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Life Science
4th Grade Review
How Animals Meet Their Needs
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Environment – everything that surrounds and affects and
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Climate – average temperature and rainfall
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Oxygen – one of many gases in air
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Food
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Water
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Shelter – a place where an animal is protected from other animals
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Need to have young – Most care for their young until the are old
animals (living and nonliving)
or weather (#36)
enough to live on their own
– Metamorphosis – change from an egg to a butterfly
Animal Adaptations: Body
Parts
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Adaptation – body part or behavior that helps an
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Birds (#55)
animal meet its needs in its environment
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Beak – food
Eyes
Claws
Feathers – warm, dry, and flight
Hollow bones
Flightless birds – running, swimming
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Body Covering (fur, hair, scales)
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Color & Shape
– Camouflage – animal’s color or pattern that helps it blend in
with its surroundings
– Mimicry – animal looks very much like another animal or object
Animal Adaptations: Behaviors
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Instinct – behavior that an animal begins life with
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Migration – movement of a group of one type of
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Hibernation – period when an animal goes into a
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Learned behavior – taught by adults (hunting,
animal from one region to anther and back again
(behavioral)
long, deep “sleep”
communication, building nests)
Life Support for Plants
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Basic Needs
– Air (carbon dioxide)
– Nutrients ( substances, such as minerals, that all living things
need to grow)
– Water (taken from the roots)
– Light (not too shaded) (#33)
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Photosynthesis – making food in a plant’s
leaves (#26)
– Chlorophyll – makes a plant green
– Sunlight starts the food-making process
– Carbon dioxide (taken through leaves) and water (taken through
the roots) make sugar
– Oxygen is waste
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Other Adaptations – (water lilies, vines, desert plants)
Functions of Plant Parts
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Leaves – carry out photosynthesis
– Symmetrical – when divided in half, two parts are the same
– Transpiration – giving off of water by plant parts
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Stems (soft & flexible or stiff & woody) – support a
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Roots – Hold plants in the soil and take in water and
plant and give it shape
nutrients
– Taproot – one main root that goes deep
– Fibrous – many roots the same size
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Unusual adaptations (Venus flytrap)
Plant Life Cycles
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Germination – seeds that has its needs met and spouts
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Spread of Seeds (#34)
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Falling to the ground
Animals (eating & gathering)
Wind & water
Animals (unintentional carrying)
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Spores – tiny cells
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New plants from old
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Spider plants
Bulbs
Piece of a plant in water
Grafting
Tuber (swollen underground stems – potatoes)
Ecosystems (#31)
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Individual (single organism)
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Population (many individuals living in the same environment –
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Community (all populations living together)
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Ecosystem (a community and its physical environment)
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Habitat (a place where a population lives in the ecosystem) (#32)
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Niche (if many different populations share a habitat, each
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Environment determines the type of ecosystem (what plants)
Plants determine what animals live there
Amount of food affects the size of a population
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interdependent)
population has a certain role)
How Energy is Transferred in
an Ecosystem
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Producers – plants
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Consumers – animals
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Food Chain – how the consumers in an ecosystem are
connected by what they eat (#28 & #29)
– Herbivore – eat plants (1st level consumer)
– Carnivores – eat meat (2nd level consumers)
– Omnivore – eat plants & meat
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Decomposers – consumers that break down the tissues of
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Energy Pyramid – shows the amount of energy available to
dead organisms – uses what it needs and gives the rest back
to the soil– connect both ends of the food chain (#30)
pass from one level of a food chain to the next (10% of the
energy at any level is passed to the next higher level)
Ways in Which Organisms
Compete
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Competition – contest among organisms for resources
– Camouflage
– Animal’s speed
– Pack
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Share resources (trees)
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Symbiosis – a long-term relationship between different
organisms which may or may not benefit both organisms
– Mutualism – benefits both organisms (bees & flowers)
– Parasitism – one organism gains energy at the expense of
another (mistletoe)
Extinction and Its Causes
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Extinct – the last individual in the population dies
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Endangered – a population so small they are likely to
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Threatened – Are likely to become endangered if they
become extinct
are not protected
Mostly caused by human activity
 People have saved some organisms (banning DDT,
raising in captivity)
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Land Biomes
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Biome – large-scale ecosystem
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Climate Zone – region in which yearly patterns
of temperature, rainfall, and sunlight are similar
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Six types of biomes where climate zone and type
of soil determines the type of plants and animals
that live there: tropical rain forest, deciduous
forest, grassland, desert, taiga, and tundra
Types of Biomes
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Tropical Rain Forest (near equator)
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Deciduous Forest (all continent except Africa & Antarctica)
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Sunny and hot on a summer day; freezing on a winter night
Little water
Plant and animal adaptations
Taiga (Eurasia and North America)
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Not much rain
Lots of grass and not many trees
Major farmland; grazing livestock
Deserts
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Climate moderate
Trees lose their leaves in the fall
Lets enough light through the canopy to allow small trees and shrubs
Grasslands (on all continents except Antarctica)
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Climate warm and wet
Three layers of producers; diverse animals life
Most varied and complicated food webs
Evergreens because the winters are too long
Lower layer is a mat of pine needles
Diversity of animal life changes from season to season
Tundra (Greenland, most of N. Eurasia & N. America, southern tip of S. America & part of Antarctica)
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Low temperatures and long winters
No trees
Permafrost
No sun in the winter; always sunny in the summer
Water Ecosystems
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Saltwater (sunlight, nutrients, temperature, movement of
water)
– Intertidal Zone (tide and churning waves)
– Near Shore Zone (beyond the waves to 600 feet deep)
 Water is calm and temperature doesn’t change much
– Open-Ocean Zone (water is very deep)
 Most organisms live near the surface
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Freshwater (lakes, ponds, streams, rivers, some marshes, and
swamps)
– Water temperature and speed water moves determine plant and animal
life
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Estuaries (where a freshwater river empties into the ocean)
– Huge amounts of nutrients and organic matter
– High tide = salty water; Low tide = fresh water
– Calm and still; shallow; lots of sunlight
Natural Succession
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Succession – Gradual change in an ecosystem
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Primary Succession – occurs on bare, newly formed
land (volcanic islands, glaciers)
– Pioneer plants – 1st to invade a bare area
– Mossy stage – bits of organic matter and bird dropping create
nutrients
– Grassy stage – soil rich enough to support small trees
– Climate Community – deciduous forest; prairie; etc.
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Secondary Succession – return of a damaged
ecosystem (fire, volcanic eruption)
How People Change
Ecosystems
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Farming
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New Construction
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Cutting down forests
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Pollution
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Acid Rain
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Strip Mining (all topsoil and overlying rock layers
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Building on fragile ecosystems
removed)
Using Resources Wisely
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Conservation – protecting our resources
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Reduce
– Coal (main cause of acid rain)
– Appliances
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Reuse
– Limit disposable products
– Resale toys and clothes
– Buy used
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Recycle
– Aluminum
– Glass
– Paper
Restoring Ecosystems
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Rivers
– Reclamation (getting rid of PCBs)
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Wetlands
– Saltwater marshes, mangrove swamps and mud flats
– Provide natural water purifiers
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Your Backyard
– Replace grass with original ecosystem
– Limit pesticides and fertilizers