1. Invertebrates and Vertebrates

3. Invertebrates

4. 1. Body symmetry Some are asymmetrical e.g. sponges
Radially symmetrical e.g. jelly fish, starfish
Bilaterally symmetrical e.g. snail, sea hare

5. 2. Segmentation Body of animals divided into sections or segments
Insects have three segments – head, thorax and abdomen
Earthworm, marine worms

6. 3. Support of the body Support and protection
Sponge – body is supported by jelly like material
Roundworms have thick skin
Crab and lobsters have exoskeleton

7. 4. Respiratory and circulatory systems
Respiratory system – exchange of gases
Respiration requires oxygen
E.g. gills in lobsters
Tracheae (network of tubes) in insects
Circulatory system - transport substances
Closed circulatory system – fluid inside tubes
E.g annelids (earthworm)
Open circulatory system – fluid moves in open spaces of body
E.g. mollusks (snail)

8. 5. Digestive and excretory systems
Digestion – conversion of food from large particles/molecules to smaller ones
After consumption, food is digested and simpler molecules are transported to cells
Oxidation of food in cell (cellular respiration) produces energy
Invertebrates have relatively simple digestive systems

9. 6. Digestive and excretory systems
Excretory system – get rid of the waste materials
As body uses nutrients and performs reactions, wastes are formed
Excretory system eliminates these wastes along with excess of water
In some invertebrates, the digestive system removes wastes
In others, there is a separate excretory system

10. 7. Nervous system
Nervous system – sense and respond (process information)
Receive and send electrical signals that control functions of the body
Several invertebrates have a specialized area called “brain”
Brain acts a control center
In addition to brain, sense organs are also present
Sense organs collect information (e.g. light)

11. Nervous system

12. 8. Reproduction Budding (e.g. hydra) Fragmentation (e.g. planaria)
Sexual reproduction (e.g. insects)

13. 9. Development Development – various stages of life
Metamorphosis – series of developmental changes in the life cycle (insects)
Many insects reproduce sexually and lay eggs
The insect hatched from egg and undergo various distinct stages of life cycle
Metamorphosis (two types)
Complete metamorphosis - 4 stages (Egg  Larva  Pupa  Adult)
Incomplete metamorphosis – 3 stages (Egg  Nymph  Adult)

14. Development

15. Development
Incomplete metamorphosis

16. Vertebrates

17. Vertebrates Land, fresh water, oceans Swim, crawl, burrow, hop, fly
Have a backbone
Head (brain, sensory organs)
Presence of cartilage (and replacement by bone during development)

18. 1. Body symmetry All are bilaterally symmetrical
Head is distinct from rest of the body
Four regions of body (dorsal, ventral, anterior, posterior)

19. 2. Body coverings Body is covered by skin
Protection from outer environment
Varies in structure
Reptiles (scales), fish (scales),
Mucus in amphibians and fish
Birds (feathers), mammals (fur, hair)
Help maintaining body temperature
Colors and patterns (camouflage and recognition)

20. Body coverings

21. 3. Support of body Presence of endoskeleton
Skull, backbone, limb bones
Skull (brain), vertebrae (spinal cord)
Attachment of muscles – movement

22. 4. Respiratory system Breathing and exchange of gases
Two types of systems – gills (water) and lungs (land)
Presence of blood vessels in these organs

23. 5. Circulatory system Transport of materials Closed circulatory system
Blood, vessels and pump (heart)
Arteries, veins and capillaries
Heart pumps blood
Oxygenation (gills/lungs)
Carbon dioxide removal
Nutrients and other substances
Waste removal (kidneys)

24. 6. Digestive and excretory systems
Digestive tract – long tube like digestive system
Direct swallowing and chewing
Food passes on to stomach (acid and enzymes)
Small intestine (absorption of nutrients , blood vessels present)
Large intestine (water absorption, undigested material is converted to faeces)
Nitrogenous (urea) and other wastes
Kidneys combine wastes with water to produce urine

25. Digestive and excretory systems

26. 7. Nervous system Processing information (sense and respond)
Electrical signals
Brain control center, spinal cord and nerves
Sensory organs
Sensory nerves (body to brain), motor nerves (brain to body)
Size of brain and learning

27. 8. Reproduction and development
Sexual reproduction
Fertilization - male (sperm) and female cells (egg)
Fertilized egg divides to produce multicellular stage
Differentiation of cells (specialization)
Different cells perform different function

28. 9. Reproduction and development
Amphibians and some fish – larva hatches in water, develops into an adult organism
Reptiles, birds and mammals do not have larval stage
Embryo is protected by membranes
Eggs of reptiles, birds and some mammals have a shell
Most mammals do not lay eggs (give birth to offspring)
Offspring develops inside the body of female individual
Embryos of different species are similar to each other at early stages of development
Embryos begin to look more like the adults of their own species as they develop

29. Reproduction and development

30. 10. Parental care Number of offspring and parental care
Birds and mammals have few offspring
Feeding and protection
Parental care increases chances of surviving