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90 Cards in this Set

  • Front
  • Back
When was Earth formed?
Universe-13.7 BYA called Big Bang
solar system- 5 BYA
Earth and planets- 4.5 BYA
What was early Earth like?
very hot, atmosphere consisted of nitrogen-co2-CO (carbon monoxide)-hydrogen-water, no free oxygen, high energy environment
What are organic molecules?
are those that contian carbon chemically linked to H. Includes food, fuel, and wood. Produced by plants and algae during photosynthesis.
Miller-Urey experiment
1953, a recirculating system of boiling and condensing water, the gases (CH4,NH3,H2,H20) and electric sparks to stimulate lightening. Brownish organic matter formed which contained small organic molecules important in living organisms (amino acids, lipids).
Why was the Miller-Urey experiment significant?
It was the first experiment for abiotic synthesis of organic matter. It put scientific theories about the origin of life on a solid experimental basis.
What are some alternate sources of organic matter?
Meteors and comets, hydrothermal vents
polymer formation
large molecule that is important bc DNA, RNA, protein cells depend of these large molecules for life
is one unit or cell capable of creating more cells: autocatalytic reaction
is the first reproducing unit
What does RNA have to have?
genetic info (sequence of bases), and specific shapes (proteins) that have catalytic activity (speed up reaction like enzymes)
What is DNA?
It is the blueprint for making protiens.
What was the first reproducing unit during the evolution of life?
short RNA molecules
What are ribozymes?
They are RNA molecules that function as enzymes.
Why is evolution a necessary condition for life?
It is the scientific explanation for the diversity of life on Earth, explains the similarities of life forms, and differences between organisms, their origins, history and etc.
What is the plasma membrane?
It surrounds the cell, and is a thin layer of lipids and proteins. It separates life from non-life in all cells.
Explain microspheres.
when simple lipids and proteins will self-assemble, and have been produced from organic matter recovered from meteorites and organic scums on clay minerals
What do all organisms need to live?
energy and carbon sources
What are autotrophs?
AKA-producers, "self-feeders" that make their own food
What are heterotrophs?
AKA-consumers, "other-feeders" that can't make their own food and must get it performed from their environment.
What are the two types of autotrophs?
Photoautotrophs and Chemoautotrophs
What are Photoautotrophs?
they obtain carbon from CO2, and convert it to organic matter using light energy to power. Ex. plants, algae, some bacteria (cyanobacteria)
What are Chemoautotrophs?
They obtain their carbon from CO2 and convert it to organic matter , but they use energy they release form energy-rich chemicals found in the environment (H2S, NH3, H2, FE2+) as the source of energy for this conversion. ex. some bacteria and many archaea. Those are the basis of the food chain in deep-sea hydrothermal vents.
How do Heterotrophs obtain their carbon and energy sources?
from organic matter (the food they eat) ex. animals, fungi, and most bacteria
What do autotrophs function as in the ecosystem?
collectors and concentrators since they collect carbon and enery to form organic matter consisting of concentrated carbon and energy.
Whad do heterotrophs function as in the ecosystem?
scatterers and recyclers bc when they eat and use the carbon and energy in organic matter, they release CO2, minerals and heat energy.
What are droplet cells?
They were the first, simple, living entities recognized as cells. They have a plasma membrane enclosing 50 RNA genes, that coded 50 short proteins. These proteins carry out primitive metabolism, transforming organic molecules into a more useful form and transforming engergy into ATP to power cellular metabolism.
True or False, DNA is more stable than RNA?
In modern cells what does RNA do?
it transfers information between DNA and protein production and retains some catalytic activity.
What are anaerobes?
cells that are more primitive, and function without oxygen
What are aerobes?
cells that fuction with oxygen
Do organisms in the bacteria and archaea domains have prokaryotic or eukaryotic cells?
Do orgainsisms in the eukarya domain have prokaryotic or eukaryotic cells?
What is the pyhlogenetic tree of life?
it shows that all known life on Earth has a common ancestor. The DNA-containing ancestor is at the lowest fork in the tree. Archaea and Eukaryotes are more closely related to each other than to bacteria.
What was Whittaker's major and lasting contribution?
it was to establish the plant, animal, and fungi kingdoms on the basis of nutrition: photoautotrophy, ingestive heterotrophy, and absorptive heterotrophy
When did DNA-containing cells evolve?
3.8 and 3.5 BYA
What are the two stable isotopes that Earth's carbon comes in?
C12 (abundant) and C13 (rare, one extra neutron,heavier)
What were the characteristics of the ancestor of the archaea?
prokaryotic, anaerobic, thermophilic, and chemoautotrophic
What is an interesting fact about the domain archaea?
found in extreme environments & of the three domains, archaea is the least changed from ancestral condition
What are the three major groups of archaea?
Thermophiles, Methanogens, and extreme halophiles
Describe thermophiles
prefer hot, acidic, sulfur-containing environments such as hot springs, volcanic vents and hydrothermal vents.
Describe methanogens
are methane producers, obligate anaerobes (can only grow in anaerobic habitats), and are found in organic matter ex. sewage treatment plants, swamps
Describe extreme halophiles
prefer to live in very salty places ex. Great Salt Lake and the Dead Sea. they are all aerobes, heterotrophic, and are most advance of the archaea
explain the other archaea known only by their genes
arachael genes in places with moderate environments, but can't be grown in culture
What were the characteristics of the ancestor Domain Bacteria?
prokaryotic, anaerobic, thermophilic, and photoautotrophic
Describe present-day bacteria
aerobic and heterotrophic
Chacteristics of Domain Bacteria
tiny cells, surrounded by a plasma membrane, cytoplasm contains ribosomes to make proteins, no membrane-bound organelles, DNA not surrounded by a membrane, have bacterial cell wall that is located outside the plasma membrane and determines their shape
What are the cell shapes of Domain Bacteria?
spheres (coccus, Streptococcus), rods (bacillus), and spirals (spirillum)
What is a special type of spiral cell?
spirochetes, is an organism responsible for syphilis and Lyme disease
What are endospores?
bacteria found in soil can produce these, they function to allow the organism to survive harsh conditions ex. Anthrax
What is flagella?
helps bacteria to swim. Bacterium flagella is a semi-rigid helix that rotates at its base
What is chemotaxis?
process which bacteria can move toward the source of food or away from the source of a toxin- movement occurs in runs and tumbling
Describe anaerobic photoautotrophs
have a less complex type of photosynthesis than plants, found in anaerobic habitats ex. shallow muddy sediments w/ low O2 and light, don't release O2 during photosynthesis
Describe Photoautotrophs
AKA-cyanobacteria, have advanced and normal type of photosynthesis, found in algae and plants, release O2 wich all aerobic organisms need for cellular respiration
common in soil, get energy from inorganic molecules in the environment, convert NH3 to NO3 and convert CO2 to organic matter
saprobic heterotrophs
live on dead organic matter, are decomposers, recyclers, and scatterers, are absorptive heterotrophs
ingestive autotrophs
eat things and digest food internally, not bacterium
absorptive heterotrophs
ex. bacteria and fungi, live within food supply, release digestive enzymes
What is probiotics?
is a new field of medicine that treats disease by using harmless bacteria to displace pathogenic bacteria
Nitrogen Fixation
important metabolic process, converts N2 into ammonium which can be used by plants, requires the input of energy and is a key part of the nitrogen cycle
Characteristics of Cyanobacteria
blue-green color, most evolved bacteria, live in water (illuminated)
When was oxygen produced and the Earth oxygenated?
3.5 BYA, but for the first 1.5 BYA O2 reacted with iron atoms to form rust- complete oxygenation took 3 billion yrs
Why was O2 production by cyanobacteria significant?
By completing the burning process, aerobic respiration recovers 18 more times usable energy (ATP). Oxygen and aerobic bacteria helped in the evolution of muticellular eukaryotes. Some O2 in the atmosphere was converted to ozone which absorbs UV light and makes it possible for life to exist in shallow water or on land.
How can O2 be bad?
Activated forms of O2, free radicals, have an unpaired electron that can do damage to cellular molecules. They are the cause of degenerative diseases. Vitamins C and E help eliminate bad O2.
What are examples of unicellular organisms?
single bacterial cell, most bacteria, all archaea, most protists
multicellular organisms
cell specialization (lose capacity to divide, provide greater efficiency of function), communication between cells, maintain stable environment, organize their cells into tissues of similar cells
a cell specialized for nitrogen fixation, provides a very strong case for multicellularity
structured communities, slime production is their behavior, help bacteria maintain position in a current, and provides a habitat and food for amoebas and other protozoa
Characteristics of the ancestor Domain Eukarya
prokaryotic, anaerobic, heterotrophic, phagotrophic(engulfing food particles by phagocytosis), and lacked cell wall
Function of cytoskeleton
cytoplasmic framework, composed of tiny microtubules and microfilaments, controls cell shape, movement, cytoplasmic streaming, and phagocytosis
Significance of cytoskeleton
was the key evolutionary innovation, definitive characteristic of pro-eukaryotes, allow the pro-eukaryote to engage in phagocytosis
pro-eukaryotes have this organized set of microtubules used for attachment and feeding
internal membrane system
is an interconnected system of membranes including the nuclear envelope, endoplasmic reticulum, and golgi bodies connected to plasma membrane
Do prokaryotes sexually reproduce?
no, they exchange genetic material, but aren't involved in the fusion of gametes (like eukaryotes)
Haploid cells
one set of chromosomes, n stands for haploid set of chromosomes
Diploid cells
tow sets of chromosomes, 2n diploid set of chromosomes
The human body cells are.....
diploid--> 46 chromosomes (23 sets), one by the father and the other by the mother
Human gametes (sperm and eggs)
haploid with 23 chromosomes each
How is a diploid cell formed?
when haploid cells fuse in a process called fertilization
a diploid cell that is formed as a result of fertilization
haploid cells are produced when...
a diploid cell undergoes meiosis
when a haploid cell divides by mitosis..
2 haploid cells are produced
when a diploid cell divides by mitosis..
2 diploid cells are produced
special kind of cell division of diploid cells to produce haploid sperm or egg cells
the first eukaryotes were..
what are the three different life cycles?
Diploid, Haploid, The alternation of generations life cycle
Diploid Life Cycle
phase where the action is, where cells are growing and undergoing cell division by mitosis. Found in animals; zygote,grow,cell division,produce a multicellular individual. The gametes are the only haploid cells. Gametes only fuse in fert. and never divide by mitosis.
Haploid Life Cycle
first type of eukaryotic life cycle, found in protists and fungi, undergo cell division by mitosis, diploid zygote never undergoes mitosis. Germination involves meiosis to form haploid cells
The Alternation of generations life cycle
found in all land plants and is a combination of haploid and diploid life cycles. results in two multicellular organisms. Diploid generation is called sporophyte. Haploid generation is called the gametophyte.
diploid generation since plants produce haploid spores by meiosis
haploid generation since plants produce gametes