Bio 120 Lecture 5 And 6

Front 1

describe the conditions of primordial earth

Back 1

covered with lava

lots of meteorite bombardments

took 500 million years for earth to cool down

Front 2

living organisms lived how many years ago

Back 2

3.75 billion years ago

Front 3

oldest bacteria fossils have been found are how many years ao

Back 3

3.4 billion years ago

Front 4

what are the 5 steps for the origin of life by abiogenesis

Back 4

1) organic monomers form inorganic molecules

2) monomers linked together to form polymers

3) enclosing of organic molecules into membrane bound protobionts

4) RNA was the initial information storage but then DNA came later

5) establishment of energy forming pathways to bring in energy to sustain life

Front 5

how were organic molecules that are necessary to support life originate to primordial eath

Back 5

were formed de novo on earth itself

Front 6

how were monomers first formed

Back 6

spontaneously formed in shallow oceans

Front 7

what was the Oparin-Haldane hypothesis

Back 7

a reactive atmosphere with electrons and hydrogens nessisary to convert inorganic into C02 and then into organic carbons

Front 8

how did polymers come from monomers

Back 8

the oceans turned into "prebiotic soup" and then uv light from the sun formed the polymers

Front 9

Stanley Miller created the Miller-Urey experiment to test which theory

what was his experiment

Back 9

the Oparin Haldane theory

*he simulated lightening and proved its possible to produce organic molecules spontaneously from inorganic precursors.

Front 10

what is the formula for atmosphere

Back 10

CO CO2 N2 H20

Front 11

what were some problems of the Miller-Urey experiment

Back 11

the intensity of the energy was too high

he used the wrong formula for atmposhpere. lol

Front 12

How did RNA form into DNA

Back 12

by genetic mutations

Front 13

differences between RNA and DNA

Back 13

DNA is more stable, has enzymes, double helix

RNA less stable, has ribosomes (slower than enzymes as catalysts), single helix

Front 14

how long ago was the first "primitive organism"

Back 14

3.4 billion years ago

Front 15

what are Stromatolites

Back 15

formed by cyanobacteria. they were layered accretionary structures formed in shallow seas.

Front 16

describe mitosis and give a brief description of each

Back 16

prophase: tightly condenses chromosomes

Prometaphase: nucleaur envelope dissociates, spindle apparatus moves to where the condensed chromasomes are located

metaphase: the chromosomes line up in the middle

Anaphase: the chromosomes split apart

Telophase: chromosomes decondense

Front 17

when is meiosis used instead of mitosis

Back 17

meiosis is used in the division of diploid cells to haploid cells

Front 18

describe the process of meiosis

Back 18

Interphase I: G1, S, and G2 phase to prepare for the division

Prophase I: synapiss and crossing over occur, along with condensing

Metaphase I: Lines up in the middle

Anaphase I: chromosomes are pulled apart

Interkinesis: cells prepare to divide again but do not replicate

Prophase II: condense

Prometaphase II: same as mitosis

metaphase II: line up in middle

Anaphase II: pulled to opposite poles

telophase: daughter cells are haploid, chromosomes consist of 2 chromosomes

Front 19

a haploid cell + haploid cell = what cell

Back 19

diploid cell

Front 20

how does the spindle form in animal cells

Back 20

the centrosome splits in 2 and the centrosome controls the spindle

Front 21

how does the spindle form in plant cells

Back 21

(plant cells lack centrosomes) they use Microtubule Organizing Centers (MTOC)

Front 22

what is a kinetochore microtubule

Back 22

area on the chromatids where the spindle fibers attach to during cell division so they can pull them apart.

Front 23

where are sister chromatids held together

Back 23

At the centromere

Front 24

when does the metaphase stage end

Back 24

when the sister chromatids start to split

Front 25

what does the cleavage furrow do

Back 25

divides the cell into 2

Front 26

what is synapsis

Back 26

the process of homologous chromosomes finding each other and pairing up to form bivalents

Front 27

what is crossing over

Back 27

the exchanging of genetics between two bivalents. (after crossing over the arms separate but still remain stuck resulting in a x shaped chiasmata)

Front 28

what does crossing over create

Back 28

a new genetic variation

Front 29

why do the chromosomes along the metaphase plate (middle) line up randomly

Back 29

produces different mixes of chromosomes resulting in genetic variation

Front 30

2n= how many chromosomes

Back 30

2n=46

Front 31

n=?

Back 31

23. n=23. n stands for 23. so 2n= 23+23 which equals 46.