Download File - SCIENTIST CINDY

Define the Following Terms:
Cyanobacteria
Photosynthesis
Hydrocarbons
Consumer
Producer
Autotroph
Archaebacterial
Heterotroph
Carnivore
Omnivore
Herbivore
Ecology
Community
Biosphere
Population
Ecosystem
Cells
Organism
Symbiosis
Mutualism
Parasitism
Commensalism
Endosymbiotic theory
List and describe the 7 characteristics of life? To be considered alive, an object must exhibit all 7 of the
characteristics of living things.
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Order - 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.” The cell
is the fundamental unit of life.
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Reproduction – propagation of the species. All living things have the ability to 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.
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Growth / Development - Grow in cell SIZE – cell cannot sustain its own size so it splits into 2.
Grow in cell NUMBER. Cells change over time by different parts of the DNA being activated at
different points in time.
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Process Energy – All living things rely on energy and must obtain energy and change it into a
form in which it can be used biologically.
1. 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.
2. Animals use sugars provided by plants and other organisms to produce energy in the
form of adenosine triphosphate (ATP).
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Responds to Environment – all living things respond to environment factors. Environmental
factors include basic things such as pH, temperature, pressure, light, food, odors and sound.
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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.
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Examples of what things are regulated:
1. body temperature
2. the pH of extracellular fluids
3. Osmolality - the concentrations of sodium (Na+) and calcium (Ca2+) ions
4. amount of glucose
5. Food and water intake, metabolism and excretion
6. Sleep/wake cycles – rest
7. Stress / relaxation balance
8. Hormonal Balance
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Evolutionary Adaptation – genetic traits that are beneficial for survival will persist in future
generations of that species due to environmental and sexual pressures.
List and describe the levels of organization of life.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
ATOM - The simplest unit of life is the atom, like oxygen.
MOLECULE - Two or more atoms is a molecule, like dioxide.
MACROMOLECULE - Many molecules is a macromolecule, such as a phospholipid.
CELL – the cell is the basic unit of life. Multiple macromolecules form a cell, like a club cell.
TISSUE - A group of cells functioning together is a tissue, for example, Epithelial tissue.
ORGAN - Different tissues make up an organ, like a lung.
ORGAN SYSTEM - Organs work together to form an organ system, such as the Respiratory
System.
ORGANISM - All of the organ systems make a living organism, like a lion.
POPULTION - A group of the same organism living together in an area is a population, such as a
pride of lions.
COMMUNITY - Two or more populations interacting with each other form a community, for
example, lion and zebra populations interacting with each other.
ECOSYSTEM - Communities interacting not only with each other but also with the physical
environment encompass an ecosystem.
BIOSPHERE - All of the ecosystems make up the biosphere, the area of life on Earth.
Explain the theory of chemical evolution as it pertains to the origin of life on Earth.

The origin of life on this planet seem to have emerged from chemistry. This called chemical
evolution. We can make LIFE from nonliving chemistry. Molecules in water will spontaneously
form orderly structures, such as the phospholipid bilayer that is the structure of our cell
membranes.
Are viruses considered alive? Why or why not?
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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, though is classified as
non-living.
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 have genetic material, can reproduce (with the help of a host cell), evolve, respond to
their environment, etc.
What are the 3 domains of life?
 Bacteria
 Archaea
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Eukaryota
What are archaea?

The Archaea are prokaryotes, meaning that they have no cell nucleus or any
other membrane-bound organelles in their cells. Archaea were initially classified
as bacteria, receiving the name archaebacteria (in the Archaebacteria kingdom),
but this classification is outdated. Archaeal cells have unique properties
separating them from the other two domains of life (bacteria and eukaryote).
Archaea use more energy sources than eukaryotes: these range from organic
compounds, such as sugars, to ammonia, metal ions or even hydrogen gas. Salttolerant archaea (the Haloarchaea) use sunlight as an energy source, and other
species of archaea fix carbon; however, unlike plants and cyanobacteria, no
known species of archaea does both.
Describe the first living organisms that we have physical evidence of.
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Cells resembling prokaryotes appear. These first organisms are chemoautotrophs: they
use carbon dioxide as a carbon source and oxidize inorganic materials to extract energy.
How old is the Earth?
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4.5 billion years old. The planet Earth forms from the accretion disc revolving around the
young Sun with organic compounds (complex organic molecules) necessary for life
having perhaps formed in the protoplanetary disk of cosmic dust grains surrounding it
before the formation of the Earth.
Explain the first global event called the “Great Oxygen Event” that changed our atmosphere to
contain more oxygen.
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Photosynthesizing cyanobacteria evolved. They used water as a reducing agent, thereby
producing oxygen as a waste product. The oxygen initially oxidizes dissolved iron in the
oceans, creating iron ore. The oxygen concentration in the atmosphere slowly rose,
acting as a poison for many bacteria and eventually triggering the Great Oxygenation
Event.
Explain the endosymbiotic theory of how Eukaryotic cells appear.
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The endosymbiosis theory explains the origins of organelles such as mitochondria and
chloroplasts in eukaryotic cells. The first eukaryotic cells may have evolved when one
prokaryotic cells engulfed another. The prokaryote (bacteria cell) that was then trapped
inside. Both cells entered a symbiotic relationship, a close association between different
types of organisms over an extended time. However, to be specific, the relationship was
endosymbiotic, meaning that one of the organisms (the bacteria) lived within the other
(the eukaryotic cells). According to endosymbiosis theory, an anaerobic cell probably
ingested an aerobic bacterium but failed to digest it. The aerobic bacterium flourished
within the cell because the cell's cytoplasm was abundant in half-digested food
molecules. The bacterium digested these molecules with oxygen and gained great
amounts of energy. Because the bacterium had so much energy, it probably leaked
some of it as adenosine triphosphate into the cell's cytoplasm. This benefited the
anaerobic cell because it was now able to breathe aerobically, which means more
potential for energy gain. Eventually, the aerobic bacterium could no longer live
independently from the cell, and it, therefore, became a mitochondrion.
What evidence do we have of the endosymbiotic theory with regard to mitochondria?
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The mitochondria reproduce independently using binary fission (asexually) and have
their own bacterial plasmid which is a circular strand of DNA.
What are the characteristics of bacteria?
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All bacteria are prokaryotic. This means that they do NOT have membrane-bound
organelles or a membrane-bound nucleus.
They have genetic material that is a circular form of DNA called a plasmid.
They have organelles but they are not compartmentalized within membranes.
They can be harmful or helpful.
They are simpler
They evolved first.
What are the characteristics of eukaryota?
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More complex – DO have membrane-bound organelles and a membrane-bound nucleus.
Evolved by the endosymbiotic theory – cell “ate” another cell.
Includes both plant and animal cells.
Are more complex
Evolved later
Describe how energy is obtained for the following classifications of organisms:
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Autotrophs: make their own food
o Chemotrophs: derived from chemical reactions
o Phototrophs: derived from sunlight (photosynthesis)
Heterotrophs: obtain food by breaking down organic molecules from their environment
Why is all life on earth carbon-based?
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All life as we know it is Carbon-based
The Carbon atom has the ability to create up to 4 strong bonds, allowing for the
complexity needed for life.
What 4 atoms make up 96% of all living matter on Earth?
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Carbon, Hydrogen, Oxygen and Nitrogen
Describe the atom.
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Atoms are the fundamental unit of all matter.
Atoms are 99.999999999999999% empty space.
Almost all of the mass of the atom is in its nucleus.
The nucleus of an atoms contains positively-charged protons and uncharged neutrons.
Electrons “orbit” the nucleus and are negatively-charged.
How are molecules formed?
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Molecules are form when two or more atoms come together and form a chemical bond.
Describe the 3 types of chemical bonds.
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Ionic – one atoms “steals” one or more electron from another atom. The result are 2
separate ions (usually occurs in water) one will be positive (cation), the other will be
negative (anion).
Covalent – there are 2 types of covalent bonds.
o Polar Covalent bond – electrons are unequally shared resulting in a polar
molecule with a partial positive charge on one end and a partial negative charge
on the other end.
o Non-Polar Covalent Bond – electrons are equally shared between two atoms.
This results when an atom bond either to itself or with another atom that has a
very similar electronegativity.
Hydrogen bonds – weak bonds that are form with a hydrogen atom. Hydrogen bonds
are very important for life processes. For example, hydrogen bonding occurs DNA so
that the strand can separate during replication and hydrogen bonds are important for
dissolving of substances in water.
The four basic categories of molecules for building life are _______.
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Carbohydrates - sugars
Lipids - fats
Proteins – amino acids
Nucleic acids – building block of DNA
Explain the food chain in term of energy flow in the ecosystem.
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Energy enters the biological system as light energy, or photons.
Producers - Light energy is transformed into chemical energy by organisms through
cellular processes including photosynthesis and respiration.
Some of this energy is converted to heat energy and can no longer be recycled in the
system. Only 10% of the energy is transferred to the next level.
The energy flows from Photons  Producers  Primary Consumers  Secondary
Consumers  Tertiary Consumers  and so on.
What are the 3 dispersion patterns seen in population ecology. Hint : Dispersion pattern - The way
individuals are spaced within an area
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Clumped dispersion – grouped in patches
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uniform dispersion – evenly spread out over a given area
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Random dispersion – unpredictable
Describe the 3 types of survivorship curves.
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Type I - For a Species that exhibits a type I survivorship curve – Most of the individuals
of that species will survive until they reach “old age”. Examples are seen in Humans and
Large mammals.
Type II - For a Species that exhibits a type Ii survivorship curve – the survivorship of that
species remains relatively constant over the lifespan. Example are seen in Hydra,
Invertebrates, Lizards and rodents.
Type III - For a Species that exhibits a type IIi survivorship curve – Most of the individuals
of that species will die young, but the ones that live on to adulthood will live a relatively
long time. This is observed in animals who have large numbers of offspring, but provide
little care for them., such as fish and oysters.
How has the population of humans expanded since 1800?
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Global human population growth amounts to around 75 million annually, or 1.1% per year.
The global population has grown from 1 billion in 1800 to 7 billion in 2012. Advancements such
as the Industrial Revolution, Flushable Toilet, Germ Theory, Antibiotics, and Sewer Systems lead
to a rapid population increase.
Describe the 2 idealized patterns of population growth:
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Exponential (or “geometric” for discrete version)
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In the exponential model of population growth, you do not see the effect of limiting
factors. Population undergo rapid and explosive growth of population. This is often the
case when a new species is introduced to a new environment with lots of resources and
very few predators, diseases etc. After some time, this will no longer be the case and
they will begin to exhibit a logistical growth model instead.
Logistic (s-shaped)
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In the Logistic model of population growth, you see the limiting effects of the ecosystem
begin to change the survival rates and life-span demographics of the population. This
happens as the population grows, approaching the Carrying capacity (K) (the limitations
of that environment). Other limiting factors that contribute to this model are
1) Predation
2) Parasites
3) Food sources
4) Illness
5) Change in environment
Explain how water is important for life processes.
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Life and its chemistry are tied to water. Life began in water and evolved there for 3 billion
years before spreading onto land. And all life, even land-dwelling life, is still dependent on
water. Your cells are 75% water. The composition of the water surrounding the cells
(extracellular fluid) is similar to sea water. When life evolved to move out of the ocean, we
had to take the ocean with us! Water is the most abundant compound on the surface of
Earth.
How can you tell how an atom will bond just by looking at its position on the periodic table? HINTS:
Shell 1 can hold up to 2 electrons. Shell 2 can hold up to 8 electrons. Atoms react in such a way that
their outer shell is filled. We know the number of bonds that can be made by an atom by looking at its
position on the periodic table.
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The elements on the periodic table are organized by the atomic number which is the
number of protons in the nucleus.
We know in an atom, the number of electrons will be equal to the number of protons.
Since atoms bond using unpaired electron in their outer shell (called valence electrons) and
we know the hints above, we can count how many electrons are available for boding.
Group 1 atoms can form 1 bond.
Group 2 atoms can form 2 bonds.
Group 3 atoms can form 3 bonds.
Group 4 atoms can form 5 bonds.
Group 5 atoms can form 3 bonds.
Group 6 atoms can form 2 bonds.
Group 7 atoms can form 1 bond.
Group 8 atoms are inert and do not like to bond with anything.