Middle School Science TAKS Review

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Middle School Science TAKS Review

• Objective 2
• Life Science

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Cell Theory

• The cell is the basic unit of all living things.
• All living things are made up of one or more
  cells.
• All living cells come from the reproduction of
  pre-existing cells.

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Cell Structures

• Cells have organelles to carry out cell
  functions.
• Cell membrane
• supports cell controls substances going in and
  out of the cell
• Cytoplasm
• jellylike fluid in cell
• Nucleus
• cell boss controls cell activities

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Animal Cell Diagramclick picture to study
structures
http//www.cellsalive.com/cells/cell_model.htm
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Plant Cell Diagramclick picture to study
structures
http//www.cellsalive.com/cells/cell_model.htm
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Cell Functions

• Homeostasis
• a cell must maintain stable internal conditions
  balance
• Osmosis
• movement of water through a selectively permeable
  membrane from a higher to lower concentration
• Diffusion
• random movement of molecules from a higher to
  lower concentration

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Cell Functions

• Turgor pressure
• pressure of water against a plant cell wall
• Mitosis
• division of the nucleus of a cell
• 1 parent cell creates 2 daughter cells

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How Cells Gain Release Energy

• All organisms use energy to carry out the
  functions of life.
• Photosynthesis
• plants use light to convert carbon dioxide and
  water into glucose and oxygen energy is stored
  in chemical bonds of glucose molecules
• Cellular Respiration
• cells break down glucose into usable energy the
  reverse of photosynthesis

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Can You Identify the Phases Mitosis?

• Interactive Mitosis

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Systems

• Tissue
• similar cells with specialized functions
• Organs
• two or more tissues performing a function
• Organ System
• group of organs working together to perform a
  specific function
• Organism
• any living thing

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Systems

• Feedback mechanism
• occurs when the body senses the results of its
  actions and adjusts what it is doing
• allows the body to maintain stable conditions

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Interactions of Human Systems

• Muscular, Skeletal, Nervous
• interact to move an arm
• Respiratory, Circulatory
• interact to take in oxygen and deliver it to
  cells throughout the body
• Digestive and Circulatory System
• interact to digest food and absorb and distribute
  nutrients

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Interactions of Human Systems

• Feedback mechanism
• endocrine system interacts with other systems to
  maintain the bodys equilibrium
• such as the level of glucose in blood

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Organ Systems of Human Body

• In the human body, 10 major organ systems each
  work to meet a specific need.
• Skeletal System - support structure, allow
  movement, produce red blood cells
• Muscular System - allows movement
  smooth,skeletal, and cardiac muscles
• Digestive System - digests and absorbs nutrients

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Organ Systems of Human Body

• Respiratory System - made up of lungs and other
  organs that allow us to obtain oxygen
• Circulatory System - the heart, veins, arteries
  and capillaries circulate blood through the body.
• Nervous System - the brain, sensory organs and
  nerves allow us to think, see, feet, and react to
  the environment around us.

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Organ Systems of the Human Body

• Endocrine System - produces hormones regulating
  growth, fluids, blood sugar, and energy levels.
• Excretory System - kidneys and bladder act as the
  bodys garbage collector to filter blood and
  excrete wastes and water.
• Integumentary System - the skin, hair and finger
  nails protect the body against infection and
  injury.
• Reproduction System - organs that allow humans to
  produce children.

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Heredity

• Inherited Trait - a trait an organism inherits
  from its parents,such as height or eye color.
• Gene - the part of a chromosome that governs a
  particular trait.
• Punnett Square - the diagram used to predict
  outcomes of genetic combinations.

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Heredity

• Dominant Trait - appears if it inherits the gene
  for that trait from either parent shown by
  capital letters on a Punnett Square.
• Recessive Trait - appears only if it inherits
  that trait from both parents shown by lower case
  letters on a Punnett Square.

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Punnett Square Review

• Punnett Square Review
• Interactive Punnett Squares

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Adaptation

• Genetic Mutation
• Change in gene caused by environmental damage or
  random error.
• Environmental Change
• When the environment changes,such as the climate
  becoming colder or dryer.
• Natural Selection
• Organisms with favorable hereditary traits are
  more likely to survive and reproduce than other
  organisms these organisms gradually increase
  their proportion of a species.

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Adaptation

• Species
• Group of similar organisms that can have children
  together.
• Population
• All the members of a species living in an area.

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Ecosystems

• An Ecosystem is a community of living organisms
  and their environment in a specific area.
• Nonliving Environmental Factors
• Influence an ecosystem, such as
  temperatures,sunlight, pH, and soil.
• Community
• All the organisms found in a single ecosystem.
• Population
• All of the organisms of the same species in a
  particular ecosystem.

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Ecosystems (click on map)

• Land Ecosystems
• Temperate forest
• Tropical rain forest
• Grassland
• Desert
• Tundra
• Water Ecosystem
• Oceans

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Flow of Resources in an Ecosystem

• Interaction of Organisms Predators,
  parasites,competition and cooperation.
• Recycling of Energy and Nutrients
• 1. Producers (plants) obtain energy from
  sunlight, water and nitrates from soil.
• 2. Consumers (animals) eat plants or other
  animals provided nitrates and CO2 to be used by
  plants.
• 3. Decomposers (bacteria, fungi) break down dead
  organisms into organic compounds.
• Ecological Succession Drastic events, like fire,
  bring a series of changes to an ecosystem.

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Ecosystems

• ?Animal Adaptations Website

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Succession

• Succession is the gradual and orderly process of
  change in an ecosystem brought about by the
  progressive replacement of one community by
  another until a stable climax is established.
• Succession occurs differently in different places
  around the world.

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Primary Succession

• The process of primary succession begins in a
  place without any soil.
• It starts with the arrival of living things
  called pioneer species - these are organisms that
  do not need soil to survive.
• Soil begins to form as the pioneer species and
  the forces of weather and erosion help break down
  rocks into smaller pieces.

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Primary Succession

• When the pioneer species die, they decay,adding
  small amounts of organic matter to the rock
  making soil.
• Plants such as mosses and ferns can grow in this
  new soil.
• Eventually, these plants die, adding more organic
  material. The soil layer thickens, and grasses,
  wildflowers, and other plants begin to take over.

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Primary Succession

• When these plants die, they add more nutrients to
  the soil.
• This buildup is enough to support the growth of
  shrubs and trees. All the while,insects, small
  birds, and mammals have begun to move in. What
  was once bare rock now supports all sorts of life.

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• http//www.micro.utexas.edu/courses/levin/bio304/e
  cosystems/succession.gif

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Secondary Succession

• Secondary succession is the changes which take
  place in a placed that has been disturbed or
  damaged.
• Volcanoes
• Forest fires
• Development
• Secondary succession is usually much quicker than
  primary succession.

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Secondary Succession

• http//www.countrysideinfo.co.uk/successn/second.h
  tm

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Succession

• http//www.kscience.co.uk/as/module5/succession/im
  ages/succession.jpg

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Succession

• Review the types of succession here
• http//library.thinkquest.org/17456/successionall.
  html
• http//www.pbs.org/americanfieldguide/teachers/for
  ests/forests_sum.html?