Chapter 3 Life Cycles

Lesson 1 Plant Life Cycles

embryo-germinate-life cycle-life span-

Lesson 1 Plant Life Cycles

embryo- a plant or animal in the earliest stages of development

germinate- to begin growing a new plant

life cycle- a series life span-

Life Cycle of a Flowering Plant• 1. Seed is planted• 2. Seed sprouts and grows into a tree• 3. Tree flowers and releases its own seeds• 4. One day the tree will die

The life cycle of all living things is• 1. Birth• 2. Development into adult• 3. Reproduction• 4. Death

Parts of a Flower• Petals: attracts birds and bees and other insects

• Stamen: Produces pollen which is needed to form seeds

• Pistil: Pollen collects here. Seeds are produced in the lower part of the pistil

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Wind, water, or animals move pollen from the stamens to the

pistil (seeds produced). The petals attract animals

Seeds contain an embryo.

Some seeds will land in new places where they germinate

Cycle begins again

Life Span of Plants

The life span begins when a seed germinates and ends with the death of the plant

In similar organisms, the smaller kinds usually have shorter life spans than the larger kinds.

*not always true

Lesson 2 ~ Animal Life Cycles

Adult- a fully grown, mature, adultEgg- the first stage in the life cycle of most

animalsLarva- a worm-like form and the second

stage of complete metamorphosisMetamorphosis- the process in which an

animal changes in different stages of its life cycle

Nymph- the second stage of incomplete metamorphosis

Metamorphosis

• An egg is the first stage in the life cycle of most animals

• All birds, most fish, reptiles, amphibians, and insects lay eggs.

Reptiles

• cold-blooded• dry, scaly skin• lay many eggs• breathe through lungs• short legs• vertebrates

*Draw a picture of a reptile on your chart*

Amphibians• 2 lives ~ water and land• live in warm wet areas• cold-blooded• bones inside their bodies/ vertebrate • moist skin• no scales, hair, or feathers• Go through metamorphosis

grow legsdevelop lungs

*Draw a picture of an amphibian on your chart*

Some insects go through complete metamorphosis

and some go through incomplete metamorphosis.

Complete Metamorphosis (4 changes)Egg ~ Larva ~ Pupa ~ Adult

(looks different in each stage)

Incomplete Metamorphosis (3 changes)Egg ~ Nymph ~ Adult

Complete Metamorphosis

Incomplete Metamorphosis

Insects

• have 6 legs• made of 3 parts• one or two pairs of wings• cold blooded• invertebrates• lay many eggs

*Draw an insect on your chart*

Birds

• only animal with feathers• lay eggs• 2 legs and 2 wings• warm blooded• vertebrates

*Draw a picture of a bird on your chart*

Fish

• scales• most are cold-blooded• lay eggs• fins NOT legs• live in water• breathe through gills• vertebrates

*Draw a picture of a fish*

Mammals

• have fur or hair• babies drink milk from their mom• vertebrates• 4 limbs• breathe through lungs• warm-blooded

*Draw a picture of a mammal*

Life Cycles and Life Spans*Just as life cycles vary, so do life

spans*

• In general smaller animals have shorter life spans than larger animals of the same kind

• There are some exceptions where smaller animals live longer– ex. the human lives longer than an

elephant and is much smaller

Lesson 3 ~ Parents and Offspring

inherit- to receive traits from a parent

trait- a feature or characteristic of a living thing

Look Alikes

• Young living things resemble their parents• Features such as color and length of fur are

examples of traits

• Traits of humans include eye color, hair color, shape of the eyes, nose, and mouth

• Traits of birds include feather color and the shape of the beak and feet

• Traits of a plant include shape of leaves, the color of its flowers, and type of roots it has

Inherited Traits

• Young organisms usually inherit many traits from their parents

• Inherited traits are passed from parents to offspring

• Some inherited traits may change slightly when they are passed on

• Organisms with two parents inherit traits from both parents

• Not all organisms resemble their parents at birth. – like a tadpole and frogs– after metamorphosis it begins to look like its

parents