Lesson 1.2 Flashcards
proposed that living
things may develop spontaneously from nonliving matter
and that this process frequently occurs in nature.
SPONTANEOUS GENERATION THEORY
The concept of spontaneous theory was first put forth by the
Greek philosopher
Aristotle (384–322 BC)
pneuma
vital heat
states
that life originates from pre-existing life
biogenesis
conducted an experiment that
challenged the idea of spontaneous generation
Italian physician Francesco Redi 1668
challenged Redi’s experiment.
English priest John Needham 1745
challenged Needham’s experiment
Italian scientist Lazzaro Spallanzani 1767
experiment that most scientists were convinced
that spontaneous generations does not occur
Louis Pasteur 1861
The oldest hypothesis that life came from a divine being is the
most widely accepted belief. Creationist believe that everything was made by supreme being
in a six-day period.
DIVINE CREATION
proposes that a meteor or cosmic dust may
have carried to Earth significant amounts of organic
molecules, which started the evolution of life
Panspermia
All organisms share common characteristics that guide
in defining what one means by life. There are 5 unifying themes:
Organization
Information
Energy and Matter
Interactions
Evolution
Theme 1
New Properties Emerge At Successive Levels Of
Biological Organization
Even from space, we can see signs of Earth’s life-In the green mosaic of the forests, for example. We can also see the entire biosphere, which consists of all life on Earth and all the places where life exists: most regions of land, most bodies of water, the atmosphere to an altitude of several kilometers, and even sediments far below the ocean floor.
The Blosphere
Our first scale change brings us to a North American mountain meadow, which is an example of an ecosystem, as are tropical forests, grasslands, deserts, and coral reefs. An ecosystem consists of all the living things in a particular area, along with all the nonliving components of the environment with which life Interacts, such as soll, water, atmospheric gases, and light.
Ecosystems
The array of organisms inhabiting a particular ecosystem is called a biological _______. The _______ in our meadow ecosystem includes many kinds of plants, various animals, mushrooms and other fungi, and enormous numbers of diverse microorganisms, such as bacteria, that are too small to see without a microscope. Each of these forms of life belongs to a species-a group whose members can only reproduce with other members of the group.
Communities
A ________ consists of all the Individuals of a species living within the bounds of a specified area. For example, our meadow includes a _______ of lupine (some of which are shown here) and a population of
mule deer. A community is therefore the set of ______ that inhabit a particular area.
Populations
Individual living things are called _____ . Each plant in the meadow is an ______ ,
and so is each animal, fungus, and bacterium.
Organisms
The structural hierarchy of life continues to unfold as we explore the architecture of a complex organism. A leaf is an example of an organ, a body part that is made up of multiple tissues and has specific functions in the body. Leaves, stems, and roots are the major organs of plants. Within an organ, each tissue has a distinct arrangement and contributes particular properties to organ function.
Organs
Viewing the tissues of a leaf requires a microscope. Each _____ is a group of cells that work together, performing a specialized function. The leaf shown here has been cut on an angle. The honeycombed tissue in the interior of the leaf (left side of photo) is the main location of photosynthesis, the process that converts light energy to the chemical energy of sugar. The Jigsaw puzzle-like “skin” on the surface of the leaf is a tissue called epidermis (right side of photo). The pores through the epidermis allow entry of the gas CO2, a raw material for sugar production.
Tissues
is life’s fundamental unit of structure and function. Some organisms consist of a single cell, which performs all the functions of life.
Cells
Chloroplasts are examples of ______, the various functional components present in cells. The Image below, taken by a powerful microscope, shows a single chloroplast.
Organelles
Our last scale change drops us into a chloroplast for a view of life at the _____ level. A _____ is a chemical structure consisting of two or more units called atoms, represented as balls in this computer graphic of a chlorophyll molecule.
Molecules
Theme 2
Life’s Processes Involve the Expression and
Transmission of Genetic Information
The transmission of traits from one generation to the next
Heredity
