Life Cycles

What is a lifecycle? The different stages an animal or plant goes through during its life. In plants this includes: Pollination Fertilisation Fruit development Dispersal of seeds Germination What stages might this include?

Animal Lifecycles Animal life cycles include: Birth Growth Reproduction Death There are many types of species of animals on the planet. Fish Amphibians Reptiles Birds Mammals Invertebrates (eg Insects)

Species Groups These are the groups we will be looking at in more detail today: Mammals Reptiles Amphibians Insects

Mammals Reproduce through sexual reproduction Most mammals have very similar life cycles, with the individuals going through similar stages of development: Females give birth to live young Young looks like a miniature version of the adult Female provides milk for the young to grow and develop Adults take care of the young Reproduce through sexual reproduction involving sperm and egg.

Lifecycle of a Mammal-Humans

Lifecycle of a Mammal-Lion

Reptiles Most reptiles lay eggs Young looks like a miniature version of the adult Generally, no parental care is given – the eggs/young are left to look after themselves Most reptiles reproduce through internal sexual reproduction, involving sperm and eggs

Lifecycle of a Crocodile

Amphibians Most amphibians lay eggs After hatching, amphibians usually go through a very different physical form (tadpole) before looking like an adult Tadpoles and young frogs are not usually given any parental care Most amphibians reproduce through external sexual reproduction, involving sperm and eggs

Lifecycle of a Frog

Insects There are two different types of insect life cycle: Incomplete metamorphosis Complete metamorphosis. Metamorphosis means a change of form. This means that the young look very different from the adult.

Incomplete Metamorphosis This is shown by the less highly developed insects. The life cycle shows only three stages:- EGG NYMPH- resembles a miniature adult but is not able to reproduce ADULT This life cycle has the disadvantage that both nymph and adult often share the same food source. Therefore they can be in direct competition with one another for food. The advantage is that the vulnerable pupal phase is avoided. Examples include dragonflies, grasshoppers, earwigs and cockroaches.

Lifecycle of a Grasshopper

Complete Metamorphosis This is shown by the more highly developed insects. The life cycle shows four stages: EGG LARVA- or caterpillar is the growth phase PUPA- or chrysalis is a stage of internal reorganisation ADULT Usually the larva and adult use different food sources. Therefore they are not in direct competition. This is a distinct advantage as more individuals of the species can be fed. Examples include butterflies, moths, bees, wasps, true flies and many other insects, including beetles:-

Lifecycle of the Monarch Butterfly

Amazing Lifecycles Some baby spiders (spiderlings) eat the mother spiders as they grow up. Some female spiders eat the male after mating. Some parasitic wasps lay their eggs in the head of ants. When the eggs hatch the baby wasps eats the ants from the inside out. Black lace-weaver cannibalise their mother Eucharitid wasps are parasitic Black widow devours her mate

Amazing Lifecycles- Kangaroo Kangaroos have very tiny babies called joeys. The joey is born at a very immature stage and is only about 2cm long. After their birth they crawl into the mother’s pouch where they feed and grow and continue to develop. These mammals are called marsupials. Examples of other marsupials are koalas, wombats, opossums the Tasmanian devils

Life spans A life span begins with an animal’s birth and ends with its death. Animal Life span Vampire bat 14 years Chimpanzee 44 years Kangaroo 6 years Crocodile 70 + years Dog 20 years Butterfly 1 month Grasshopper 1 year Frog 11 years Lion 12 years Owl 60 years Elephant Human lifespan can vary greatly depending on where a person lives. In the UK a person is expected to live for about 80 years. Life span of animals in captivity is longer.

Task Write a report on the life cycle of an animal of your choice that you have researched. Complete for homework. Make sure you include the following: Name the different stages of it’s lifecycle with a description of each stage. Information about how the animal reproduces. Lifespan 2 more interesting facts about your animal. Pictures and good presentation. Good spelling and grammar.