Download Lesson 1A - Living Things

INTRODUCTION
Science 3001
Science II: Earth & Life Sciences I
Mr. Kishore Lal
Living Things
Lesson 1A
Introduction - Living Things
Lay People
How do lay people define living?
What do they mean by dead?
Can you tell the difference between living and dead?
Is there a difference between dead and non-living?
Can you tell the difference between living and non-living?
Scientists
How do scientists define living?
What do they mean by dead?
How do they tell the difference between living and dead?
How do they classify as living or non-living?
What are some significant differences between how science and
lay people define living thing?
Living Things
Living things
• are made of cells.
• obtain and use energy (respiration).
• obtain and use nutrients (nutrition).
• grow and develop (growth).
• reproduce (reproduction).
• respond to their environment (sensitivity).
• produce and eliminate waste products that may be toxic
(excretion)
• sometimes are able move from one place to another
(locomotion)
• adapt to their environment.
Living Things
• A single individual or even a group of living things may not
show all of the above characteristics.
• Something may follow one or just a few of the characteristics
listed above and is still not necessarily living.
• To be considered alive, an individual object or the group it
belongs to must exhibit most of the characteristics of living
things.
Answer this question - Are the following living?
• Crystals growing on the bottom of a saturated solution.
• A car breathing in air (oxygen) and burning fuel to move.
• Using a fuel like coal in a stove to produce energy.
• A motion sensor turning on lights.
• Waste products being eliminated into the environment by an
industrial plant.
Nature vs Behaviour of Things
It is clear that behaviour of living things can be mimicked by non
living things
• As technology increases, it is becoming increasingly difficult
to tell living from non-living in this modern world.
• One way to do so is to look at the nature of living things how they are built.
• Cells can b e seen as "the building blocks of life".
• Life, from the simple like bacteria to the complex like human
beings, are made up of cells.
• However, despite their apparent differences, the major groups
represented by plants and animals are made up of cells that
actually possess many of the same structures.
Cells
Cells
Plant and animal cells have:
• Nucleus: the cell's 'command center'. It regulates the various
metabolic processes within the cell and contains most of the
cell's genetic material (DNA), is usually located near the center
of animal cells, and closer to the edge in plants.
• Cell Membranes: This layer surrounds and protects the
contents of the cell. It allows certain molecules to pass through
it and enter the cell, while preventing others from so doing
(selectively permeable).
• Cytoplasm: The fluid which inside the cell. Organelles are
suspended in the cytoplasm.
Cells
Plant and animal cells have:
• Mitochondria: the ‘powerplant' of the cell. It converts food into
energy. The number of mitochondria is an indicator of the
activity level of the cell. So plant cells tend to have fewer
mitochondria than animal cells. Mitochondria also contain a
small amount of DNA, and therefore play a role in genetics.
• Golgi Bodies: location where substances are processed and
carried to the proper location within the cell, or out of the cell
altogether.
Cells
Plant and animal cells have:
• Vacuoles: These are sacs which serve as storage units.
Vacuoles in animal cells are tiny, and are used to carry
substances out of the cell, or to engulf undesirable substances
such as bacteria or bits of dead tissue. In plant cells, there are
usually only one large vacuole which acts as a storage tank for
food, water, waste products and other materials.
Primary Differences Between Plant and
Animal Cells
Plant cells:
• Produce their own food in the chloroplasts by a process called
photosynthesis to use the energy of sunlight to convert carbon
dioxide and water into food. The chloroplasts contain
chlorophyll that gives many plants their green colour.
• Have a rigid cell wall which helps support their weight. Many
animals usually do this by means of a skeleton.
• Have a cell wall on the outside of the cell membrane, which
together with the central vacuole helps the cell maintain shape
and rigidity.
• Have a large central vacuole, which when filled with water helps
to keep the cell rigid because of the water pressure against the
cell wall . As vacuoles loose water a plant wilts.
Primary Differences Between Plant and
Animal Cells
PRESENT
ORGANELLE
DESCRIPTION
FUNCTION
IN
outer layer
support (grow tall)
rigid, strong,
protection
cell wall
plant
stiff
allows H2O, O2,
made of
CO2 to pass into
cellulose
and out of cell
Primary Differences Between Plant and
Animal Cells
PRESENT
ORGANELLE
DESCRIPTION
IN
cell
membrane
plant animal
plant - inside
cell wall
animal - outer
layer
FUNCTION
selectively
permeable controls
movement of
materials in/out
of cell
support
protectionbarrier between
cell and its
environment
Primary Differences Between Plant and
Animal Cells
PRESENT
ORGANELLE
DESCRIPTION
IN
nucleus
plant animal large, oval
FUNCTION
controls cell
activities
clear, thick,
jellylike
supports
material and
cytoplasm
plant animal
/protects cell
organelles found
organelles
inside cell
membrane
bean-shaped
breaks down sugar
mitochondrion plant animal with inner
molecules to
membranes
release energy
Primary Differences Between Plant and
Animal Cells
PRESENT
ORGANELLE
DESCRIPTION
IN
stacks of
flattened
Golgi Bodies plant animal
membranous
sacs
vacuole
fluid-filled
plant animal
cavities
FUNCTION
substances are
processed and
carried to the
proper location
within the cell, or
out of the cell
altogether
store food, water,
waste (plants need
to store large
amounts of food)
Primary Differences Between Plant and
Animal Cells
PRESENT
ORGANELLE
DESCRIPTION
FUNCTION
IN
green, oval
uses energy from
usually
sun and water and
chloroplast plant
containing
carbon dioxide to
chlorophyll
make food for the
(green pigment) plant
Classifying Living Things
Groups of Living Things
Sorting animals into groups is called classifying.
All organisms are split into five Kingdoms:
• Animal Kingdom: organisms that usually move around and find
their own food.
• Plant Kingdom: organisms that make their own food and do not
actively move around.
• Protist Kingdom: organisms that have single, complex cells.
• Moneran Kingdom: organisms that have single, simple cells.
• Viruses: organisms that are very simple usually comprising of a
nucleic acid molecule in a protein coat that is too small to be
seen by a light microscope and is able to multiply only within a
host’s living cells.
Classifying Living Things
Animal Kingdom: organisms that usually move around and find
their own food.
The two main groups of animals are vertebrates and
invertebrates.
• Vertebrates are all animals internal bones including a
backbone.
• Fish
• Amphibians
• Reptiles
• Birds
• Mammals
Classifying Living Things
• Invertebrates are all animals without internal bones.
• Arthropods: All the "jointed legged" animals. All of these animals have an
exoskeleton, meaning the skeleton is on the outside of the body.
Include: Insects, Arachnids, and Crustaceans
• Mollusk: Soft-bodied animals that sometimes have a hard shell.
Includes: Snails, Slugs, Octopus, Squid, Clams, Oysters, and Mussels.
• Annelid: Includes: Earthworms and Leeches.
• Rotifer: Tiny, microscopic animals with a wheel-shaped mouth and tiny
hairs.
• Nematode: Very tiny worms with no segments in their bodies. Also called
Roundworms.
• Tardigrade: Tiny, slow-moving animals with four body segments and
eight legs. Includes Water Bears.
• Cnidarian Phylum: Soft-bodied, jelly-like animals with tentacles and
venom glands. Includes: Hydra, Jellyfish, Anemones, and Coral.
• Echinoderm Phylum: Often spiny animals, with several "arms" reaching
out from the center of its body. Includes: Starfish and Sea Urchins.
• Platyhelminthes Phylum: Soft, flat-bodied worms. Includes: Planarians
and Tapeworm
Classifying Living Things
• Plant Kingdom: organisms that make their own food and do not actively
move around.
• Magnoliophyta Division: All "flowering" plants. These plants have leaves,
stems, and roots. After flowering, they form fruits with seeds. Includes most
crops, trees, shrubs, grasses, garden plants, and weeds.
• Coniferophyta Divsion: Plants that bear cones. Includes: Pine Trees and
Cedars.
• Pteridophyta Division: Plants that have roots and stems, but do not have
flowers or seeds. Instead, they spread with spores. Includes Ferns.
• Bryophyta Division: Plants with very small leaves and stems, with no roots
and no flowers. Usually grow very low to the ground. Includes: Mosses.
• Lycopodiophyta Division: Small plants with green, branched stems, scalelike leaves, and no flowers. Usually grow very low to the ground. Includes:
Club Mosses, Quillworts, and Spikemosses.
Classifying Living Things
• Fungi Kingdom: organisms that absorb food from living and non-living
things.
• Protist Kingdom: organisms that have single, complex cells.
• Moneran Kingdom: organisms that have single, simple cells.
• Bacteria Phylum: These organisms are extremely important and can
also be very dangerous. They live anywhere there is moisture, including
inside animal's bodies. Some carry disease.
• Cyanobacteria Phylum: These organisms are also known as Blue-green
Algae. These algae are different from the Green Algae found in the Plant
Kingdom.
END