A Walk Through 7th Grade Science

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A Walk Through 7th Grade Science
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Interactions of Living Things

• Abiotic vs. Biotic

BIOTIC Living factor. Animals, plants, bacteria.
ABIOTIC Nonliving factor. Light, water, heat,
rocks, energy, minerals.
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Interactions of Living Things

• Dichotomous Key
• An aid that is used to identify organisms based
  on the answers to a series of questions.

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Interactions of Living Things

• Ecosystem A community of living organisms and
  their interrelated physical and chemical
  environment.

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Interactions of Living Things

• Biological Diversity The variety and complexity
  of species present and interacting in an
  ecosystem and the relative abundance of each.
• BIOLOGICAL DIVERSITY IS A GOOD THING!

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Interactions of Living Things

• Niche The role played by an organism in an
  ecosystem its food preferences, requirements for
  shelter, special behaviors and interactions with
  other organisms in its habitat.

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Interactions of Living Things

• Trophic Levels

What happens to the amount of energy?

• Producer
• Herbivore
• Carnivore
• Consumer
• Omnivore

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Interactions of Living Things
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Interactions of Living Things

• Equilibrium The ability of an ecosystem to
  maintain stability among its biological
  resources.
• Homeostasis The tendency for a system to remain
  in a state of equilibrium by resisting change.

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Plants

• Photosynthesis Process by which plants, algae,
  and some bacteria use sunlight, carbon dioxide,
  and water to make food.

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Plants

• Chlorophyll A green pigment that captures light
  energy for photosynthesis.
• This is what makes plants green!
• Stomata Opening in a leaf that allows gas
  exchange.
• Transpiration The process by which plants
  release water vapor into the air.

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Cycles

• Carbon Cycle

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Cycles

• Water Cycle

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Cycles

• Succession The series of changes that occur in
  an ecosystem with the passing of time.

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Cells

• Cell The smallest unit that can perform all life
  processes.
• Cell Cycle The life cycle of a cell.

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Cells

• Cell Theory
• All living things are composed of cells
• Cells are the basic function and structure of
  life
• All cells come from other cells

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Cells

• Prokaryotic vs. Eukaryotic

No Nucleus!
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Cells

• Cell Processes
• Diffusion movement of particles from region of
  high density to low density
• Osmosis movement of water through a membrane
• Active Transport moving substances across cell
  membrane (requires ENERGY from cell)
• Passive Transport moving substances across cell
  membrane (no energy required)
• Enzymes protein that speeds up a chemical
  reaction

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Mitosis and Meiosis
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Cells

• In case you thought cells were boring
• http//www.youtube.com/watch?v-zafJKbMPA8
• What are the two different types of cells?
• Plant and Animal
• What are the components of cells called?
• Organelles
• Which organelle controls the cell?
• Nucleus

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Levels of Organization
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Types of Reproduction
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Guess the Type of Reproduction
Cloning
Mitotic Cell Division
Regeneration
Vegetative Reproduction
Budding
Fission
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Structure Function
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Heredity

• Dominant Trait - CAPITAL LETTERS
• Recessive Trait lower case letters
• Co-Dominance mixture of both
• Example
• In purple people eaters, one-horn is dominant and
  no horns is recessive.
• One-horn H
• No horns h

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Heredity

1. How creepy is this?
2. What are the two possible genotypes for this
   people eater (he has one horn).

• Homozygous Same allele
• Heterozygous Different alleles
• Example
• In purple people eaters, one-horn is dominant and
  no horns is recessive.
• Homozygous HH or hh
• Heterozygous Hh

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Heredity Brain Pop!
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Quiz Yourself!
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Quiz Yourself!
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Quiz Yourself!
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Quiz Yourself!
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Practice a Punnett Square

• One flower is heterozygous red (Rr) and it is
  crossed with a homozygous white (rr) plant. Use a
  Punnett square to determine the probability of
  one of their offspring having a red color.

R
r
r
Rr
rr
50 Rr ? Red 50 rr ? White
r
Rr
rr
Genotype vs. Phenotype
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Genetics - Pedigrees
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Genetics

• Mutation a change in a gene.

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Evolution

• Adaptation A characteristic that improves an
  individuals ability to survive and reproduce in
  a particular environment.

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Evolution

• Evolution The process in which inherited
  characteristics within a population change over
  generations such that new species sometimes arise.

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Natural Selection

• The process by which individuals that are better
  adapted to their environment survive and
  reproduce more successfully than less adapted
  individuals do.