Bio
Which of these is NOT a component of metabolism?
photosynthesis cellular respiration synthesis of organic molecules decomposition None of the answers are correct
What is the primary source of most of the energy for organisms living on Earth?
sunlight
Sulfur (S) has a molar mass of 32 g/mol. How many moles of sulfur are in 64 grams?
2 moles This answer choice is correct because 1 mole of sulfur has a mass of 32 g. The mass of two moles is double, or 64 grams
Carbonic acid has the formula H2CO3. Given that hydrogen (H), carbon (C), and oxygen (O) have molar masses of 1, 12, and 16, respectively, what is the molar mass of carbonic acid?
62 g/mol
Which of the following statements about types of experimental setup is correct?
A controlled experiment is one in which the experimental group receives the treatment and the control group does not. A natural experiment is one in which two different natural populations are compared. A regression analysis experiment is one in which varying levels of treatment are compared. An active controlled experiment is one in which a new treatment is compared to an old one. All of the answers are correct.
Which of the following best describes an essential element?
An essential element is one that is necessary for an organism's survival.
In ocean acidification, the following reaction occurs: CO2 + H2O = H2CO3 = H+ + HCO3- = 2H+ + CO32- Which of the following statements about ocean acidification is NOT true?
As a result of more CO2 entering the ocean, the level of CO32- will increase, which will cause CaCO3 to dissolve.
Which of the following statements about hydrogen bonding and water is true?
Hydrogen bonding occurs between the hydrogen atom of one water molecule and the oxygen atom of another water molecule.
How is DNA similar in prokaryotic and eukaryotic cells?
In both cells, DNA is a double helix. In both cells, DNA contains the genetic information on how to make proteins for various life functions. In both cells, ribosomes are needed to translate the information in DNA into proteins. In both cells, DNA is made of the same bases.
Why is carbon capable of forming single and double bonds?
It has four valence electrons.
How does the modern system of biological classification differ from that of Linnaeus?
It is based on evolutionary relationships.
Which of these is a characteristic of a good hypothesis?
It is based on previous observations or results
Which of the following elements can be classified as a noble gas?
Kr (krypton)
Given that milk has a pH of 6 and lemon juice has a pH of 2, which statement is correct?
Lemon juice is 10,000 times more acidic than milk This answer choice is correct because pH is a log scale, and a pH difference of 4 corresponds to a hydronium ion concentration ([H3O+]) difference of 104, or 10,000.
How is natural selection related to evolution?
Natural selection is one of several mechanisms by which populations evolve.
Evolution is considered the core theme of biology. Which of the following would NOT be considered a valid argument for why this is so?
Natural selection is the only explanation for the diversity of life.
What would have to happen in order for a polar covalent bond to form
One atom would have to share electrons unequally with another atom. why: polar covalent bonds involve unequal sharing of electrons among atoms. Note that no electron transfer takes place.
Why is the relative abundance of carbon in organisms greater than its relative abundance in Earth's crust?
Organisms sequester specific elements to maintain life's processes.
Penguins in Antarctica are superb swimmers, but they walk awkwardly and cannot fly. There is evidence that penguin ancestors could fly long ago. How might natural selection explain this?
Shorter wings may have helped ancestral penguins survive in their environment by enabling them to swim better, and so genes for shorter wings became common.
What happens to water molecules as the temperature of water drops below 4°C but before it reaches 0°C?
The kinetic energy of water molecules decreases, and the breaking and re-forming of hydrogen bonds slows down.
Which of these statements is a consequence of the oxygen atom in a water molecule being more electronegative than the hydrogen atoms in that water molecule?
The oxygen atom attracts electrons more strongly than the hydrogen atoms
What is one limitation of the ring model of atomic structure?
The ring model does not realistically depict the relative sizes and distances of the protons and electrons.
Complete the following sentence: Capillary action, or movement of water up a thin tube, is due to...
adhesion and cohesion.
Phosphorus (P) often occurs as a waxy solid in its natural state. If you subdivide a piece of phosphorus until you have the smallest conceivable amount, do you end up with an atom or an element?
an atom
How does science define the term 'energy'?
as the ability to do work
Why do scientists who explore evolutionary relationships often study ribosomal genes?
because they code for universal features of all organisms
Identify the process or processes that require energy.
breaking chemical bonds photosynthesis movement of molecules transferring energy from one form to another All answers are correct.
What is the role of many fungi in the cycling of carbon in an ecosystem?
breaking down and recycling organic molecules from dead organisms and was
How might a scientific theory be modified
by the uncovering of new information
Which element is present in all organic compounds?
carbon
What process moves carbon from living organisms to the atmosphere
cellular respiration
What type of chemical bond is found in the methane molecule?
covalent single bond why: methane molecule consists of one carbon atom bound to four hydrogen atoms. The carbon forms one covalent single bond with each hydrogen atom.
Which term describes the data that are collected during an experiment?
dependent variable
Students compared their resting heart rate to their heart rate after exercise. They measured their resting heart rate after sitting for five minutes; they then did 50 jumping jacks and afterward measured their heart rate. What was the dependent variable of this study?
heart rate
Which of the following is a form of energy
kinetic energy chemical energy ultraviolet light X-rays
Which of the following is an outcome of the Miller-Urey experiment?
t showed that complex organic compounds could form spontaneously from inorganic compounds. It caused biologists to view natural phenomena in terms of physical and chemical laws. It raised considerable controversy that prompted additional scientific inquiry. Scientists began to propose alternative theories to explain how organic molecules formed and how life came into existence. All answers are correct why:The reaction produced simple organic molecules like formaldehyde and hydrogen cyanide, as well as more complex organic molecules like amino acids and hydrocarbons. It caused biologists to view natural phenomena in terms of physical and chemical laws. Since this experiment, scientists have debated and tested the results. Finally, as a result of this experiment, many scientists began to develop alternative scenarios to explain how organic molecules formed and how life came into existence
Which of these is a consequence of evaporative cooling?
the fact that sweating helps reduce body temperature
What is the primary difference between protons and neutrons?
their charge
Complete the following sentence: A buffer is typically a..
weak acid or a weak base.