bioquest 14

Question 1

biogenesis

Answer 1

all living things come from other living things

Question 2

spontaneous generation

Answer 2

living things come from non-living things

Question 3

Francesco Redi

Answer 3

put meat in jars (one covered and one uncovered) in the covered jars no flies were found, in the uncovered jar maggots were found. Conclusion: flies only come from other flies

Question 4

Lazzaro Spallanzani

Answer 4

boils broth in one covered flask and one uncovered flask. uncovered flask becomes cloudy with bacteria. Covered flask remains the same. People were skeptical because they believed that spallanzani had boiled the broth too long and the vital force had been killed

Question 5

vital force

Answer 5

something in the air that can create life

Question 6

Louis Pasteur

Answer 6

concludes spontaneous generation theory once and for all. put broth in flasks with curved neck, boils it and waits a year. broth remains clear (b/c of curved neck, vital force could enter but bacteria couldnt) after a year broke off curved neck and the broth became cloudy after a day

Question 7

earth originated how long ago and how was this found out

Answer 7

4 billion years ago- found out through fossil record and radiometric dating of rock

Question 8

radiometric dating

Answer 8

use of radioactive isotopes to determine the age of rocks/fossils (by measuring the quantity of that radioactive isotope you can determine the age)

Question 9

isotopes

Answer 9

same element but with different number of neutrons

Question 10

radioactive isotopes

Answer 10

unstable and emits particles of energy (radioactive decay)

Question 11

half-life

Answer 11

the length of time it takes for 1/2 of any size sample of an isotope to decay to a stable form- rate of decay

Question 12

carbon 12

Answer 12

not radioactive

Question 13

carbon 14 and what is it’s half life?

Answer 13

radioactive- half life of 5730 years

Question 14

to date extremely old rocks you must..

Answer 14

use elements with extremely long half lives such as uranium and thorium (if the half life of carbon isn’t long enough)

Question 15

Alexander Oparin and John Haldone

Answer 15

believed that earth’s early atmosphere contained no oxygen but had NH3 (ammonia), water vapor, carbon dioxide, water and CH4- and that b/c of high heat and lightening these gases formed simple organic compounds -he didn’t test this theory

Question 16

Stanley Miller and Harold Urey

Answer 16

tested Oparin theory

Question 17

Organic compounds from beyond earth theory

Answer 17

simple organic compounds could have arrived via meteorites

Question 18

sidney fox

Answer 18

did research on physical structures that may have given rise to first cells

Question 19

microspheres

Answer 19

composed in lab- spherical in shape with protein membranes-look like cells and bud into “new cells”- dont have all characteristics of life and no hereditary material

Question 20

coacervates

Answer 20

composed in lab- collections of droplets created from lipids, amino acids and sugars- round and can grow “- dont have all characteristics of life and no hereditary material

Question 21

hereditary material is stored in….

Answer 21

DNA

Question 22

RNA has several shapes (just like protein)- these shapes are dictated by….

Answer 22

placement of hydrogen bonds

Question 23

there is speculation that because of RNA’s different shapes, RNA has the capability of behaving like……

Answer 23

a protein

Question 24

Thomas Cech

Answer 24

discovered that a type of RNA can also act as an enzyme (named it Ribosyme)- rybozime acted as a catalyst for its own replicatoin- speculation that RNA was the first hereditary material. Cech was able to create replicating RNA in a lab

Question 25

the first cells

Answer 25

anaerobic and not photosynthesizing (earth's atmosphere had no oxygen) prokaryotic-looked like today's archaea instead- they were chemosynthesizers

Question 26

chemosynthesizers

Answer 26

make organic compounds from CO2 (dont photosynthesize and need another way of getting energy) can use SO2, oxidize organic compounds can live in harsh environments- swamps and deep sea

Question 27

endosymbiosis

Answer 27

theory by lyn margulis. first eukaryotes formed when the first synthesizing cells were engulfed by non photosynthesizers. engulfed cells got protection and larger cell got a method of energy synthesis and a way to photosynthesize. little cells that were engulfed became future organelles (mitochondria and chloroplasts- have own DNA and replicate differently than rest of cell)

Question 28

first known photosynthesizers were called

Answer 28

cyanobactera

Question 29

lyngbya

Answer 29

a genus of modern day cyanobactera

Question 30

stromatolites

Answer 30

colonies of lyngbya that formed layered structures -fossilized forms