The Vital Question 3 Flashcards
stromatolites
a mound built up of layers of cyanobacteria and trapped sediment, found in Precambrian rocks as the earliest known fossils, and still being formed in lagoons in Australasia. A stromatolite is formed as a result of calcium carbonate and other minerals and sediment precipitating out of the solution over the sticky layer mucilage that surrounded the bacterial colonies, which continued to grow upwards. “And there are structures resembling stromatolites, those domed cathedroasl of bacterial life, in which cells grow layer upon layer, the buried layers mineralising, turning to stone, ultimately building up into strikingly laminated rock structures, a metre in height.” (27) 1930s: from modern Latin stroma, stromat- ‘layer, covering’+ -lite.s Picture mat - picture layers of mat upon mat of Strow/ strew caclium carbonate and other sediments precipitating out of solution over the mat of cyanobacteria - light - colonies of cyanobactera need light so they move up above the layers of sediment repeating the process. .
calcareous
containing calcium carbonate; chalky. CaCO3 Calcium -carbonate MD - Calcium carbonate big circle and within circle is calcite. Chalk is calcerous and so is limestone. They contain calcium carbonate.
precipitate
Chemistry cause (a substance) to be deposited in solid form from a solution. • cause (drops of moisture or particles of dust) to b opposite of dissolve. precipitation is when rain, snow, sleet, or hail fall to the ground. they come out of the atmosphere. it also happens when a substance comes out of a solution. like the mineral that forms a yellowish layer on the bathtub after the water has gone down the drain.
cambrian explosion
the emergence of many new organisms including most ancestral lineages of present-day animal species that occurred at the beginning of the Cambrian period 541 million years ago. “Dozens of different animal phyla radiated in the cambrian explosion, for example, from sponges and echinoderms to arthropods and worms.” (33) Vincent Cambria most ancestral lineages of Cambria. 1 common ancestor - gay evolution - straight evolution - modern cambria. ancestor results in.
extremophiles
an organism that lives under extreme environmental conditions (as in a hot spring or ice cap)
. “…including eukaryotic extremophiles capable of dealing with high concentrations of toxic metals or high temperatures…” (43) phile - latin suffix “one that loves, likes, or is attracted to,” extreme - extreme enviornment
meiosis
The process of reductive cell division in sex, to form gametes which have a single complete set of chromosomes (making it haplid) rather than the two sets found in the parent cells (diploid).
“All [eukaryotes] are sexual, with a life cycle involving meiosis (reductive division) to form gametes like the sperm and egg, followed by the fusion of these gametes.” (42) MD (picture) Mitosis happens everywhere, even in my toe, Meiosis only happens in my OH! A gamete will end up with 23 chromosomes after meiosis, but independent assortment means that each gamete will have 1 of many different combinations of chromosomes.
mitosis
Mitosis is the noraml form of cell division in eukaryotes, in which chromosomes are doubled, then separated into two daugter cells on a microtubular spindle.
“All eukaryotes divide by mitosis, in which chromosomes are separated on a microtubular spindle, using a common set of enzymes.” (42) MD Mitosis happens everywhere, even in my toe, Meiosis only happens in my OH!
camera eye
camera eye, an enclosed structure with its iris and lens, liquid interior, and image-sensing retina.
“morphologically distinct types of eye evolve in different environments, as divergent as the compound eyes of flies and mirror eyes of scallops, or as convergent as the camera eyes that are so similar in humans and octopuses.
MD - documents “camera eye”
retina
the sensory membrane that lines the eye, is composed of several layers including one containing the rods and cones, and functions as the immediate instrument of vision by receiving the image formed by the lens and converting it into chemical and nervous signals which reach the brain by way of the optic nerve — see eye illustration.
laruen hill “retina or not you can’t hide, gonna find you” it is the immediate instrument of vision by receiving the
conjugation
Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells.
“Some may argue that bacteria practise a form of conjugation equivalent to sex, transferring DNA from one to another by ‘lateral’ gene transfer.” (46)
MD
recombination
the exchange of one piece of DNA for an equivalent piece from another source, giving rise to different combinations of genes (specifically alleles) on ‘fluid’ chromosomes.
“Sex invovles the fusion of two gametes, each with half the normal quota of genes, followed by reciprocal recombination across the entire genome.”
MD - video genetic recombination increases genetic variability .
Tiktaalik
An extinct fishlike aquatic animal that lived about 380–385 million years ago (during the earliest late Devonian Period) and was a very close relative of the direct ancestors of tetrapods (four-legged land vertebrates). The genus name, Tiktaalik, comes from the Inuktitut language of the Inuit people of eastern Canada and is a general term for a large freshwater fish that lives in the shallows
“An evolutionary intermediate is a missing link - a fish with legs, such as Tiktaalik, or a dinosaru with feathers and wings, such as Archaeopteryx.” (48)
MD - tik - has four legs except tiktaalik is the ancestor of tetrapods (four-legged land vertebrates), “like” - freshwater fish living in shallows.
entropy
the degree of disorder or randomness in the system. (Symbol: S)
“…Schrodinger’s other central tenet - that life resists entropy, the tendency to decay.”
MD - Kahn Academey illustration. entropy the more possible states a system has. small box the molecules are able to have more configurations the more molecules there are and the more space there is. think of a trophy.
greater degree of disorder and randomness the more molecules and space in a system. the more trophies and more space in a trophy room the more potential disorder - entropy. make the dots on a trophy platfrom.
plasmid
an extrachromosomal ring of DNA especially of bacteria that replicates autonomously and can pass cirectly from one bacterium to another.
“Plasmids - typically small indpendent rings of DNA carrying a handful of genes - can pass directly from one bacterium to another (via slender connecting tube) without any need to fortify themselves to the outer world.” (55)
MD - plasma fourth state of matter can spew out of a volcano like a plasmid can spew out of a bacteria during conjugation.
extrachromosomal
situated or operating outside the chromosome: extrachromosomal DNA.
MD - extraterrestrial. extra - outside, terrestrial - the earth.
nucleoid
The nucleoid (meaning nucleus-like) is an irregularly shaped region within the cell of a prokaryote that contains all or most of the genetic material, called genophore. In contrast to the nucleus of a eukaryotic cell, it is not surrounded by a nuclear membrane.
bacterial dna
a circular chromosome plus plasmids. The DNA of most bacteria is contained in a single circular molecule, called the bacterial chromosome. The chromosome, along with several proteins and RNA molecules, forms an irregularly shaped structure called the nucleoid.
MD - screenshot
immiscible
incapable of mixing or attaining homogeneity
“Oil and water are said to be immiscible - the physical forces of attraction and repulsion mean they prefer to interact with themselves rather than each other.” (57)
MD - im - not, miscible - (mixing) able to form
heat vs. temperature
Heat is the total energy of molecular motion in a substance while temperature is a measure of the average energy of molecular motion in a substance.
“Heat is the motion of molecules, their jostling and molecualr disorder. Entropy.”
MD - iceberg - more heat than match, match higher temperature. the speed at wich the molecules move. the to
oxidise
to combine with oxygen
Other chemicals then oxidize the sulfur dioxide to form sulfuric acid, which along with the nitric acid increases the acidity of the dewdrop.
—R. Monastersky
Should the cork be allowed to dry out, it will shrink and allow air to seep in and oxidize the wine.
—Peter D. Meltzer
“their components will react with oxygen - oxidise - slowly over time, and that ultimately erodes their structure and function, preventing them from springing back to life in the rigth conditions.
endothermy
physiological generation and regulation of body temperature by metabolic means : the property or state of being warm-blooded.
“That’s an interesting point in terms of the evolution of endothermy, or hot blood” (62)
lineage
lineage is a temporal series of organisms, populations, cells, or genes connected by a continuous line of descent from ancestor to descendent. Lineages are subsets of the evolutionary tree of life. Lineages are often determined by the techniques of molecular systematics.
MD picture of the lamprey line on the phylogentic tree from Khan academy.
derived trait
a derived trait is a trait that is present in an organism, but was absent in the last common ancestor of the group being considered.
Primitive traits are those inherited from distant ancestors. Derived traits are those that just appeared (by mutation) in the most recent ancestor – the one that gave rise to a newly formed branch. Of course, what’s primitive or derived is relative to what branch an organism is on.
MD - jaws example
revert (biology)
go back to an earlier form
“something could have evolved and then went away, reverting to an ancestral form.”
Old French revertir or Latin revertere ‘turn back.’
MD
phylogeny
The study of evolutionary lineages of a species, or group of species
MD - phylo - group, geny - genesis - the formation of something phylogenetic tree.
common ancestor
An ancestor shared by two or more descendant species
MD - tree from khan academy
Relatedness
In a phylogenetic tree, two species are more related if they have a more recent common ancestor, and less related if they have a less recent common ancestor.
MD - phylogeny diagram from khan academy
lens (of an eye)
a highly transparent biconvex lens-shaped or nearly spherical body in the eye that focuses light rays (as upon the retina).
“the lens completes the bending of light rays started by the cornea, thereby projecting a sharp, upside down, and reversed image onto the light sensitive retina lining most of the rear section of the eyeball…The lens is constructed from higlh specialized interlocking cells that are long, narrow, and very thin. Having lost most of their internal structures, these cells are filled with crystallins - special proteins that make the lens both trasnparent and flexible. Like the cornea, the lens has no blood supply to compromise its transparency. Instead, nourishment is absorbed from the aqueous and vitreous humors.” (177 How we Work)
MD - picture from way we work
light comes in from the cornea and pupil and hits the lens which focuses the light and projects it onto the retina which makes up the inner layer of the back of the eyeball.
cornea
the transparent part of the coat of the eyeball that covers the iris and pupil and admits light to the interior
“Just behind each eyelid is the sclera, the tough white protective coat that completely encases the eyeball except at the front, where the clear cornea provides a circular window through wich light rays can enter.” (175)
MD - picture from way we work.
Cornea is like the window that lets light into the eye.
rods (of the eye)
120 million rods in each eye works best in dim light, specializing in fuzzy monochrome images adn peripheral vision.
MD - a pen is rod shaped, but can only outline
a paint brush which provides more colored is cone shaped.
cones (of the eye)
6 million of the eyes photoreceptors that operate best in bright light, detecting colors and provding most detail.
photoreceptors
your retinas are loaded with millions of phtotoreceptors which do the crucial work of converting light energy into the electrical signals that your brain will receive. These receptor cells come in two forms - rods and cones.
Etymology: Gk, phos, light; L, recipere, to receive
centromere
the point or region on a chromosome to which the spindle (see 1spindle 2) attaches during mitosis and meiosis
MD - from Latin centrum (see center) + Greek meros ‘part.’ draw picture of a chromosome with a centromere and 1 chromatid and a centromere for 2 chromatid.
chromatid
one of the usually paired and parallel strands of a duplicated chromosome joined by a single centromere
picture of 1 and 2 chromatid both being referred to as 1 chromosome.
primitive trait
Primitive traits are those inherited from distant ancestors. Derived traits are those that just appeared (by mutation) in the most recent ancestor – the one that gave rise to a newly formed branch. Of course, what’s primitive or derived is relative to what branch an organism is on.
