Transcript Life Sci MCAS Review

Mrs. McCarthy’s
MCAS Review
Life Science
th
6
Grade Curriculum
– Classification of Organisms
– Structure and Function of Cells
– Systems in Living Things
– Reproduction & Heredity
– Evolution & Biodiversity
– Living Things & Their Environment
– Energy & Living Things
– Changes in Ecosystems Over Time
Structure and Function of Cells
Cells are the basic units
of life.
All living things are made
of cells.
Cells are very small and
can only be seen with a
microscope.
Cells
• There are different types of cells:
– Animal Cells
– Plant Cells
• Some living things are multi-cellular
– Example: plant, animal
• Some living things are unicellular
– Example: bacteria, yeast
Parts of the Cell
Cell Wall-the outside of the cell
that strengthens the cell
membrane
Cell Membrane- keeps
cytoplasm in; allows nutrients
in & waste out
Chloroplasts-hold green
chlorophyll for photosynthesis
Vacuoles- store water & fluid
Nucleus- holds cell’s DNA
Cytoplasm-fluid in cell
Mitochondria- breakdown food
in the cell
Plant Cell
Plant Cells are
found in plants.
Unlike Animal
Cells, Plants
Cells contain:
Cell Wall &
Chloroplasts so
that they can
make food using
photosynthesis.
Animal Cell
Animal Cells are
found in
animals.
Unlike Plants
Cells, Animal
Cells do not
contain: Cell
Wall &
Chloroplasts.
Cellular Functions
• Cells function similar to living
organisms:
–Extracting Energy from Food
–Disposing of Waste
–Reproduction (Mitosis)
Heredity
• All living things have traits.
• Traits are stored in chromosomes.
• These are passed on from one
generation to the next in genes.
• Human cells contain about 30,000
different genes on 23 different
chromosomes.
• Punnett Squares show
possible inheritance.
Reproduction
There are 2 types of reproduction:
– Sexual: 2 Parent Cells Join Together to
Form a New Individual; Offspring Inherit
Half of Their Genes from each Parent
• Example: Plants & Animals
– Asexual: only 1 Parent Cell is Needed;
Parent Cell is Copied; Mitosis Occurs
• Example: Single-celled Organisms
Genes of DNA
Cells & Body
Tissues
Organs
Systems
Systems in Living Things
• The Human Body’s Major Systems:
– Digestion: Food Energy
– Respiration: Breathing
– Reproduction: Population
– Circulation: Blood Flow
– Excretion: Waste
– Immune: Protection from Disease
– Movement, Control, Coordination:
Moving, Thinking, Planning, Processing
Classification of Organisms
Classification is the arrangement of
organisms into orderly groups based on
their similarities.
Levels:
Hint:
King----Kingdom
Kingdom- large general group
Philip---Phylum
Phylum-
Came--Classes
ClassesOrdersFamilies-
Kingdom’s are
continuously
broken down
into classified
groups until
species
GenusSpecies- one kind
Over----Orders
For------Families
Grape--Genus
Soda---Species
Kingdoms
Plantae
Protista
•
All living organisms belong to one of the
kingdoms
• There are five Kingdoms:
1. Bacteria- E. coli,
2. Protista- single-celled organisms
3. Plantae- plants, flowers & trees Animalia
4. Fungi- fungus, mold & mushrooms
5. Animalia- animals, people, pets, bugs
Fungi
Bacteria
Evolution & Biodiversity
• Evolution: organisms adapt and change
over time
• Evidence: geology, fossils, comparative
anatomy
• Extinctions: many species have not been
able to adapt to habitat changes over time
Survival of the fittest
Living Things & Their
Environment
• Organisms interact with one another
and have different functions within an
ecosystem that enable the ecosystem
to survive.
• Circle of Life
• Food Web- Energy from food flows from
one organism to another
• Parts of the Food Web:
– Producers- use sunlight to make food
• Example: Plants
– Consumers-eat producers & organisms
• Example: animals
– Decomposers-break down remains of
dead organisms
• Example: bacteria & fungi
Decomposers & Nitrogen Cycle
• Decomposers- Living organisms break
down dead plants & animals (bacteria,
fungus)
• Nitrogen is produced in this cycle.
• Broken down material is used for compost
and has nutrients in it that contribute to the
system.
• Plants use energy from sunlight to make
sugars from carbon dioxide and water
through photosynthesis.
• This food can be used immediately, stored
for later use, or used by other organisms.
Photosynthesis
• The process where plants capture light energy
from the sun and change it into food.
Ecosystems
• Ecosystem- the habitat of living
organisms
• Land: Forests, Grasslands,
Deserts, Tundra
• Marine: Beaches, Seafloor, Reefs
• Freshwater: Moving Water, Still
Water, Wetlands
Changes in Ecosystems
Over Time
• Changes in the ecosystem can cause
extinction, habitat damage, & global warming.
• Ecosystems are effected by:
– Pollution
– Resource Depletion
– Alien Species
– Human Population Growth
– Habitat Destruction
Energy Resources
Energy Resources: Natural, Fossil Fuels, &
Alternatives
Natural Resources include wood, gasoline, wind
Fossil Fuels: nonrenewable energy resource
- Made over millions of years from buried
organisms
- Create environmental pollution problems
- Examples: coal, natural gas, petroleum
Alternatives: renewable & easy to replace resources
- Most are cleaner & safer.
- Examples: Solar, Wind, Hydroelectric, Biomass,
Nuclear (Dangerous)