Diversity in the Living World Biol 1403

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Diversity in the Living World Biol 1403

• What is biology?
• The science or study of life.
• What is life?
• A way of capturing and using energy and raw
  materials

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Characteristics of Life

• A way of sensing and responding to the
  environment
• A capacity to reproduce
• Its an evolving process, this means that the
  traits characterizing individuals in a population
  can change from one generation to the next

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More about Living Organisms

• There will be many examples that we will come
  across in this course that will explain how
  organisms are
• Constructed
• Function
• Able to live in an environment
• Able to do certain tasks

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Concepts

• Throughout these lectures I will provide an
  overview of basic biological concepts.
• Unity underlies the world of life
• All organisms are alike in key aspects
• Ex kidneys
• Ex reproduction

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Concepts

• - they all consist of one or more cells made of
  the same kind of substances and put together
  involving the same basic principles.
• - they require energy for their activities
  which they obtain from their surroundings
• - all organisms sense and respond to the
  changing conditions of their environment

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Variety

• - they all have the capacity to grow and
  reproduce, based on instructions contained in DNA
• There is tremendous variety in the life forms
  that we see around us
• - millions of different kinds (species) of
  organisms

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Variety

• DNA Helix

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Variety

• Who knows how many more species of organisms
  there may have been at the earliest stages of
  life on earth, each with their own unique
  characteristics (traits)
• Charles Darwin, a 19th century naturalist,
  developed theories of evolution which helped to
  explain the diversity that exists among
  organisms, especially his theory of evolution by
  natural selection

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Variety

• Darwin

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Darwin and Evolution

• Darwins theories attempted to coalesce various
  disciplines of biology.
• Like other branches of science, biology depends
  on observations, hypotheses, predictions, and
  observational and experimental tests
• To test these scientific theories, it is
  necessary to get out among the various organisms
  and study them carefully

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Variety

• Scientific Method Flowchart
• Define/Identify the Problem
• Form a Hypothesis
• Make Observations or Test Hypothesis and Perform
  Experiments
• Organize and Analyze Data
• Do Experiments and Observations Support
  Hypothesis?
• If No, Perform New Experiments and Repeat Step 4
• Draw Conclusions
• Communicate Results

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DNA, Energy and Life

• A book
• A car
• A computer
• A jellyfish
• A dog
• A whale
• What do these items have in common?

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Molecular Make-Up

• They are all made of atoms
• - atoms have protons, electrons, and neutrons
  as building blocks.
• What do living things have (i.e., building
  blocks) that provide the organism the potential
  for life?

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Variety

• Sodium atom

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Essential Molecules

• Some building blocks
• - nucleic acids
• - proteins
• - carbohydrates
• - lipids
• In nature, only cells build these molecules

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Building Blocks

• DNA RNA

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Building Blocks

• Proteins Lipids

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Building Blocks

• Carbohydrate

           
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DNA

• What is the smallest unit that has the capacity
  for life?
• - It is the nucleic acid called, DNA,
• deoxyribonucleic acid
• DNA has the instructions for assembling a variety
  of proteins from smaller molecules known as Amino
  acids.

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DNA

• Helical Structure

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Products of DNA

• A particularly important type of protein made by
  DNA is the Enzyme.
• - Enzymes can give energy to a chemical
  reaction, build, split and rearrange molecules of
  life.
• - Some enzymes are involved with nucleic acids
  such as, RNA (ribonucleic acid) which then take
  the message they receive from DNA to make proteins

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From DNA to Protein

• The basic pathway would look like this
• DNA ? RNA ? Protein

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DNA and Inheritance

• All cells contain this nucleic acid and as the
  cell divides, the molecule (DNA) is replicated in
  the new cells.
• New cells and multi-celled organisms inherit
  their defining traits from their parents.

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The Bottom Line
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Inheritance

• This is the acquisition of traits through the
  transmission of DNA from the parents to the
  offspring.
• The term, reproduction, is used for the actual
  mechanisms of transmitting DNA to offspring.

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DNA is the Key

• DNA also guides development.
• In a multi-celled organism, tissues and organs
  are specialized to perform specific functions.
• Consequently, the DNA contained in these cells
  is programmed to transcribe a set of instructions
  to another nucleic acid, mRNA.

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DNA is just the start

• This molecule carries the genetic message from
  DNA to outside the nucleus.
• The mRNA then attaches to a ribosome
• It is at the site of the ribosome where
  proteins are assembled.

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Roles for Proteins

• Proteins are required by an organism
• for specific functions
• Transporting molecules out of the cell
• Repairing membranes
• Building additional tissues
• And much more.

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Protein involvement

• Proteins needed for overall development
• Insect development and growth
• Moth metamorphosis
• - Egg, larva, pupa, and adult

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Metamorphosis

• Cicada moulting

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Cellular building blocks

•   

                                 
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Connections

• Amino acid to Protein

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How things get done.

• Energy
• - Besides needing DNA, cells need Energy to
  survive.
• - This work is seen at the level of the atom
• - Atoms either give up, share or accept
  electrons

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ATP?

• This process or activity occurs during the
  phase of molecular synthesis, catabolism or
  rearrangement.
• Energy is needed to make these things happen.
  In biological systems, energy will be provided in
  the form of ATP, adenosine triphosphate.

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Further Defining Life

• Metabolism
• This is another characteristic of whether
  something can be considered as living.
• - all the controlled enzyme-mediated chemical
  reactions by which cells acquire and use energy
  to synthesize, store, degrade and eliminate
  substances in ways that contribute to growth,
  survival and reproduction.

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Metabolism

• Every living cell has the capacity to
• Obtain and convert energy from its surroundings
• To use energy to maintain itself, grow and
  produce more cells

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A Metabolic Process

• An example of metabolism might be
• - Photosynthesis
• - - sunlight is converted into
  chemical energy, in the form of ATP
  molecules
• light
• 12H2O 6CO2 ? ? 6O2 C6H12O6 6H20
• energy

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Photosynthesis

• 6 Oxygens
• 1 Sugar
• 6 Waters

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Plant Metabolism

• We will discuss later how the plant captures the
  sunlight energy and converts it into chemical
  energy in the form of glucose, water and energy.

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Plants
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Metabolism

• ATP is involved in helping hundreds of metabolic
  events proceed by transferring energy to reaction
  sites where it affects enzymes in a way that
  enables them to synthesize or breakdown molecules
  that can be used by the organism.

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Aerobic Respiration

• This is a process that can release energy that
  cells stored earlier in the form of starch and
  other kinds of molecules.

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Respiration

• Krebs Cycle

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Characteristics of Life

• Living things are made of cells.
• Living things obtain and use energy.
• Living things grow and develop.
• Living things reproduce.
• Living things respond to their environment.
• Living things adapt to their environment

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Characteristics of Life

• A Stimulus is a specific form of energy that a
  receptor can detect.
• EX sunlight energy
• heat energy
• binding energy
• mechanical energy

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Characteristics of Life

• Cells adjust metabolic activities in response to
  signals from receptors
• EX glucose and diabetes (receptors)
• Organisms respond nicely to energy changes so
  that their internal operating conditions usually
  remain within tolerable limits

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Homeostatis

• Cell

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Characteristics of Life

• This state in which physical and chemical aspects
  of the internal environment are being maintained
  within ranges suitable for a cells activities is
  called, Homeostasis

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Biological Organization

• A cell is the smallest organizational unit having
  a capacity to survive and reproduce on its own,
  given DNA instructions, building blocks, energy
  inputs and other suitable conditions.
• EX Amoeba

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Single Cell Animal

• Amoeba

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Biological Organization

• Multi-cellular organisms consisting of
  specialized interdependent cells, typically are
  organized in tissues and organs.
• Though even isolated human cells remain alive
  under controlled conditions in the laboratory
  (cell cultures)

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Biological Organization

• Cells and multi-celled organisms are usually a
  part of a Population a group of organisms of the
  same kind.
• EX Zebra Hela cells

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Biological Organization

• All populations of all species living in the
  same area, live in a community.
• EX trees bacteria zebras
• Refer to page 6 in the text

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Interdependence

• Animals that directly or indirectly obtain
  their food energy stored in tissues of producers
  are known as, Heterotrophs.
• They are also known as, Consumers.

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Interdependence

• A great flow of energy from the sun into the
  world of life starts with Producers.
• Plants and other organisms that make their own
  food are known as Autotrophs
• EX

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Interdependence

• Then there are a class of organisms that will
  breakdown sugars and other organic and biological
  molecules to simpler materials, some of which are
  re-cycled back to the producers. These organisms
  are known as, Decomposers.
• EX

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Interdependence

• Organisms connect with one another via one-way
  flow of energy through them a cycling of
  materials among them (Fig. 1.6 pg. 7)
• Their interconnectedness affects the structure,
  size, and composition of population
  communities. It can affect ecosystems and even
  the biosphere.
• Think of Food shortages
• Cholera epidemics
• Acid rain global warming

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Bacterial Diseases

• Cholera

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Summary

• Characteristics that all living things have in
  common.
• They stay alive by way of
• - metabolism
• - ongoing energy transfers at cell level
• - sense and response to environment
• - have capacity to reproduce pass on traits

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Diversity

• Living organisms have one other feature in
  common, a vast amount of diversity.
• There are millions of kinds (species) of
  organisms.

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Classification

• With so many species a method is needed to
  distinguish the different varieties of sponges,
  horses, fishes etc.
• Carolus Linneaus designed a classification
  scheme using a two-part name to identify species.

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Classification

• KINGDOM
• PHYLUM
• CLASS
• ORDER
• FAMILY
• GENUS
• SPECIES

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Classification

• The first part designates the Genus.
• The genus encompasses all of the species that
  are closely related because of their form,
  function, and ancestry.
• The second part of the name designates a
  particular species within a genus.

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Classification

• EX The Lone Star Tick
• Amblyomma americanum

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Classification

• EX The American Cockroach
• Periplaneta americanum

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Classification

• Biologists group species that are related by
  descent from a common ancestor.
• Scholars once recognized only 2 groups,
• Animals
• Plants

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Classification

• Now, most biologists favor a three-domain system
  of classification.
• Bacteria Archaea Eukarya
• There are 6 groups within these domains

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Classification

• These groups are known as Kingdoms
• Archaebacteria Eubacteria
• Protistans Fungi
• Animals Plants

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Classification

• Archaebacteria single-celled prokaryotes that
  are found in hot springs, salt lakes other
  harsh environments.

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Classification

• Eubacteria true bacteria are more common and
  widespread than Archaebacteria
• SEM SEM
• Enterococcus Pseudomonas

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Classification

• Protistans - widely ranging microbes, including
  slime molds, protozoa and primitive algae.
  Eukaryotic
• Amoeba Pfiesteria

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Classification

• Animals - multicellular, while most Protista
  (excepting the multicellular algae, which are
  plant-like) are unicellular. Heterotrophism
  separates the animals and fungi from plants, and
  the lack of cell walls in animal cells makes them
  distinct from fungi. Animals possess several
  other unique features. These include interior
  digestion of food, a digestive tract where
  enzymes are secreted digestion occurs.

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Classification

• Animals can be very diverse.
• EX herbivores
• carnivores
• parasites
• scavengers

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Classification

• Fungi eukaryotic, heterotrophic and
  saprophytic. Composed of filaments called
  hyphae and contain chitin in their cell walls.

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Classification

• Plants - composed of multicellular, autotrophic
  organisms. Photosynthesize to fix inorganic
  carbon into organic molecules. Plants are primary
  autotrophs

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Diversity

• How can we have so many different kinds of
  organisms with many looking very similar?
• One source of variation is the Mutation.

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Diversity

• DNA works to
• Ensure its instructions produce offspring
  resemble its parents
• While permitting variations in the details of
  most traits

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Diversity

• Some changes or variations in traits are neither
  desirable or advantageous.
• These changes, mutations, may affect the
  individual at the genetic level, genotype, or at
  the physical level, phenotype.

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Diversity

• These mutations may be harmful and affect the
  bodys,
• Growth, Development, or Function
• Some mutations may be harmless or beneficial.

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Diversity

• A beneficial mutation can be seen in the UK
  coal-burning factories example.
• Dark-colored moths v. light-colored moths
• Also an example of Natural Selection

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Natural Selection

• An evolutionary mechanism that occurs when
  some individuals of a population are better able
  to adapt to their environment and, subsequently,
  produce more offspring. Nature, in effect,
  selects which members of a population are fit to
  survive long enough to reproduce. Differential
  productive success between individuals is the
  key. Those who produce more offspring have a
  greater influence on the gene frequencies of the
  next generation. This mechanism of evolutionary
  change was first articulated by Charles Darwin.