Ch. 22

There are four stages that we know for sure about the begings of life. What are the four stages?

Slow accumulations of molecules in the ocean into organic molecules is calle what?

Based largely on geological data, h2 methane and ammonia and water vapor existed and then the formation of hydrogen cyanide (HCN) and formaldehyde (CH2O). Such molecules are precursors of more complex organic molecules. These precursors also combined to make larger molecules such as the amino acid glycine. At the end of 1 week of operation, 10–15% of the carbon had been incorporated into organic compounds

Theory that organic molecules where placed here or where carried on a commet or merteroite.

key organic molecules may have originated in deep-sea vents, which are cracks in the Earth’s surface where superheated water rich in metal ions and hydrogen sulfide (H2S) mixes abruptly with cold seawater. These vents release hot gaseous substances from the interior of the earth at temperatures in excess of 300°C

Organic polymer may have been formed on the surface of?

cell-like structuresmay have originated when polymers were enclosed by a?

An aggregate of prebiotically produced molecules and macromolecules that acuquired a boundry.

What are the four key features that make probiotics possible precursors to living cells?

Cells could have evolved from droplets that form spontaneously from the association of charged polymers such as proteins, carboydrates, or nucleic acids surrounded by water

The second possibility is that probionts evolved from vesicles surrounded by a lipid bylayer known as?

What are the 3 key functions of RNA?

Occurs when a chemical within a mixture has special properties or advantages that cause it to increase in number compared to other chemicals in the mixture.

is a hypothetical period on early Earth when both the information needed for life and the enzymatic activity of living cells were contained solely in RNA molecules

These are made up of a combination of the 20 amino acids.

Are the preserved remains of past life on earth

Scientists that study fossils are called?

What kind of rock are fossils preserved in?

A common way to estimate the age of a fossil is by analyzing the decay of radioisotopes within the accompanying rock, a process called

is the length of time required for a radioisotope to decay to exactly one-half of its initial quantity.

What are some reasons that fossils are biased?

is a time line of the Earth’s history and major events from its origin approximately 4.55 billion years ago to the present

The names of several eons and eras end in -zoic meaning

the complete loss of a species or group of species

What where the major environmental changes?

The shift of landmasses.

many species to go extinct at the same time

These cells arose during the archean eon

Organisms may follow two different strategies to obtain energy; what are they?

their energy is derived from the chemical bonds within organic molecules they consume

directly harness energy from either inorganic molecules or light.

These layers are mats of mineralized cyanobacteria, one layer on top of the other

relationship is one in which two different species live in direct contact with each other

relationship, in which a smaller organism (the symbiont) lives inside a larger organism (the host)

The first animals where

This era had a warm and wet climate, no evidence of ice. rapid diversity of species called () explosion. Also, mainly shelled animals

The first vertebrates showed up how long ago?

Climate was warm and moist. marine invertbrates. First plants started to show

Stable, high ocean levels, new fishes, and vascular plants.

Dry climate, seed plants, tetrapods started showing up.

Coal deposits, Large plants and trees, first flying insects, emmurgence of reptiles.

This was where Pangea started. fernlike plants replaced by gymnosperms (modern conifers). Largest known mass extinction.

Reptiles plentiful and dinos, and first true mammals.

Gymnosperns, mammals not prelvant. Reptiles dominant. Manin dinos.

This period had flowering plants, dinos, mass extinction of dinos.\

This period is where hominoids showed up.

refers to a subset of hominoids, including modern humans, extinct human species (for example, of the Homo genus), and our immediate ancestors

Ice ages, hominins became more human like, 1.8-today