Spontaneous generation has been offered as an explanation for:

a. the birth of live offspring from a mother

b. the germination of a seed

c. the appearance of maggots on rotting meat

d. all of the above

How did Redi test the hypothesis of spontaneous generation?

a. he placed meat in one container and left another empty. he then observed the containers for the appearance of maggots.

b. he placed meat in two containers and covered one of them. he then observed the containers for the appearance of maggots.

c. he placed meat in two containers and fly eggs in one of them. he then observed the containers for the appearance of maggots.

d. he placed the adult flies in two containers, one with meat in it and one without. he then observed the containers for the appearance of maggots.

What did Pasteur do in his experiments on spontaneous generation that other scientists before him had not done?

a. he boiled the broth in his flasks

b. he sealed the flasks

c. he used curved neck flasks and left them open.

d. he added microorganisms before he boiled it.

The age of the Earth is estimated to be approximately

a. 2 million years

b. 2 billion years

c. 2 trillion years

d. 4 billion years

Which of the following is not thought to have been a factor in the formation of Earth?

a. pieces of debris in space collided with earth, thereby heating it.

b. pieces of debris in space added to the size of earth

c. earth was formed from debris that circled the sun as it formed

d. formed from collision of two small stars.

If the half life of a radioactive isotope is 5000 years, how much will be left after 10,000 years?

a. all of it

b. one half the original amt

c. one quarter of orginal

d. none of it

The half life of a radioactive isotope

a. does not change

b. varies with the seasons

c. increases as isotope ages

d. fluctuates

The age of fossils, such as those of bones, can sometimes be determined by

a. observing their magnetism

b. measuring the amt of a specific radioactive isotope in the fossil bones

c. analyzing the DNA in bones

d. observing their developmental pattern

The half life of carbon-14 is 5730 years. How much of an inital amt of this substance would remain after 17, 190 years, which is three times its half life?

a. none

b. 1/2

c. 1/4

d. 1/8

Isotopes are forms of the same element that differ in

a. atomic number

b. number of electrons

c. number of neutrons

d. number of protons

Which of the following gases whas thought by Oparin to be part of Earth's early atmosphere?

a. oxygen

b. ozone

c. ammonia

d. carbon dioxide

Oparin believed that macromolecules such as proteins first appeared

a. in volcanoes

b. in the atmosphere

c. in water

d. on iron pyrite and clay.

Miller and Urey didn't use oxygen gas in their apparatus because oxygen

a. is not essential to most forms of life

b. doesn't react with ammonia, methane or hydrogen

c. would have lead to the formation of microorganisms

d. wasn't believed to have been present in earth's early atmosphere.

In Miller and Urey's experiment, they produced

a. energy

b. microorganisms

c. radioactive isotopes

d. amino acids

Miller and Urey's apparatus was designed to demonstrate that all life on earth might have originated from

a. radioactive decay

b. simple organic molecules

c. extraterrestrial life

d. none of the above

Experiments conducted by Miller and Urey have demonstrated that molecules important for life could have been produced in earth's early atmosphere. These molecules include amino acids, carbohydrates, lipids, ATP, and nucleotides of DNA and RNA. Which of the following suggests how the genetic material of cells may have evolved to give instructions for the functioning and replication of cells?

a. a spark of electricity can catalyze chemical reactions that produce proteins from DNA

b. Cells link amino acids together into proteins using instructions carried in the DNA and enzymes to catalyze the reactions.

c. RNA like enzymes can catalyze chemical reactions and some RNA molecules could be self replicating

d. chains of nucleotids form when water evaporates from a solution of nucleotides

RNA

a. was probably the first genetic molecule

b. can unergo natural selection and thus can evolve

c. probably evolved before DNA

d. all of the above

RNA

a. has a 3-D structure

b. is a nucleic acid

c. can act like an enzyme

d. all of the above

RNA molecules can

a. catalyze the synthesis of DNA

b. catalyze the synthesis of eukaryotic cells

c. produce complemetary copies of their own nucleotide sequence

d. all of the above

Presently, scientists think that DNA

a. evolved before RNA

b. evolved the same time as RNA

c. was essential for the formation of the first cells

d. evolved after RNA

Scientists think that the first cells resembled modern

a. animal cells

b. mitochondria

c. archaebacteria

d. chloroplasts

Scientists have inferred that the first cells were

a. prokaryotic and autotrophic

b. prokaryotic and heterotrophic

c. eukaryotic and autorophic

d. eukaryotic and heterotrophic

Which of the following is a true difference between photosynthetic organisms and chemosynthetic organisms?

a. they differ in the source of energy used to produce organic molecules

b. they differ in the source of carbon used to produce organic molecules

c. photosynthetic organisms are found of earth today, while chemosynthetic organisms are no longer found on earth

d. photosythetic organisms are eukaryotic while chemosythetic organisms are prokaryotic

The surface of earth is protected from ultraviolet rays by

a. oxygen

b. ozone

c. hydrogen

d. nitrogen

Which of the following is thought to have been an important early function of aerobic respiration

a. it enabled some early organisms to live on land

b. it consumed oxygen that could destroy chemicals in early organisms

c. it protected early organisms from UV radiation, which damages DNA

d. all of the above

Many scientists think that early aerobic prokaryotes invaded larger cells and eventually gave rise to

a. chloroplasts

b. DNA

c. mitochondria

d. ribosomes