Life and Its Beginning

Question 1

an idea that life could appear from non-living matter or inanimate object.

Answer 1

Spontaneous generation or abiogenesis

Question 2

abiogenesis is proposed by who and contradicted by who?

Answer 2

proposed by Aristotle and contradicted by Francesco Redi

Question 3

is the belief that life originates from pre-existing life

Answer 3

Biogenesis

Question 4

spontaneous generation is disproved by whose experiments?

Answer 4

it is disproved by Redi and Pasteur’s experiments

Question 5

explain Francesco Redi’s experiment

Answer 5

disproved abiogenesis using maggots that arose in decaying meat (maggots in meat in open container; no maggots in sealed containers)

Question 6

tested whether or not microorganisms can appear spontaneously after boiling

Answer 6

John Needham (Needham’s Experiment)

Question 7

English scientist that tried to disprove spontaneous generation

Answer 7

John Needham

Question 8

explain Needham’s experiment:

Answer 8

sealed a bottle of gravy, then heated it to kill any life; found life several days later, which he claimed came from the gravy.

FLAW w/ his experiment: the flask was not sealed and was exposed to air

Question 9

stated that life occurred from something that entered the unsealed flask and that it was the one responsible for life to grow

Answer 9

Lazzaro Spallanzani

Question 10

disproved Needham’s experiment

Answer 10

Spallanzani’s Experiment

Question 11

explain Spallanzani’s experiment:

Answer 11

used the same method as Needham’s but used two containers (one unsealed, and one sealed)

using broth in flasks that were both heated, he waited for growth. no growth in sealed flask, growth in unsealed flask.

Question 12

suggests that new bacteria appear only when they are produced by existing bacteria

Answer 12

Louis Pasteur

Question 13

explain Pasteur’s experiment:

Answer 13

using control and experimental groups he checked for cell growth. in the control group no growth was observed because it is sealed; while in the experimental group where neck is broken, outside air can carry microorganism leading to cell growth.

Question 14

Pasteur’s conclusion:

Answer 14

cells can only arise from pre-existing cells

Question 15

Early beliefs about the Origin of life

Answer 15

• Divine creation
• Spontaneous origin
• Panspermia
• Electric spark theory
• Deep-sea vent theory
• Physio-chemico theory

Question 16

it is believed that life forms and everything in the universe were created through a super natural power rather than naturalistic mean

Answer 16

Divine creation

Question 17

life evolved from inanimate matter; before life could evolve, simple molecules combined to form complex molecules

Answer 17

Spontaneous origin

Question 18

life arose outside earth and life that forms were transported from another planet to seed life on earth

Answer 18

Panspermia

Question 19

it proposes that a meteor or cosmic dust may have carried to earth significant amount of organic molecules which started the evolution of life

Answer 19

Panspermia

Question 20

life originated from chemical substances through a gradual process of change under the influence of reducing atmosphere (absence of free molecular oxygen in the primitive earth)

Answer 20

Physico-chemico theory

Question 21

lightning may have provided the spark needed for life to begin

Answer 21

Electric spark theory

Question 22

can generate amino acids and sugars from an atmosphere loaded with water, methane, ammonia, and hydrogen

Answer 22

Electric spark theory

Question 23

suggests that life may have begun at a submarine hydrothermal vents spewing key hydrogen-rich molecules

Answer 23

Deep-sea vent theory

Question 24

their rocky nooks could then have concentrated these molecules together and provided mineral catalysts for critical reaction

Answer 24

Deep-sea vent theory