Transcript File - SCIENTIST CINDY

https://www.powtoon.com/onlinepresentation/bBb5Ju585Th/what-islife/?utm_source=Transactional&utm_medium
=Email&utm_campaign=Transactional-Publishsuccess&mode=movie#/
The 7 Characteristics of Life
https://quizlet.com/9365982/biology-7-characteristics-of-life-flash-cards/

Order

Responds to Environment

Reproduction

Regulation (homeostasis)

Growth / Development

Evolutionary Adaptaion

Process Energy
Not all scientists
agree exactly about
what makes up life.
Many characteristics describe
most living things. However,
there are examples that would
seem to “break the rule”.
For example, something nonliving being classified as living
or something living being
classified as non-living.
So first, let’s take a closer look at the
“7 characteristics of life”.
If you look closely at any organism
you can see that it is made of
structures called cells.
Sometimes this rule will be worded
as “all living things are made of one
or more cells.”
Living things have a highly ordered
structure that has the cell as the
basis.
The Levels of Organization of Life Can
Potentially Go Infinitesimally Small or
Infinitely Large!

Atoms divide into subatomic particles  Subatomic particles are made up of
quarks  Quarks are made up of ???

The biosphere is part of the solar system  Solar system is part of the galaxy
 Galax is part of the Universe  Universe is part of the multiverse??  ??
Spontaneous generation 
Spontaneous generation or anomalous generation is an obsolete body of
thought on the ordinary formation of living organisms without descent from
similar organisms. Typically, the idea was that certain forms such as fleas
could arise from inanimate matter such as dust, or that maggots could arise
from dead flesh.
Spontaneous
generation –
…a funny
outdated idea.

Fleas come from dust particles.
Spontaneous generation –
…a funny outdated idea.
 Fleas
come from dust particles.
Spontaneous generation –
…a funny outdated idea.

Mice come from wheat and dirty
laundry.
https://www.youtube.com/watch?v=Dlb
h6024R1c
All Living
Things Have
the Ability to
Reproduce.
Propagation
of the
species.
To be considered alive, an object must exhibit all of the
characteristics of living things.
WELL…… Hybrid animal are sterile and cannot produce
offspring, but we consider them alive.
https://www.youtube.com/watch?v=AMD6c9o
N1Ys
Living Things Reproduce
A very important part of the life of living things is the ability and
opportunity to reproduce, to create offspring. Reproduction is the
process of one or more living things creating another living thing.
Grow in cell SIZE – cell
cannot sustain its own
size so it splits into 2.
Grow in cell NUMBER.
https://www.youtube.com/watch?v=GoHUli_uRY
Cells change over time
by different parts of the
DNA being activated at
different points in time.
https://www.youtube.com/watch?v=GoHUli_uRY
You know, when I was a little stem cell, I didn’t
know what I wanted to be either!
But I am so confused!
How do organisms process energy?
Plants - get energy from the sun and use carbon dioxide and
water in the process called photosynthesis to
produce energy in the form of sugars.
Animals use sugars provided by plants and
other organisms to produce energy in the form of adenosine
triphosphate (ATP).
Living things respond
to their environment.
Environmental factors
include basic things
such as pH,
temperature,
pressure, light, food,
odors and sound.
Regulation (Homeostasis)
The property of a system in
which a variable is actively
regulated to remain very
nearly constant, despite
changes in the animal’s
environment.
https://www.youtube.com/watch?v=9RLnlX
Nlfdk
https://www.youtube.com/watch?v=6fhbbF
d4icY
Examples of what things are regulated:
•
•
•
•
•
•
•
•
body temperature
the pH of extracellular fluids
Osmolality - the concentrations of sodium (Na+) and calcium (Ca2+) ions
amount of glucose
Food and water intake, metabolism and excretion
Sleep/wake cycles – rest
Stress / relaxation balance
Hormonal Balance
Is Life Spontaneous? (a Default?)

https://www.youtube.com/watch?v=n_m83ZuYHUA

Scientists can make primitive cells out of molecules on their own.

Adding fatty acids makes them grow.
Is Life Spontaneous? (a Default?)

https://www.youtube.com/watch?v=fgQLyqWaCbA

All of life probably originated from 1 single cell.

Advantageous mutations survive, other don’t.
Original of Life

We see life became more complex over time.

Life emerged from Chemistry

Chemistry of life is organized into metabolic
pathways (chemical reactions that process
energy)

Amino Acids, sugars, bases come together to
form DNA and molecules.

1828, Urea was made – what they thought the
VITAL FORCE, was understandable.
Origin of Life

We can make LIFE from nonliving chemistry

Was life on Earth seeded by an ancient asteroid?

Chemical evolution – with sunlight, complex orderly structures will
self-assemble.
Fire. People used to think it was alive.
1) it reproduces (something near fire can catch on fire)
2) it grows (the more fuel you add, the bigger it gets)
3) it has metabolism (it eats wood, cloth, flesh...)
3) it needs air (it "breathes" oxygen but dies if non is
available)
4) It does react to the temp around it.
For about 100 years, the scientific
community has repeatedly changed
its collective mind over what
viruses are.
1)First seen as poisons,
2) then as life-forms,
3) then biological chemicals,
4) and today seen as being “a gray
area” between living and nonliving
Viruses – Alive or Not?
 The
word “virus” has
its roots in the Latin term
for “poison.”
 In
the late 19th century researchers realized that
certain diseases, including rabies and foot-andmouth, were caused by particles that seemed to
behave like bacteria but were much smaller.
Viruses – Alive or Not?
https://www.youtube.com/watch?v=Rpj0emE
GShQ
Because they were
clearly biological
themselves and could be spread
from one victim to another with
obvious biological effects, viruses
were then thought to be the simplest
of all living, gene-bearing life-forms.
Domains of Life -
 Use
to be 2 (1990)
prokaryotic
(bacteria) and
eukaryotic, now
known as 3.
Bacteria 
https://www.youtube.com/watch?v=gEwzDydciWc
https://www.youtube.com/watch?v=Lg-1Vv4-58M
Bacteria are tiny living beings
(microorganisms)

They are neither plants nor animals

They belong to a group all by
themselves.
Bacteria are tiny single-cell
microorganisms, usually a few
micrometers in length that normally
exist together in millions.
 They can be harmful or helpful.

Eukaryote -
https://www.youtube.com/watch?v=ruBAHiij4
EA
 More
complex – have membranebound organelles and a
membrane-bound nucleus.
 Evolved
by the endosymbiotic
theory – cell “ate” another cell.
 Includes
cells.
both plant and animal

Methane –

Thermoacidifiles – hot sprong – hydrogen sulfide –

Halofiles – high salinity

Eu
https://www.youtube.com/watch?v=ZskEUGRl
qrI
Have you heard?
Genus Demodex; live exclusively on human
 2 species: D.folliculorum (top) and D.brevis (bottom)

http://blogs.discovermagazine.com/notrocketscience/2012/08/31/everythingyou-never-wanted-to-know-about-the-mites-that-eat-crawl-and-have-sex-onyour-face/
Two types of cells:
Prokaryote
vs.
Eukaryote
Prokaryote vs. Eukaryote
Characteristics
Size
Prokaryotes:
Archae and Eubacteria
1-10 m
Eukaryotes:
Protists, Plants, Fungi,
Animals
100-1000 m
Genetic materials - Circular DNA
- DNA in nucleus
including plasmids, not bounded by membrane
bound by a membrane - No plasmid
- Genome made up of - Genome made up of
a single chromosome several chromosomes,
thus contains many
more genes than
prokaryotes
Cell division
Binary fission
Mitosis and meiosis
Reproduction
Asexual is common
Sexual is common
Prokaryote vs. Eukaryote (cont.)
Characteristics
Prokaryotes:
Archae and Eubacteria
Eukaryotes:
Protists, Plants, Fungi,
Animals
Number of cells
Unicellular
Most are multicellular
Organelles
No membrane-bound
organelles such as
mitochondria, chloroplast
etc.
No nucleus
Membrane-bound
organelles present
Metabolisms
-Many carry out
metabolism under no O2
condition
-Metabolism processes
carried out in the
cytoplasm
-Most require O2
-Metabolism processes
carried out in membranebound organelles such as
mitochondria, chloroplast
etc.
Endosymbiosis Theory
How have prokaryotes possibly become eukaryotes?
Eukaryotic cells are believed to be the result of a symbiotic
union of separate prokaryotic cells
domain Archae and
Eubacteria
(generally referred as
Bacteria)
Shared characteristics of Archae and
Eubacteria
no
nucleus
All single-celled.
no membrane-bound organelles
DNA as a single chromosome.
Reproduce asexually by binary
fission.
domain: Archae
 Archae means primitive or early
 Often live extreme environments
Eg. high salt concentrations, temperature
or acidity;
 Most live in environments with no
oxygen
 Hypothesis: all life domains are
descended from the ancestors of this
group
Classification of domain
ArchaeaBacteria

By their habitats
A. Anaerobic methanogen: those live in O2-free places (e.g. gut of animals and
produce CH4)
B. Halophiles: salt-loving archaea
C. Thermophiles: those inhabit hot, acidic environment such as hot springs
domain Eubacteria or Bacteria
domain Bacteria
1.
2.
3.
4.
Classification
Shapes
Respiration
Reaction to staining
Reproduction
1. Bacterial shapes
http://www.youtube.c
om/watch?v=6p9e0o
olbmE
Classification – Shape
Singular Plural
coccus
cocci
bacillus
bacilli
Shape
round
rod
spirrillum spirrilla
spiral
Advantages
Resists drying out
greater surface area
= higher nutrient
absorption
can move through
fluids with less
resistance
domain Bacteria
2. RESPIRATION
Classifying bacteria by respiration
1)
Obligate aerobes: require oxygen
2) Obligate anaerobes: grow only in absence of oxygen
3) Facultative anaerobes: can survive with or without oxygen
Nutrition: vocabulary revision
 Autotrophs:
make their own food
 Heterotrophs: obtain food by breaking
down organic molecules from their
environment
 Chemo- derived from chemical
reactions
 Photo- derived from sunlight
Bacterial Nutrition
Mode of nutrition
Photoautotroph
Energy
source
Light
Carbon
source
CO2
Inorganic
chemicals
CO2
(e.g. cyanobacteria)
Chemoautotroph
(e.g. Ferrobacillus
ferrooixdans)
Photoheterotroph
(e.g. Heliobacter polyri)
Chemoheterotroph
(e.g. Methanococcus
jannaschii )
Light
Organic
compounds
Organic
Organic
compounds compounds
4. Bacterial reactions to being stained

Gram staining: a staining technique by Hans Christian Gram in 1884

Divide bacteria into 2 groups:
Gram negative
Peptidoglycan
absent in cell wall
Gram positive
Peptidoglycan
present in cell wall
Gram staining procedure
BACTERIAL ASEXUAL REPRODUCTION
Called “binary fission”

bacterial DNA replicates and divides

a cross wall develops and the two genetically identical cells separate
http://www.youtu
be.com/watch?v
=DY9DNWcqxI4
&feature=related
True!
Conjugation- not true
sexual reproduction

Cell to cell contact is made
with a cytoplasmic bridge

Plasmids (small circular
DNA); contain genes
different from those in the
bacterial chromosome

Plasmids are transferred
from the donor to the
recipient

Recipient now has new
genes from donor (ie. Gene
for antibiotic resistance)
ENDOSPORE FORMATION
 Adaptation
to survive unfavourable
conditions eg. Anthrax forms spores
 Cell wall becomes thick
 resistant to heat
and not easily
destroyed
 bacterium emerges
when suitable
conditions return
USEFUL BACTERIA
Production of
vinegar
 fixing nitrogen in
soils
 dairy products
(cheese, yogurt….)
 decomposers in
nutrient cycles
 source of some
Antibiotics
 Clean up oil spill

HARMFUL EFFECTS
BACTERIAL DISEASES
1. Leprosy
2. Tetanus
3. Botulism
4. Cholera
DEFENSE AGAINST DISEASE

Body provides own defenses (skin, acidic stomach, lysozyme in eyes, immune
system)

sterilization/disinfection of surfaces can reduce disease further (wash your
hands)

Antibiotics are chemicals that kill bacteria but don’t harm host cells

Bacteria have evolved to resist many of today’s antibiotics
Antibiotics
and Antiseptics
Joseph Lister created the first antiseptic, an

acid to spray on tables and instruments before
surgery (1860)
 The Discovery of Penicillin (1928)
Alexander Fleming
Noticed mold growing on petri dishes
Bacteria did not grow where the mold was
He isolated the chemical that killed bacteria,
but it was not stable
 Howard Flory continued the work, later
stabilized the chemical
 Fleming and Flory received the Nobel Prize in
1945




Bacterial growth:
- Zones of inhibition around
the disks shows
the effectiveness of the
antibiotics
Antibiotic resistance:
Ability of bacteria to
grow in the presence
of chemicals meant to
destroy them
What is the zone of
inhibition on this agar?
Which disk(s) is
most effect at
inhibiting the
growth of bacteria
on this agar?
Drug screening: Bacteria can be grown on agar plates
to check for antibiotic resistance
Which Petri disk show
more antibiotic resistance?
Bonnie Bassler - PrincetonU
How Bacteria Talk to each
other?
•http://www.ted.com/talks/lang/eng/bonnie_bassler_
on_how_bacteria_communicate.html
Quorum sensing:
the phenomenon
whereby the
accumulation of
signalling
molecules enables
bacteria to sense
their number so
they can launch
group behaviour
(e.g. virulence etc.)
Review
1. Label the bacteria by shape
dicocci
streptococci staphylococci
2. What is a bacteria called that must live in oxygen?

Obligate aerobe
3. How do bacteria reproduce?

Binary fission (asexual) & conjugation
4. Bacteria on a
pin. What
shape?
a. Cocci
b. Bacilli
c. Spirilla
5. What survival
advantage
does this
shape bring to
the bacteria
For your interest
Next
2 slides connect with your
antibiotic resistance reading
articles
Drug- resistant Superbugs
non-typhoidal
salmonella
Vancomycin-resistant
Staphylococcus aureus
Neisseria gonorrhoeae
Streptococcus
pneumoniae
tuberculosis
Pseudomonas
aeruginosa
Get Smart: Know When Antibiotics Work
Q. What kinds of infections are caused by viruses and
should not be treated with antibiotics?
 cold, flu, sore throat (except strep. throat),
cough, bronchitis, ear infections are viral
infections shouldn’t be cured with antibiotics
Q. Can one strain of bacterium
become resistance to multiple drugs?
 Absolutely YES!
E.g. P. aeruginosa causes eye
infections, skin rashes, ear
infections, after surgery infection,
widely spread in hospital
Multi drug-resistant
Pseudomonas
aeruginosa
http://www.cdc.gov/getsmart/antibiotic-use/antibiotic-resistance-faqs.html
domain Bacteria
domain Bacteria