Transcript Introduction to Living Things

CHARACTERISTICS OF LIVING THINGS
1. COMPOSED OF CELLS
2. OBTAIN AND USE FOOD FOR
ENERGY
3. REPRODUCE
4. RESPOND TO STIMULI
5. ADAPT TO THE ENVIRONMENT
6. REQUIRE WATER TO SURVIVE
7. MAINTAIN HOMEOSTASIS
8. HAVE A METABOLISM
9. PRODUCE WASTE
Honors Biology
Living things Obtain and Use
Food for Energy
LIVING THINGS ARE BASED ON A
UNIVERSAL GENETIC CODE

There is a specific molecule used within the
cells of ALL living things to store the complex
information they need to
Live
 Grow
 Reproduce


What is this molecule called??


DNA (Deoxyribonucleic Acid)
DNA is the genetic material of the cell which
contains codes for the building of proteins.
LIVING THINGS
ARE TAKEN AS A GROUP,
LIVING THINGS EVOLVE
Pass on traits (characteristics) from one
generation to the next by their DNA
 Cannot generally choose or change their
characteristics
 An organisms traits are largely
predetermined by their DNA


Though it may be influenced by their
environment
LIVING THINGS
ARE TAKEN AS A GROUP,
LIVING THINGS EVOLVE

Examples of Types of Traits:

Physical

Physiological

Behavioral
LIVING THINGS
ARE TAKEN AS A GROUP,
LIVING THINGS EVOLVE
Physical
Physiological
Behavioral
• Parts of the
cells/body
• Ex: polar
bears fur,
birds hollow
bones,
presence of a
backbone
• Processes
occurring
within the
cells/body
• Ex: warm vs
cold blooded,
photosynth.
• Survival
• Ex: Mating
rituals,
avoiding
predation, or
food-getting
migration
WHAT
KIND OF TRAITS ARE SHOWN?
HOW

How are traits controlled ??


Individual’s genes
In sexually reproducing species, variations
arise from unique combinations of the mother
and father’s genetic material


DO THESE NEW TRAITS ARISE??
Variations are differences in organisms
In sexually and asexually reproducing species,
variations can also arise from random/chance
mutations
Change the genetic material of a cell
 Mutations can be helpful, harmful, or have no
impact!

WHAT’S

A
MUTATION
ANYWAY??
Mutation

Change in the genetic material of a cell
AS
A GROUP, LIVING THINGS ADAPT TO
THEIR ENVIRONMENT OVER TIME

Variations may enhance an organism’s ability
to survive & reproduce


These traits are referred to as adaptations
What’s an adaptation?

Heritable characteristic that increases an
organism’s ability to survive and reproduce in an
environment
AS
A GROUP, LIVING THINGS ADAPT TO
THEIR ENVIRONMENT OVER TIME

Environment largely dictates what is an
adaptation and what is not.
A trait may benefit survival in one environment
and hinder survival in another
 Ex – think of a snowshoe hare trying to hide in a
NJ Forest!

AS
A GROUP, LIVING THINGS ADAPT TO
THEIR ENVIRONMENT OVER TIME


How do populations change/evolve over
time???
Natural Selection

The process by which organisms that are best
suited to their environment survive and
reproduce most successfully
(=survival of the fittest)

Individuals are selected, a species adapts and
evolves
EXAMPLE

OF EVOLUTION
Two shades of peppered moths (light/dark)
lived simultaneously in England before the
industrial age.
The trees were light at the time since they
were covered in “lichens” (a fungus/algae)
 Which moths were harder to spot “before”
the Industrial revolution???




Birds spotted the darker moths and the
population of darker moths decreased
In other words, the “lighter” ones were
“selected for”
During the IR, there was so much pollution
that the darker lighter colored lichen on the
trees were killed, thus making the trees
appear darker…

Which moths were harder to spot “after” the IR?
Birds spotted the lighter moths now and the
population of lighter moths decreased.
 In other words, the “darker” ones were
“selected for”


This shows how the environment drives
natural selection (influences the selection
of traits)


Each time an organism reproduces, there is a
chance that the DNA of the offspring will lead
to new and different traits which may
enhance their survival.
If the trait benefits the organism, the
organism is more ‘fit’ for survival and
reproduction of another generation of
offspring (their genes are getting passed on)
The new trait may be passed on to the next
generation of offspring
 Eventually, if successful then this trait will
be present in a greater % of the population


The group of organisms can be said to have
adapted to their environment

As one adaptation follows another, eventually
the species may undergo subtle or even
drastic changes. Over time groups of
organisms can become different enough from
one another that they are considered a new
species.
EVOLUTION

Change over time


The process by which modern organisms have
descended from ancient organisms
Evidence points to a common ancestor of all
life forms which dates back over 3.5 billion
years.
WE

Over time there is damage to DNA and cells


Wear out, despite constant maintenance and
repair throughout the organism’s life time
Cannot always maintain homeostasis in all
environmental conditions


CAN’ T LIVE FOREVER!
Cannot continue its metabolism and maintain
homeostasis, its life will cease.
Earth has a limited supply of resources

Death – materials in cells are recycled back into
the environment for use by new generations of
living things
ORGANISM
ORGANISM
APPROX LIFESPAN
APPROX LIFESPAN
(years
(years)
Bristlecone Pine
3,000-4,700 years
Toad
36
Redwood
1,000-3,500
Deer
35
Douglas Fir
750
Cobra
28
Galapagos Tortoise
193
Tiger, Cat
25
Giant Tortoise
152
Bat
24
Box Turtle
123
Cow
22
Turkey Buzzard
118
Queen Ant, Chicken, Sheep
15
Swan
102
Tiger Salamander
11
Parrot
80
Green Frog
10
Eleplant
69
Hummingbird
8
Horned Owl
68
Queen Bee, Gerbil
5
Catfish
60
House Mouse, Hamster, Rat
4
Eagle
55
Most Insects
< 1year
Horse
50
Adult Honeybee Workers
6 weeks
Decomposers are essential to the recycling of
materials between the living and non-living
portions of every ecosystem
 All this dead ‘stuff’ has run out of energy. It
can’t grow any more.



But it is still vital to life, because it contains
atoms that are the basic building blocks of all
living things.
These atoms get recycled into the food web with
the help of organisms called decomposers.
VIRUSES




There is some debate over whether viruses
are living or nonliving. Most agree that they
are nonliving. Why?
They are unable to INDEPENDENTLY carry
out all life processes. They are known as
“obligate intracellular parasites”.
They are particles made of nucleic acid and
protein that can replicate only by infecting
living cells.
Do not belong to any kingdom and don't
contain any cells. Therefore, they are
considered nonliving.