Minkley BIO 111 Exam 2 University of Rochester

Coelom

An open-cavity in Animalia located between the gut and the body wall. used to gain girth

Binary fission

The type of reproduction that prokaryotes undergo. Cells about to divide replicate their genetic material and then pass one copy to each daughter cell

Mitosis

Process in which a eukaryotic cell replicates its genome- the nucleus splits in two, and the parent cell then divides into 2 daughter cells

Polyploidy speciation

When a genome is duplicated either because genes do not go through reduction during meiosis (autopolyploidy) or when genomes of different species combine (allopolyploidy)
Often results in sympatric speciation

Sympatric speciation

Occurs when a single species diverges into 2 species despite occurring in same location.
Can occur by other modes other than polyploidy

Cretaceous period

-lasted from ~145 - 66 million years before present time
-notable for the origin of the flowering plants near the beginning of the period and is characterized by an asteroid strike at the end that resulted in the extinction of the dinosaurs

Anthropocene Period

-period we live in at the present
-defined by the geological and biological impacts humans are having on the planet

Acoelomate

lack of enclosed body cavity, instead the space between the gut and the muscular body wall is filled with masses of cells called mesenchyme

pseudocoelomate

body cavity enclosed by mesoderm ONLY on the outside

coelomate

body cavity enclosed on both inside and outside by mesoderm

Cambrian period

lasted from ~540 - 485 million years ago. is noted for the large number of animal phyla that originated during this period

ribozyme

enzymes that are made of RNA

enzyme

biological catalysts that accelerate, or catalyze, chemical reactions

choanoflagellates

closest relatives of animals. some are motile and unicellular, others are colonial. their cell structures is the same as that of choanocytes in sponges

choanocytes

SYNAPOMORPHY FOR PORIFERA, specialized cells found in sponges that have a collar of microvilli and a central flagellum

colloblasts

SYNAPOMORPHY FOR CTENOPHORA, adhesive and retractable tentacles

nematocyst

SYNAPOMORPHY FOR CNIDARIA, spears used to capture prey

protostome

mouth forms first from blastopore

deuterostome

anus forms first from blastopore; totipotent

processes that changed atmospheric conditions:

-volcanic activity
-chemical reactions (that took oxygen in from the atmosphere)
-photosynthesis

synapomorphies of all life:

-DNA replication
-central dogma
-ribosomal machinery for protein synthesis
-universal genetic code
-citric acid cycle

criteria for first pre-biotic molecule:

-all functions in cell must be encoded by a jack-of-all trade type of molecule (DNA, RNA, proteins)
-individual polymer units must be formed by natural organic chemistry (DNA, RNA, proteins)
-ability to encode information (DNA, RNA)
-ability to catalyze its own replication (RNA)
-ability to catalyze other reactions (RNA, proteins)

endosymbiosis

hetertrophic cell consumes other cell (but does not digest, instead they coexist)
more genomes in a cell, the more they shrink

pleistocene overkill

hypothesis that humans hunting methods cause the extinction of some species (especially large mammals); proof that not all extinctions are caused by asteroids or natural causes, can trace the history of human settlements and can see that all large mammals went extinct around the same time

origin of earth

~4.6 billion years ago

3 characteristics of life:

1. accurate replication
2. bound within a cell/container
3. metabolization

miller-urey experiment

recreate the earth's atmosphere and composition a the time of the first cell's formation
-heated water and other biomolecules and let it turn into vapor, then lightning was replicated and provided a continuous energy source, the solution settle and 17/20 amino acids necessary for early life were replicated

Koch's postulates

a pathogen can only be considered the cause of a disease if it is found in all cases of the disease
1. a pathogen may be considered the a cause of the disease if it's found in every patient suffering from the disease
2. a pathogen should grow on a culture medium
3. if a pathogen is taken from a culture and introduced to a susceptible organism, it causes a disease
4. a pathogen, extracted from the material taken from an ill patient, should grow, producing pure strains of the same bacilli

biofilm

protective layers that bacteria clusters secrete that provides an antibiotic protection layer

plastids

double-membrane bound organelle, usually involved in synthesis and storage of food, commonly found in cells of photosynthesis organisms

Fick's law

=-(membrane permeability)(surface area)(concentration gradient)

metazoa

multicellular, heterotrophic, collagen, unique muscle and nervous tissue, gene arrangement (hox), life cycle with diploid phase dominant (2n)

diploblastic

2 cell layers: an outer ectoderm and inner endoderm

triploblastic

3 cell layers: with addition to inner and outer layer, have a layer in between called the mesoderm

totipotency

can differentiate into anything, cell type not yet determined (deuterostome in 8 cell stage)

How many genomes are in a mouse cell?

2- nucleus and mitochondria

How many genomes are in green algae?

3- mitochondria, nucleus, chloroplast

What evidence suggests micelles had membranes of fatty acids rather than phospholipids?

fatty acids are much simpler structurally than a phospholipid bilayer and form a "container" at low concentrations as well as maintaining their structure long-term. phospholipids are too complex to have been the membrane of protocells as they are impermeable to nucleotides, etc. require energy, pores, and transporters

what is the adaptive advantage of biofilms for bacteria?

biofilms form a protective layer over bacteria. this is one way that bacteria diminish the effects of antibiotics, for example

assume you have tested carbon-14 in a sample of horse teeth and found there was 25% less in the teeth than in atmosphere. what information do you need to determine how long ago the horses died?

information is needed on how long the half-life of carbon-14 is

what are three advantages of using the ribosomal RNA to understand evolutionary relationships of bacteria over other molecules?

1. rRNA was present in the common ancestor of all life and is therefore evolutionary ancient
2. no free-living organism lacks rRNA, so rRNA can be compared throughout the tree of life
3. rRNA plays a critical role in translation in all organisms, so later transfer of rRNA genes among distantly related species is unlikely
4. rRNA has evolved slowly enough that gene sequences even from distantly related species can be analyzed

How is the process of binary fission in bacteria different than mitosis in eukaryotes?

BF and mitosis both make genetically identical copies of the original cell. the major difference is that BF is initiated as a response to the environment and mitosis is initiated by signals from nearby cells as tissues grow or when there is a need to repair damage