LIFE SCIENCE

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LIFE SCIENCE

• What You Need to Know

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Explain that cells are the basic units of
structure and function of living organisms, that
once life originated all cells come from
pre-existing cells, and that there are a variety
of cell types.

• Explain that living cells a. are composed of a
  small number of key chemical elements (C, H, O,
  N, P, and S) b. are the basic unit of structure
  and function of all living things c. come from
  pre-existing cells after life originated and d.
  are different from viruses.
• Compare the structure, function, and
  interrelatedness of cell organelles in eukaryotic
  cells (e.g. nucleus, chromosome, mitochondria,
  cell membrane, cell wall, chloroplast, cilia,
  flagella) and prokaryotic cells.

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Cell Theory

• Cells come only from other cells. The old theory
  was called spontaneous generation and was
  disproved by Redi.
• Cell theory began with the invention of the
  microscope by van Leeuwenhoek in the 1600s. Hooke
  called the building blocks of living things
  cells.
• There are two basic cell types prokaryotes and
  eukaryotes that contain membrane-bound
  organelles.
• Viruses are not living and have only nucleic
  acids in a protein coat. They can only
  reproduce inside a living cell.

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Cell Organelles

• Only eukaryotic cells have these
• a. nucleus directs all cell functions
• b. nucleolus makes ribosomes
• c. cell wall found only in plant cells, hold
  cell together
• d. ribosomes make proteins following DNA
  directions
• e. cytoplasm clear gel inside the cell
• f. endoplasmic reticulum site of cellular
  chemical reactions
• h. Golgi apparatus sorts and holds proteins
  until needed
• i. vacuoles temporary storage of materials
• j. lysosomes contain digestive enzymes
• k. mitochondria transform energy for the cell
• l. chloroplasts capture light energy and
  convert to chemical
• m. centrioles help with cell division
• n. cilia and/or flagella help cell move, if
  there at all

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Pictures of Cell Types
All cells fall into one of the two major
classifications of prokaryotes and eukaryotes.
Prokaryotes were here first and for billions of
years were the only form of life. Eukaryotes are
more organized and appeared later. There are some
of both on Earth today.
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Explain the characteristics of life as indicated
by cellular processes and describe the process of
cell division and development.

• Explain the characteristics of life as indicated
  by cellular processes including a. homeostasis
  b. energy transfers and transformations c.
  transportation of molecules d. disposal of
  wastes and e. synthesis of new molecules.
• Summarize the general processes of cell division
  and differentiation, and explain why specialized
  cells are useful to organisms and explain that
  complex multi-cellular organisms are formed as
  highly organized arrangements of differentiated
  cells.

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Cellular Processes

• There are many cellular processes. We will focus
  on
• a. homeostasis regulation of internal
  environment to help guarantee survival
• b. energy transfers and transformations making
  food from light, extracting energy from food
  (respiration, photosynthesis, fermentation,
  digestion)
• c. transportation of molecules supply cells
  with nutrients
• d. disposal of wastes removal from cells or
  organisms
• e. synthesis of new molecules proteins made in
  ribosomes, following instructions from DNA

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Cell Division

• There are two types of cell division
• a. Meiosis Meiosis is the process that
  shuffles the genes around. Plants do it, animals
  do it, and even fungi do it (sometimes). Instead
  of creating two new cells with equal numbers of
  chromosomes (like mitosis), the cell does a
  second division soon after the first. That second
  division divides the number of chromosomes in
  half. This is sexual reproduction.
• b. Mitosis - The big idea to remember is that
  mitosis is the simple duplication of a cell and
  all of its parts. It duplicates its DNA and the
  two new cells (daughter cells) have the same
  pieces and genetic code. Two identical copies
  come from one original. Start with one get two
  that are the same. This is asexual reproduction.
• Both types of cell division are very important.

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Explain the genetic mechanisms and molecular
basis of inheritance.

• Illustrate the relationship of the structure and
  function of DNA to protein synthesis and the
  characteristics of an organism.
• Explain that a unit of hereditary information is
  called a gene and genes may occur in different
  forms called alleles (e.g., gene for pea plant
  height has two alleles, tall and short).
• Describe that spontaneous changes in DNA are
  mutations which may or may not be passed on to
  future generations.
• Use the concepts of genetics to explain
  inheritance.

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Hereditary Information

• Mendel was one of the first geneticists, working
  with pea plants.
• Chromosomes are made of genes and genes can be of
  different types, called alleles. Alleles
  determine traits.
• Genes can be dominant or recessive or neither.
• Some traits are determined by more than one gene.
  Some diseases are genetically determined, like
  cystic fibrosis, etc.
• Genotype is your genetic code phenotype is the
  outward appearance of those genes or the trait
  itself.
• Homozygous is when an organism possesses 2
  identical genes for a trait heterozygous is one
  of each gene. (TT or Tt).
• Sex-linked traits, such as red-green color
  blindness and hemophilia, are carried on the sex
  chromosomes (X and Y in humans).

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Mutations

• Mutations are changes in DNA sequence. They can
  be caused by errors in replication,
  transcription, cell division, or external agents
  (such as radiation, chemicals, and even high
  temperatures).
• Mutations are especially significant if passed
  from one generation to another.
• Mutations, by effecting the DNA sequence, can
  also affect the ability to make important
  proteins.
• It is difficult, or impossible, to repair damaged
  DNA.

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Tracing Inherited Traits

• Punnett squares are often used.
• Pedigrees can also be used.

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Explain the flow of energy and the cycling of
matter through biological and ecological systems
(cellular, organismal, and ecological).

• Describe how matter cycles and energy flows in
  living systems and between living systems.
• Describe how cells and organisms acquire and
  release energy.
• Explain that living organisms use matter and
  energy to synthesize a variety of organic
  molecules and to drive life processes.

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Energy and Food Webs

• As predators eat prey and consumers eat
  producers, energy is transferred from one
  organism to another.
• What happens when the chain is disrupted? For
  instance, all the snakes are killed by a disease.
  How does this affect the other living things?

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Explain how evolutionary relationships contribute
to an understanding of the unity and diversity of
life.

• Describe that biological classification
  represents how organisms are related with species
  being the most fundamental unit.
• Explain that variation of organisms within a
  species increases the likelihood that at least
  some members of a species will survive under
  changing conditions.
• Relate diversity and adaptation to structures and
  their functions in living organisms.

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Classification

• There are 6 Kingdoms Eubacteria, Archaebacteria,
  Protists, Fungi, Plants, and Animals.
• Each Kingdom is then broken down into phylum,
  class, order, family, genus, and species. Animals
  in a species are the MOST related to each other.
• Scientific names use the genus and species names
  (Genus species). Canis rufus is a red wolf, Canis
  latrans is a coyote, and Canis lupus is a grey
  wolf. They are different species because of
  physical traits. Usually one species cannot breed
  with other species and produce fertile offspring.

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Survival of the Fittest

• Genetic changes can be caused by mutation,
  genetic drift, and gene flow.
• Some genes protect organisms from one thing but
  endanger them in other ways. Presence of sickle
  cell anemia gene protects people from malaria.
  Where the person lives may determine which is
  better.

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Explain the structure and function of ecosystems
and relate how ecosystems change over time.

• Explain how living things interact with biotic
  and abiotic components of the environment.
• Relate how distribution and abundance of
  organisms and populations in ecosystems are
  limited by the ability of the ecosystem to
  recycle materials and the availability of matter,
  space and energy.
• Conclude that ecosystems tend to have cyclic
  fluctuations around a state of equilibrium that
  can change when climate changes, when new species
  appear as a result of immigration or when species
  disappear.

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Ecosystems

• Ecosystems vary in size. They can be as small as
  a puddle or as large as the Earth itself. Any
  group of living and nonliving things interacting
  with each other can be considered as an
  ecosystem.
• Within each ecosystem, there are habitats which
  may also vary in size. A habitat is the place
  where a population lives. A population is a group
  of living organisms of the same kind living in
  the same place at the same time. All of the
  populations interact and form a community. The
  community of living things interacts with the
  non-living world around it to form the ecosystem.
  The habitat must supply the needs of organisms,
  such as food, water, temperature, oxygen, and
  minerals. If the population's needs are not met,
  it will move to a better habitat. The processes
  of competition, predation, cooperation, and
  symbiosis occur.
• Biomes are ecosystems where several habitats
  intersect.

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Describe how human activities can impact the
status of natural systems.

• Describe ways that human activities can
  deliberately or inadvertently alter the
  equilibrium in ecosystems. Explain how changes in
  technology and biotechnology can cause these same
  kinds of changes.
• Illustrate how uses of resources at local, state,
  regional, national, and global levels have
  affected the quality of life.

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Describe a foundation of biological evolution as
the change in gene frequency of a population over
time. Explain current and historical
developments. Describe how scientists continue to
investigate and analyze aspects of evolutionary
theory.

• Recognize that a change in gene frequency is a
  foundation for evolution.
• Explain about natural selection.
• Describe some historical developments that
  occurred in evolutionary thought.
• Describe how scientists continue to investigate
  and analyze aspects of evolutionary theory.

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Evolutionary Thoughts

• Things change. The process of cars changing over
  the past 100 years can be thought of as an
  evolution in engineering. When an organism
  changes over many generations, it might be better
  suited to live, or more likely to die.
• If the change was that you are a 500-pound bird
  with little tiny wings and little tiny legs,
  chances are you wouldn't move around too well.
  One day you might run out of food and die or be
  eaten.
• Mutations, genetic drift, and migration may help
  this process of evolution.
• Fossil evidence shows changes in organisms over
  time.

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Convergent Evolution

• CONVERGENT EVOLUTION This is when two totally
  different species develop similar traits. Outside
  natural factors create a situation where that
  skill is a benefit. For example, you are a plant
  and I am an animal. We both have animals hunting
  us and eating us. We need protection. So we both
  develop spines to poke the hunters. The spines
  are made in different ways but do the same job.
  You are a cactus and I am a porcupine.

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Divergent Evolution

• DIVERGENT EVOLUTION We start as the same
  species, but then as more generations develop, my
  group becomes good at one thing and yours at
  another. Bird beaks are a good example for this
  one. One species of bird can develop in different
  directions depending on what type of food it
  eats. Their beaks develop different shapes after
  many generations. Charles Darwin used bird
  development in many of his scientific papers.

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Explain how natural selection and other
evolutionary mechanisms account for the unity and
diversity of past and present life forms.

• Analyze how evolutionary mechanisms provide a
  scientific explanation for the diversity and
  unity of past and present life forms.
• Explain that life on Earth is thought to have
  begun about 4 billion years ago. During most of
  the history of Earth, only single celled
  organisms existed but once cells with nuclei
  developed, increasingly complex organisms evolved.

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Summarize the historical development of
scientific theories and ideas, and describe
emerging issues in the study of life sciences.

• Use historical examples to explain how new ideas
  are limited by the context in which they are
  conceived.
• Describe advances in life sciences that have
  important long-lasting effects on science and
  society.
• Analyze and investigate emerging scientific
  issues, such as genetically modified food, stem
  cell research, and cloning.

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Biotechnology

• Some examples of biotechnology are
• a. imaging (X-rays, scans, etc)
• b. genetic engineering
• c. genome projects
• d. newer and better microscopes
• e. stem cell research
• f. cloning
• g. genetically modified foods.