Unit 1: CLASSIFICATION OF LIVING THINGS

A. What Are Living Things Made Of?

1. Basic Cell Structure

• All living things are made up of cells.
• Cells hold all of the equipment and information necessary to keep an organism alive.
• Each type of cell performs a different function.
• There are nerve cells in your brain that receive messages, and others that send messages.
• There are blood cells that carry oxygen around the body, and others that protect the body against disease.
• The smaller parts within a cell are called organelles.

2. Animal Cell Structure (ANIMAL CELL):

• An animal cell looks like this:
• The main parts of the cell are the nucleus, cytoplasm, cell membrane, and vacuole.
• The nucleus is the control centre of the cell.
• The nucleus also controls the cell’s growth and reproduction.
• The cytoplasm helps to move materials around the cell and also dissolves waste.
• The vacuole is a space in the cytoplasm that can contain either air, liquid, or food.
• The cell membrane acts as a barrier to the world outside the cell.
• It lets the things in and out of the cell and stops dangerous things from getting in.

3. Plant vs Animal Cell Differences

• Cells of all living things (except for animals) have cell walls.
• Plant cells are similar to animal cells.
• However, they have three parts that an animal cell doesn’t have.
  • They have a cell wall that provides more protection than just a cell membrane.
  • They have chloroplasts that contain the chlorophyll that is required for photosynthesis.
  • They have a vacuole that stores things like water, food, and waste.

B. Universal Classification System

1. The Five Kingdom System

• To make the study of living things easier, they have been carefully classified into 5 kingdoms.
• The classification is based on their cell type, the complexity of their bodies, and how they receive nutrition.
• The kingdoms are Monera, Protista, Fungi, Plants, Animals.

II. MAJOR ANIMAL DIVISIONS

A. Primary Animal Classification

1. Structural-Based Classification

• Animals are divided into groups according to their structural features.
• That means their physical make-up.
• Firstly, animals are divided into vertebrates and invertebrates.

B. Complete Animal Kingdom Hierarchy

Animal kingdom

VERTEBRATE ANIMALS

A. Mammals

What Makes a Mammal?

Mammals have three main common characteristics:
– They are warm-blooded
– The females are able to feed their young with milk from their mammary glands.
– They have hair or fur.

Examples of Mammals
Cats, dogs, rats, kangaroos, koalas, opossums, Australian platypus and the echidna are all examples of different types of mammals.

Advantages of Mammalian Traits

– Warm-Blooded Advantage

• Being warm-blooded means that the animals can keep their body temperature the same, even when the temperature around them changes.
• This is an advantage because it means mammals are able to be active in any temperature.

– Hair/Fur Benefits

• Having hair or fur not only provides an animal with warmth, the colour of the hair or fur can help camouflage a mammal so that it can hide from predators.

5. Special Mammal Facts

• DID YOU REALLY?
• There is one mammal that can fly.
• Do you know what it is?
• It’s a bat

B. Birds

1. Bird Classification

• Birds

2. Seven Main Bird Characteristics

• Birds have several common characteristics:
• They are warm-blooded.
• They lay eggs with hard shells.
• They have feathers and wings.
• They have scales but only on their legs and feet.
• They breathe through lungs.
• They have a beak but no teeth.
• They have a furcula, which is also known as a wishbone.

3. The Wishbone Structure and Function

• Have you ever seen a bird’s wishbone?
• It looks like this.
• Why do you think a bird has a wishbone?
• The wishbone protects the bird’s chest from the force of the wings.

4. Flightless Birds

• Not all birds can fly.
• The flightless birds include ostriches, emus, rheas, penguins, cassowaries, and kiwis.
• ostrich
• kiwi
• penguin

5. Bird Study Activities

• In your NOTEBOOK…
• Make a list of birds that live in Pakistan.
• Draw your favourite bird from the list.

6. Amazing Bird Facts

• AMAZING SCIENTIFIC FACT
• The hummingbird can fly backwards.
• hummingbird

C. Reptiles

1. Reptile Classification

• Reptiles

2. Seven Main Reptile Characteristics

• Reptiles have several common characteristics:
• They are cold-blooded.
• They lay eggs with leathery, waterproof shells.
• They have four legs (except for snakes).
• They have scales instead of hair or fur.
• They breathe through lungs.
• They have external ear openings (except for snakes).

3. Examples of Reptiles

• Crocodiles, alligators, lizards, snakes, tortoises, and turtles are reptiles.

4. Reptiles in Earth’s History

DINOSAURS

• DINOSAURS
• Reptiles once ruled the Earth.
• Dinosaurs were reptiles and they were the dominant vertebrate for more than 100 million years.

Evolution Connection

• DID you READER?
• Modern day birds have evolved from reptiles.
• Many of today’s birds can be traced back to the dinosaurs.

5. Study Activities

• In your NOTEBOOK…
• Write down three main differences between mammals and reptiles.

6. Research Questions

• FIND OUT!
• What is the difference between
• a turtle and a tortoise?
• an alligator and a crocodile?

D. Fish

1. Fish Classification

• Fish

2. Six Main Fish Characteristics

• Fish have several common characteristics:
• They live in water.
• They breathe through gills.
• Most have scales.
• Most lay eggs.
• Most have fins to help them move through the water.
• They are cold-blooded.

3. How Fish Get Oxygen

• Although fish live in water, they need oxygen just like animals on land.
• Fish get their oxygen from the water.
• They take in water through their mouth and pass the water over the gills where the oxygen is extracted.

4. Unique Fish Facts

• AMAZING SCIENTIFIC FACT
• There is one type of fish that can swim upright—the seahorse.

E. Amphibians

1. Amphibian Classification

• Amphibians

2. Five Main Amphibian Characteristics

• Amphibians have several common characteristics:
• They have thin skins.
• They begin life in the water and then live on land.
• Adult females return to the water to lay their eggs.
• They do not have scales or claws.
• They are cold-blooded.

3. Examples of Amphibians

• Frog, toads, salamanders, and newts are amphibians.
• Frogs, toads, salamanders, and newts are amphibians.
• frog
• toad
• salamander
• newt

4. Special Amphibian Abilities

• AMAZING SCIENTIFIC FACT
• Salamanders are able to regrow lost tails and other body parts.
• salamander
• fish

IV. INVERTEBRATE ANIMALS (DETAILED STUDY)

A. Arthropods – The Dominant Invertebrates

1. Arthropod Overview

• Invertebrates
• Arthropods
• More than three-quarters of all animal species are arthropods.
• They are found everywhere on Earth—on land, in trees, in water, and underground.

2. Arthropods in the Food Chain

• Arthropods are the major source of food for most other animals.
• They are eaten by birds, fish, some mammals, and even other arthropods.
• Some plants also eat them.

3. Arthropod Classification Groups

• To help study arthropods, scientists have divided them into five main groups: insects (beetles, ants), arachnids (spider, scorpion), crustaceans (crabs, lobsters), centipedes, and millipedes.
• To help study arthropods, scientists have divided them into five main groups: insects (beetles, ants), arachnids (spider, scorpion), crustaceans (crabs, lobsters), centipedes, and millipedes

B. Insects – The Most Numerous Animals

1. Insect Diversity

• INSECTS
• About one million species of insects have been identified on Earth with probably more than that number still not identified.

2. Three Universal Insect Characteristics

• All insects share three main characteristics:
• a body divided into three sections (head, thorax, abdomen)
• one pair of antennae
• three pairs of legs on their thorax.

3. Common Insect Examples

• Bectles, ants, ladybirds, flies, mosquitoes, and grasshoppers are examples of insects.

4. Deadly Insect Facts

• MAZING SCIENTIFIC FACT
• The world’s most deadly animal is an insect.
• The mosquito kills more humans than any other animal by the spreading of diseases.

C. Other Major Invertebrate Groups

1. Introduction to Additional Invertebrates

• Other invertebrates
• We haven’t quite finished yet.
• There are a few more types of invertebrates that I want to tell you about.

2. Molluscs – The Largest Invertebrate Group

Basic Mollusc Information

• Molluscs
• Some molluscs live on land but most live in shallow water.
• They are the largest group of invertebrates.

Mollusc Body Structure

• Their bodies are divided into four regions: head, body cavity, muscular foot, and a mantle.
• The head and foot regions are most easily observable parts of the molluscs.

Examples of Molluscs

• Oysters, snails, octopuses, and clams are examples of molluscs.

3. Sponges – The Simplest Animals

Basic Sponge Characteristics

• Sponges
• Sponges are the simplest form of animal.
• They do not have a nervous system or any muscles.
• They cannot move on their own and most live on the seafloor.

How Sponges Feed

• Because they cannot move, they can’t hunt for food.
• Instead they live on the water that flows through tiny holes in their body.
• The water contains the oxygen and nourishment they need to survive.

4. Worms – Three Main Types

Worm Classification and Structure

• Worms
• Worms are divided into three groups, most commonly known as segmented worms, flatworms, and roundworms.
• They have soft, long, tube-like bodies divided into segments.
• They do not have arms or legs.
• Some worms are microscopically small while others can grow much longer.

Types of Worms

• segmented worm
• flatworm
• roundworm

Worm Senses and Habitats

• Many worms have sense organs to detect chemical changes in their environments, and some have light-sensing organs.
• Worms live in various habitats.
• Some are parasites and live in the bodies of other animals.
• Some worms are decomposers, and others are predators.

5. Echinoderms – Star-Shaped Marine Animals

Basic Echinoderm Characteristics

• Echinoderms
• Echinoderms live in water.
• They all have star- like appearance.

Examples and Special Systems

• Starfish and sea urchins are examples of echinoderms.
• Echinoderms are marine animals and possess a very unique water vascular system that, not only allows them to transport food and water in their bodies, but also helps them in movement.
• starfish
• sea urchin
• AFORD

6. Cnidarians – Tentacled Water Animals

Basic Cnidarian Structure

• Childarians
• Childarians live in water.
• They have a bag-like body which has tentacles coming off it.

Examples of Cnidarians

• Childarians include jellyfish and coral.

Dangerous Cnidarian Facts

• AMAZING SCIENTIFIC FACT
• The most deadly jellyfish is the box jellyfish.
• Each of its tentacles has about half a million poisonous, needle-like spines.

V. PLANT KINGDOM

A. Plant Classification System

1. Plant Kingdom Overview

• Classification of plants
• Over 80% of the plant kingdom is composed of the flowering plants (Angiosperms).
• They produce flowers and fruits which contain seeds in them.
• Angiosperms are further divided into monocotyledons and dicotyledons.

B. Monocotyledons (Monocots)

1. Definition and Seed Structure

• The seeds of flowering plants contain either one or two cotyledons.
• Those with one cotyledon are called monocots.
• The maize seed is a monocot.

2. Examples of Monocot Plants

• Onion plants (above) and sugarcane plants (below) are examples of monocotyledons.
• Other examples of monocot plants include maize, rice, lilly, and wheat.
• lilly is a monocot

3. Monocot Characteristics

Leaf Structure

• A monocot plant such as Maize, onion, rice, sugarcane, lilly, and wheat has narrow leaves with parallel veins on them.

Flower Structure

• Their flowers have petals which are either 3 or multiples of 3 (i.e. 3, 6, 9, etc).

C. Dicotyledons (Dicots)

1. Definition and Seed Structure

• Those with two cotyledons are called dicots.
• The chickpea is a dicot.

2. Examples of Dicot Plants

• Cabbages (above) and tomato plants (below) are examples of dicotyledons.
• Other examples of dicot plants include chickpea, apple, and peach tree.
• apple is a dicot

3. Dicot Characteristics

Leaf Structure

• A dicot plant such as Chickpea, tomato, cabbage, apple and peach tree, has broader leaves with net like veins on them.

Flower Structure

• Their flowers have petals which are either 4 (or 5) in number or multiples of 4 or 5.

D. Plant Development

1. Germination Differences

• When they germinate, the difference between monocots and dicots can be seen in their leaves.

2. (Comparison of monocots and dicots):

[This serves as a summary section for the comparison already detailed above]

VI. BIODIVERSITY AND ENVIRONMENTAL CONCERNS

A. Understanding Biodiversity

1. Definition of Biodiversity

• BIODIVERSITY
• The existence of a large number of different kinds of animals and plants which make a balanced environment, is known as biodiversity.

B. Human Impact on Ecosystems

1. Human Activities Affecting Nature

• Human effects on biodiversity
• Humans are the only living things which often go into other ecosystems.
• Humans use rivers, streams, and oceans to find food.
• Humans cut down trees in forests to make houses, furniture, and other things.
• Humans dump garbage everywhere and add poisonous chemicals to land, air, and water.

2. Consequences of Human Actions

• All these actions result in pollution and destruction of ecosystems.
• This increases competition for resources (such as fresh drinking water) between living things.
• This results in many of them dying off, reducing biodiversity.

C. Species in Danger

1. Endangered vs Extinct

Definitions

• Endangered and extinct
• If animals and plants lose the elements that help them to survive, they can become endangered or extinct.
• Endangered means their numbers are declining.
• Extinct means they have disappeared altogether.

Causes of Endangerment

• Sometimes human activity causes them to become endangered or extinct.
• Overlogging, deforestation, overuse of resources, and pollution are leading causes of habitat destruction leading to extinction.

2. Endangered Species in Pakistan

• There are several endangered species in Pakistan.
• They include the Indus River dolphin, Markhor, and blackbuck.
• Snow leopards in Pakistan are endangered because humans are hunting them and destroying their habitat.

3. Student Research Activity

• FIND OUT MORE
• Write about one endangered species.
• You will have to find out about it in a book or online.

4. Examples of Extinct Species

• These animals were endangered once, but are extinct now.
• Extinct means there are none of them left on Earth.
• dodo – great auk – dinosaurs (all types) – quagga – Tasmanian tiger

D. Conservation Efforts

1. Understanding Conservation

• Conserving endangered species
• An endangered species is a group of living things that is at risk of dying out completely.
• If something is not done to protect them, they will soon be lost to the Earth forever.

2. Causes of Endangerment

• Some species are endangered because of human activity.
• Some species are endangered for other reasons.

3. Human Responsibility

• Humans are in a position to help endangered species survive.

4. Conservation Methods

Habitat Protection

• STOP DESTROYING HABITATS
• Some species are endangered because humans have destroyed their habitats.
• Chopping down trees in forests and clearing land for agriculture destroys natural habitats and puts species at risk.