3.4 Anamals are adapted

Natural sciences

Grade 8

Diversity

Module 27

Survival: how animals are adapted to their way of living

Types of Adaptation

There are different types of adaptation. In this learning unit we shall be looking at adaptations that have to do with ways of feeding and protection by means of colour.

A. Adaptations with regard to Food

• To obtain food
• To ingest food

B. Adaptations with regard to colour

• For self-protection

A. Food-related Adaptation

All animals require food to remain alive. This food must firstly be found and the animals’ bodies must, be adapted to ingest and digest the food.

FEEDING comprises both ingestion and digestion.

Activity: TO USE PRIOR KNOWLEDGE TO GAIN NEW KNOWLEDGE

The most common adaptations related to feeding are:( Complete from prior knowledge)

HERBIVORES

CARNIVORES

OMNIVORES

HERBIVORES

• Plant material does not provide much nutrient value. Herbivores therefore have to eat large amounts of leaf material.
• They need large stomachs (gizzards) for storing these amounts of food – some animals ruminate.
• Leaves may be hard and thorny and have rough stems and an unpleasant taste.
• Herbivores need powerful jaws and molars.

Name two examples of herbivores from each of the following categories:

1. mammals

2. birds

3. insects

CARNIVORES:

• Meat has better nutrient value but it has to be hunted and caught:
• Carnivores need to be fast and strong and have claws or powerful beaks.
• They need sharp teeth and powerful jaw muscles.
• They do not need to store large amounts of food in the alimentary canal.

Name two examples of carnivores from each of the following categories:

1. mammals

2. birds

3. insects

OMNIVORES:

• As they eat both plant and animal material, they need to be adapted to eat both types of food: sharp as well as grinding teeth; well-developed digestive system; ability to catch prey.

Name two examples of omnivores from each of the following categories:

1. mammals

2. birds

3. insects

The most common adaptation in this regard is related to the TEETH in the skull of the animal.

• There are FOUR kinds of teeth: Incisors, Canines, Premolars, Molars.

Supply the function of each kind of tooth with the different ways of feeding of herbivores, carnivores and omnivores.

HERBIVORES: have to cut, gnaw and grind and therefore need strong incisors and molars.

CARNIVORES: have to bite and tear and therefore need strong incisors and canines. Molars are shaped like canines and not like grinders.

OMNIVORES: all teeth work equally well and are equally developed

[LO 2.1; 2.4]

Activity: to identify correctly

Teeth

Study the illustrations and answer the questions that follow:

1. Which drawing represents a molar? Explain your choice:

2. To which kind of animal might the molar belong?

3. Identify the other tooth and explain your choice:

ASSIGNMENT:

We have examined the ways in which animal teeth are adapted to particular ways of feeding. Draw upon your own knowledge of cats, lions and leopards and describe the ways in which the bodies of carnivores are adapted to their manner of feeding.

[LO 2.4]

B. Colour Adaptations

Each animal in nature is a possible PREY to another organism. They need to protect themselves in any way possible for the sake of SURVIVAL.

We are going to look at COLOUR ADAPTATION to illustrate ways of fooling enemies:

• Camouflage (colour adaptation to become unrecognisable)
• Warnings (colour adaptation to warn of poison or a bad taste)
• Mimicry (copying)

  

Camouflage

The animal seeks to blend into its natural environment by means of:

colour, e.g. green grasshoppers on grass

patterns, e.g. moth on the bark of a tree

stripes, e.g. some frogs among reeds

spots, e.g. the wings of a nightjar

colour changes, e.g. chameleons or fish

many marine animals have shiny white bellies and dark backs

colour changes that are seasonal, e.g. the polar fox

colour adaptation that accompanies adaptation of shape, e.g. stick insects or inch-worms

Warning colouring

• The animal has conspicuously bright colours to warn against bad taste, poisonousness or an unpleasant substance.
• This normally comprises red, yellow or white colouring against black.
• Examples:

Elegant grasshopper

Striped mongoose

Ladybirds

Wasps

• Other creatures, like some moths (e.g. the pine tree emperor moth) have large spots on its wings that look like eyes to frighten off predators.

Mimicry

• With this adaptation, one creature normally mimics another species that has survived successfully. Insects, especially, make use of this strategy.
• One insect provides the MODEL
• The other is the MIMIC
• The swallowtail butterfly (b) is a good example of a mimic. The milkweed butterfly (African monarch) (a) is the model.

  

• Another example is that of flies that mimic bees.

Activity: TO IDENTIFY EXAMPLES OF COLOUR ADAPTATION

Study the sketches and indicate the relevant type of adaptation

Assessment of APPLICATION:

Could you identify the adaptations correctly?

[LO 2.4]

Assessment

Learning outcomes 2: Constructing Science Knowledge

The learner will know and be able to interpret and apply scientific, technological and environmental knowledge.

This is evident when the learner

2.1 is able to recall meaningful information;

2.4 is able to apply knowledge.

Memorandum

Activity: IDENTIFICATION – teeth and dentition

• Obtain examples of skulls for the lesson

Activity: IDENTIFY - COLOUR ADAPTATION

• Cutting and pasting activity.