Reptiles

 
Watch the video and answer:

1)      What are the distinctive features of reptiles?

2)      What is the function of the reptile’s scaly skin?  

3)      What’s the difference with amphibians’ skin?

4)      Snakes use their scales to help grip the ………………………………….

5)      In turtles and tortoises, some scales have evolved into armour ……………………………….

6)      Why do crocodiles have long tails?

7)      What does the term “cold-blooded” means?

 

INVERTEBRATE ANIMALS

PRINCIPAL CHARACTERISTICS

Invertebrate animals are alike in one way: they have no inner skeleton or backbone. Invertebrates differ, however, in size, shape and body covering.


SIZE: Most invertebrates are very small, only a few centimetres, but some are enormous, like the giant squid.

Look! This is a picture of a giant squid found near Japan:

Click on the image to find out more!

Read this facts about the giant squid:

BODY SHAPE: Most invertebrates are symmetrical.

Bilateral symmetry: Two identical halves or planes. For example: insects.
In this picture, you can see a ladybug.
 

 

Radial symmetry: Several planes of symmetry. For example: starfish.

 

 

Asymmetry: The body has no symmetry. It is irregular. For example: sponges.

 

 

Look at the following diagram which shows the different kinds of symmetry:

 

(A) Bilateria (bilateral symmetry). (B) Radiolarians (radial symmetry).

From Biology Demystified: A Self-Teaching Guide. Copyright © 2003 by The McGraw-Hill Companies, Inc. All Rights Reserved.

 

BODY COVERING: Some invertebrate bodies are protected by shells orexoskeletons (like scorpions or snails), but others have no covering.


WHERE AND HOW INVERTEBRATES LIVE

Invertebrates differ in their habitat and their movement.

• Many invertebrates live in the ocean, but some live in fresh water, and others on land.
• Most invertebrates can move. However, some do not move: they attach themselves to rocks or the ocean floor. Parasites live inside other animals and harm them.

Most invertebrates are oviparous. A larva hatches from an egg. At first, it does not look like the adult. Later, its body changes.


INVERTEBRATE GROUPS

There are many groups of invertebrates. For example:

 SPONGES
They have irregular bodies and no symmetry. They cannot move around. They attach themselves to rocks or the ocean floor. They filter sea water and retain the nutritive substances for food.

CNIDARIANS
They have jelly-like bodies, some with radial symmetry. They have tentacles that sting you. They are marine animals. Some, like coral and sea anemone, attach themselves to rocks. Others, such as medusas, can move about.

WORMS
They have soft bodies with bilateral symmetry. Some are cilindrical, but others are flat. Some worms are aquatic; others are terrestrial. Many are parasites.

ECHINODERMS
They have five-way symmetry. They have a skeleton made of hard plates, often with spines. They are covered by a thin skin. All are marine animals.

ARTHROPODS
They have bilateral symmetry. Their bodies are totally coveredby an articulated exoskeleton, like armour. Some are aquatic; otheres are terrestrial.

MOLLUSKS
They have a soft body with bilateral symmetry. Many are covered with one or two shells.

 

Let's watch a movie for reviewing all the information! 

 

 

 

 

 

MICROORGANISMS

HOW LIVING THINGS ARE ORGANIZED

Multicellular living things are very organized. In fact, levels of organization exist:

The smallest living unit that makes up a living thing is the CELL.
Look at these human cells:

CELLS group together to form tissues.

TISSUES are made up of similar cells that carry out a common function. For example, muscle tissue is made up of hundreds of muscle cells grouped together.

 Tissues form ORGANS. Organs are made up of a group of tissues that work together to carry out a common function. For example, muscles and bones are organs.

Organs form SYSTEMS. Systems are made up of a group of organs that work together to carry out a common function. For example, the skeletal system is made up of bones.

When all systems work together, they form an ORGANISM. An organism is a COMPLETE LIVING THING.

The Internal Organization of Living Things

What is a cell?

Living things are made up of a large number of very small units called CELLS.

A cell is the smallest living unit that makes up a living thing.

Most cells are very small, so we need a microscope to see them.

The number of cells in a living thing varies.

• Some living things are made up of a single cell. They are called UNICELLULAR: they can only be seen with a microscope. For example: a paramecium.

• Other living things are made up of many cells: they are called MULTICELLULAR. For example: an elephant.

What are cells like?

Cells are living things. This means that, like other living things, they carry out the life processes of nutrition, reproduction and sensitivity.

However, not all cells are alike. They differ in shape, in size and in the tasks they carry out. For example, skin cells are differente from bone cells.

Cells have three main parts:

• The membrane is a covering that surrounds the cell, and separates it from the exterior.
• The nucleus is the part that controls the function of the cell.
• The cytoplasm is the space between the nucleus and the membrane.

Plant cells also have a hard cell wall around the membrane.
         

             Animal Cell                                      Plant Cell

Click on the image above to learn more about each cell part.

Now, click the following image. Read the tutorial, play the game and answer the quiz questions.

WHAT LIVING THINGS ARE LIKE

PRINCIPAL CHARACTERISTICS

We can recognize living things because they share the following characteristics:

• They are born. All living things come from other living things.

 

 Chicks are hatching from eggs.

• They eat. All living things need food. The type of food may vary.

The squirrel is eating a nut.

• They grow. All living things increase in size during their lifetime. Sometimes they change appearance.

Plants growing.

 

Click on the image below to play a game about "Growth".

 

• They react. Living things can perceive what is going on around them, and they react to what they perceive.

A zebra running away from a hungry lion.

• They reproduce. Living things can create offspring similar to themselves.

A mother, a father and their baby.

• They die. At some time, all living things stop functioning and cease to live.

Dead trees in a desert.

LIVING AND NONLIVING THINGS

Let's start by singing a song about living and nonliving things. Listen and sing along!

Does it breathe air?

Does it move or grow?

Does it need food or water?

If "yes", then you know... It's a living thing. (x2)

 

Does it breathe air?

Does it move or grow?

Does it need food or water?

If "no", then you know... It's a nonliving thing. (x2)

 

Now try this game and sort things into the right place. Click on the image below to start.

 

 

 

In nature there are nonliving things and living things.

 

Rocks, air and wind are nonliving things.

 

People animals and plants are living things. 



 

 

Now, click on the image below and learn more about living and nonliving things.

 

Work with the Blog Worksheet. Complete the exercises. See you next class!

HOW MANY PLANETS?

Let's sing and learn the names of the planets. Watch the video and sing along!

SCIENCE 2013

Welcome back to school!

Let's start this year by learning about our Solar System.

Stars and planets have a round shape called sphere.
Stars are balls of gases that produce heat and light. Our solar system contains a star called the Sun.

Planets are made of rock, gas, and sometimes frozen liquid. Some planets have natural satellites called moons that travel around them. Our solar system has eight planets.

A satellite is an object that travels around a larger object.

Click on the images below and play the games to learn more about the Sun, the Earth and the Moon.