. 6. By panting. 7. Yes.

TATJANA MIHAJILOV KRSTEV

Otkrij sličnosti između živih bića.

Izvedi eksperimente i ispitaj osobine živih bića.

Potraži mesta na kojima mogu da se sretnu živa bića.

Saznaj koji su naučnici proučavali biljke i životinje.

Upoznaj životne procese!

50 EXPERIMENTS FROM THE LIVING WORLD

Pročitaj zanimljive priče o živim bićima.

50 UPOZNAJ ŽIVOTNE !

PROCESE

Illustrations

Nemanja Ristić

Tatjana Mihajilov Krstev

from Live World