If a tRNA had an AGC anticodon, it could attach to a(n) ________ mRNA codon.

If a tRNA had an AGC anticodon, it could attach to a(n) ________ mRNA codon.  A) AUG B) UCG C) TCG D) UGA Answer: ...

Some hormones enter cells via ________.

Some hormones enter cells via ________.  A) exocytosis B) endocytosis C) pinocytosis D) receptor-mediated endocytosis Answer: ...

Crenation is likely to occur in ________.

Crenation is likely to occur in ________.  A) blood cells in an isotonic solution B) blood cells in a hypotonic solution C) blood cells in a...

Extracellular matrix is ________.

Extracellular matrix is ________.  A) composed of strands of actin protein B) the most abundant extracellular material C) a type of impermeable...

A gene can best be defined as ________.

A gene can best be defined as ________.  A) a three-base triplet that specifies a particular amino acid B) noncoding segments of DNA up to 100,000...

The functions of centrioles include ________.

The functions of centrioles include ________.  A) organizing the mitotic spindle in cell division B) providing a whiplike beating motion to...

The endomembrane system is ________.

The endomembrane system is ________.  A) a system by which cells are riveted together by desmosomes B) an interactive system of organelles whose...

Lysosomes ________.

Lysosomes ________.  A) are always used for the cell to "commit suicide" B) contain acid hydrolases that are potentially dangerous to the cell C)...

The main component of the cytosol is ________.

The main component of the cytosol is ________.  A) proteins B) sugars C) salts D) water Answer: ...

Which of the following statements is most correct regarding the intracellular chemical signals known as "second messengers"?

Which of the following statements is most correct regarding the intracellular chemical signals known as "second messengers"?  A) Second messengers...

Which of the following is a principle of the fluid mosaic model of cell membrane structure?

Which of the following is a principle of the fluid mosaic model of cell membrane structure?  A) Phospholipids form a bilayer that is largely...

Cells are composed mainly of ________.

Cells are composed mainly of ________.  A) carbon, potassium, sodium, nitrogen B) carbon, sodium, nitrogen, calcium C) calcium, oxygen, sodium,...

Which of the following is a concept of the cell theory?

Which of the following is a concept of the cell theory?  A) Simple cells can arise spontaneously from rotting vegetation. B) A cell is the basic...

In the maintenance of the cell resting membrane potential ________.

In the maintenance of the cell resting membrane potential ________.  A) extracellular sodium levels are high B) cells are more permeable to...

Which statement is the most correct regarding transcription/translation?

Which statement is the most correct regarding transcription/translation?  A) The nucleotide sequence in a mRNA codon is an exact copy of the...

DNA replication ________.

DNA replication ________.  A) can also be called mitosis B) is spontaneous, not requiring enzyme action C) takes place during interphase of the...

Peroxisomes ________.

Peroxisomes ________.  A) also called microbodies, contain acid hydrolases B) are able to detoxify substances by enzymatic action C) function...

Ribosomes, endoplasmic reticulum, and the Golgi apparatus functionally act in sequence to synthesize and modify proteins for secretory use (export) only, never for use by the cell. This statement is ________.

Ribosomes, endoplasmic reticulum, and the Golgi apparatus functionally act in sequence to synthesize and modify proteins for secretory use (export)...

Mitochondria ________.

Mitochondria ________.  A) are always the same shape B) are single-membrane structures involved in the breakdown of ATP C) contain some of the...

Enzymes called _________ destroy the cell's DNA and cytoskeleton, producing a quick death to the cell.

Enzymes called _________ destroy the cell's DNA and cytoskeleton, producing a quick death to the cell.  A) ubiquitins B) cyclins C) caspases D)...

Passive membrane transport processes include ________.

Passive membrane transport processes include ________.  A) movement of a substance down its concentration gradient B) movement of water from...

Phospholipids ________.

Phospholipids ________.  A) are exclusively hydrophilic molecules B) contain polar tails and nonpolar head groups C) are both hydrophilic and...

Which of the following is true regarding cells in humans?

Which of the following is true regarding cells in humans?  A) Organelles are independent life forms. B) Maximum cell diameter is limited to...

If the nucleotide or base sequence of the DNA strand used as a template for messenger RNA synthesis is ACGTT, then the sequence of bases in the corresponding mRNA would be ________.

If the nucleotide or base sequence of the DNA strand used as a template for messenger RNA synthesis is ACGTT, then the sequence of bases in the corresponding...

Hyperplasia means __________.

Hyperplasia means __________.  A) programmed cell death B) abnormalities in cell structure C) a condition where the cell overproduces "cell glue" D)...

Which of these is an inclusion, not an organelle?

Which of these is an inclusion, not an organelle?  A) melanin B) lysosome C) microtubule D) cilia Answer: ...

The electron microscope has revealed that one of the components within the cell consists of microtubules arranged to form a hollow tube. This structure is ________.

The electron microscope has revealed that one of the components within the cell consists of microtubules arranged to form a hollow tube. This structure...

Mitosis ________.

Mitosis ________.  A) is the formation of sex cells B) produces nucleus replication C) creates diversity in genetic potential D) always results...

Which of the following would not be a constituent of a plasma membrane?

Which of the following would not be a constituent of a plasma membrane?  A) glycolipids B) messenger RNA C) glycoproteins D) phospholipids Answer:...

Which of the following statements is correct regarding RNA?

Which of the following statements is correct regarding RNA?  A) Messenger RNA, transfer RNA, and ribosomal RNA play a role in protein synthesis. B)...

Which of the following is a function of a plasma membrane protein?

Which of the following is a function of a plasma membrane protein?  A) circulating antibody B) molecular transport through the membrane C) forms...

Riboswitches are folded RNAs that act as switches to turn protein synthesis on or off in response to _________.

Riboswitches are folded RNAs that act as switches to turn protein synthesis on or off in response to _________.  A) changes in the environment B)...

Once solid material is phagocytized and taken into a vacuole, which of the following statements best describes what happens?

Once solid material is phagocytized and taken into a vacuole, which of the following statements best describes what happens?  A) A ribosome...

Which of the following is not a subcellular structure?

Which of the following is not a subcellular structure?  A) intercellular material B) membranes C) cytoplasm D) organelles Answer: ...

If cells are placed in a hypertonic solution containing a solute to which the membrane is impermeable, what could happen?

If cells are placed in a hypertonic solution containing a solute to which the membrane is impermeable, what could happen?  A) The cells will...

Cell junctions that promote the coordinated activity of cells by physically binding them together into a cell community include all of the following except ________.

Cell junctions that promote the coordinated activity of cells by physically binding them together into a cell community include all of the following...

Which of the following statements is correct regarding diffusion?

Which of the following statements is correct regarding diffusion?  A) The rate of diffusion is independent of temperature. B) The greater the...

Which structures are fingerlike projections that greatly increase the absorbing surface of cells?

Which structures are fingerlike projections that greatly increase the absorbing surface of cells?  A) stereocilia B) microvilli C) cilia D) flagella Answer:...

Which of these is not a function of the plasma membrane?

Which of these is not a function of the plasma membrane?  A) It is selectively permeable. B) It prevents potassium ions from leaking out and...

The plasma membrane is ________.

The plasma membrane is ________.  A) a single-layered membrane that surrounds the nucleus of the cell B) a double layer of protein enclosing...

A red blood cell placed in pure water would ________.

A red blood cell placed in pure water would ________.  A) shrink B) swell initially, then shrink as equilibrium is reached C) neither shrink...

The RNA responsible for bringing the amino acids to the "factory" site for protein formation is the ________.

The RNA responsible for bringing the amino acids to the "factory" site for protein formation is the ________.  A) rRNA B) mRNA C) tRNA D) ssRNA Answer:...

In certain kinds of muscle cells, calcium ions are stored ________.

In certain kinds of muscle cells, calcium ions are stored ________.  A) in the smooth ER B) in the rough ER C) in both smooth and rough ER D)...

Transcytosis is ________.

Transcytosis is ________.  A) combining an endosome with a lysosome and degrading or releasing the contents B) transporting an endosome from...

Which of the following is true regarding the generation of a membrane potential?

Which of the following is true regarding the generation of a membrane potential?  A) Both potassium and sodium ions can "leak" through the cell...

The _______ hypothesis states that no difference exists due to the variable under investigation.

The _______ hypothesis states that no difference exists due to the variable under investigation. Answer: nu...

Scientific investigations are based above all on the processes of _______ and _______.

Scientific investigations are based above all on the processes of _______ and _______. Answer: observation; experimentati...

Fungi and animals both belong to the _______ domain, and their cell structure is _______.

Fungi and animals both belong to the _______ domain, and their cell structure is _______. Answer: Eukarya; multicellular ...

Multicellular organisms that are photosynthetic belong to the kingdom _______.

Multicellular organisms that are photosynthetic belong to the kingdom _______. Answer: Plant...

A _______ tree shows the evolutionary relationships among species.

A _______ tree shows the evolutionary relationships among species. Answer: phylogenet...

A Pacific tree frog has the scientific nomenclature of Hyla regilla. This particular tree frog belongs to the genus _______.

A Pacific tree frog has the scientific nomenclature of Hyla regilla. This particular tree frog belongs to the genus _______. Answer: Hy...

Scientists who study evolution and classification of life's diverse organisms are called _______.

Scientists who study evolution and classification of life's diverse organisms are called _______. Answer: systematis...

There are three domains used to categorize life forms that have evolved separately for about a billion years: _______, _______, and _______.

There are three domains used to categorize life forms that have evolved separately for about a billion years: _______, _______, and _______. Answer:...

Single-celled organisms that lack discrete intracellular compartments belong to the two kingdoms: _______ and _______.

Single-celled organisms that lack discrete intracellular compartments belong to the two kingdoms: _______ and _______. Answer: Archaea; Bacter...

In contrast to eukaryotic cells, prokaryotes lack discrete _______ compartments.

In contrast to eukaryotic cells, prokaryotes lack discrete _______ compartments. Answer: intracellul...

Some organelles in eukaryotes can be described as _______ within a cell.

Some organelles in eukaryotes can be described as _______ within a cell. Answer: cel...

About _______ years ago, prokaryotes acquired the ability to photosynthesize.

About _______ years ago, prokaryotes acquired the ability to photosynthesize. Answer: 2.7 billi...

The ability to use energy from sunlight to synthesize complex molecules is known as _______.

The ability to use energy from sunlight to synthesize complex molecules is known as _______. Answer: photosynthes...

Fatlike molecules were the critical ingredient in the enclosure of biological molecules in _______ because these molecules are not _______ in water and tend to form membrane-like _______.

Fatlike molecules were the critical ingredient in the enclosure of biological molecules in _______ because these molecules are not _______ in water...

Currently, scientists agree with the estimate that life first appeared approximately _______ years ago.

Currently, scientists agree with the estimate that life first appeared approximately _______ years ago. Answer: 4 billi...

The total chemical activity of a living organism is called its _______.

The total chemical activity of a living organism is called its _______. Answer: metaboli...

____ are structural, physiological, or behavioral traits that enhance an organism's chance of survival and reproduction in its environment.

____ are structural, physiological, or behavioral traits that enhance an organism's chance of survival and reproduction in its environment. Answer:...

Most living organisms consist of one or more _______, have changed or _______ over time, and can regulate their _______ environment.

Most living organisms consist of one or more _______, have changed or _______ over time, and can regulate their _______ environment. Answer: cells;...

Overfishing of the western bluefin tuna in the Gulf of Mexico breeding ground resulted in a serious decline in the population. Fishing quotas were established in the Gulf of Mexico to allow the endangered population to recover. Why did this policy fail to achieve the desired result?

Overfishing of the western bluefin tuna in the Gulf of Mexico breeding ground resulted in a serious decline in the population. Fishing quotas were established...

Which of the following questions cannot be answered by means of the hypothetico-deductive method?

Which of the following questions cannot be answered by means of the hypothetico-deductive method? a. Are bees more attracted to red roses than to...

Which of the following statements about the experiments of Tyrone Hayes on abnormalities of male frog sex organs is correct?

Which of the following statements about the experiments of Tyrone Hayes on abnormalities of male frog sex organs is correct? a. In a set of controlled...

Which of the following statements represents a scientific point of view?

Which of the following statements represents a scientific point of view? a. Earth was created by a supernatural force. b. The positions of the sun,...

Comparative experiments are designed to answer questions that require

Comparative experiments are designed to answer questions that require a. observation and comparison rather than controlled variables. b. experimental...

Which of the following statements is false?

Which of the following statements is false? a. Statistical methods are applied to data in order to calculate the likelihood that the null hypothesis...

The advantage of controlled experiments is that

The advantage of controlled experiments is that a. all variables are held constant except for one. b. the hypothesis is proven right. c. patterns...

Which of the following statements about the scientific method is correct?

Which of the following statements about the scientific method is correct? a. Deductive logic is used to make predictions from a hypothesis. b. The...

Which of the following is not a feature of scientific hypotheses?

Which of the following is not a feature of scientific hypotheses? a. They are unable to be falsified. b. They make predictions. c. They are based...

The main purpose of any single experiment is to

The main purpose of any single experiment is to a. obtain accurate quantitative measurements. b. prove unambiguously that a particular hypothesis...

After observing that fish live in clean water but not in polluted water, researchers state that "polluted water kills fish." This statement is an example of

After observing that fish live in clean water but not in polluted water, researchers state that "polluted water kills fish." This statement is an example...

Which of the following is not a major step in the hypothetico-deductive method?

Which of the following is not a major step in the hypothetico-deductive method? a. Controlling an environment b. Making an observation c. Forming...

Which of the following can result from a scientific investigation?

Which of the following can result from a scientific investigation? a. Proof of the hypothesis b. Refinement of the experimental design c. Formulation...

The branching patterns of the evolutionary tree of life are based on a rich array of evidence from

The branching patterns of the evolutionary tree of life are based on a rich array of evidence from a. fossils. b. molecular evidence. c. metabolic...

A phylogenetic tree

A phylogenetic tree a. shows evolutionary relationships. b. relies on evidence from fossils, metabolic processes, and molecular analyses of genomes. c....

The domain Eukarya includes all of the following except

The domain Eukarya includes all of the following except a. Archaea. b. the kingdom Plantae. c. the kingdom Fungi. d. the kingdom Animalia. e. protists Answer:...

Scientists group species on an evolutionary tree that is based on

Scientists group species on an evolutionary tree that is based on a. the fossil record. b. physical structures. c. genomic sequencing. d. All of...

Biologists have organized the diversity of life into three domains based largely on

Biologists have organized the diversity of life into three domains based largely on a. physical similarities. b. ecological niches. c. chronological...

Plants are

Plants are a. eukaryotic multicellular autotrophs. b. eukaryotic unicellular autotrophs. c. eukaryotic multicellular heterotrophs. d. prokaryotic...

Plants, fungi, and animals have evolved from

Plants, fungi, and animals have evolved from a. protists. b. endosymbiotic bacteria. c. Archaea. d. cyanobacteria. e. inorganic molecules. Answer:...

Ozone is important to life on Earth because it

Ozone is important to life on Earth because it a. is toxic to all forms of life. b. can be used in place of oxygen. c. blocks much ultraviolet radiation. d....

The chemical formula for ozone is

The chemical formula for ozone is a. O. b. O2. c. H2O2. d. O3. e. None of the above Answer: ...

A prerequisite for the survival of life on land was the accumulation of

A prerequisite for the survival of life on land was the accumulation of a. O2 in the atmosphere. b. CO2 in the atmosphere. c. water vapor in the...

The initial accumulation of oxygen in the atmosphere was the result of photosynthesis from an organism most like modern

The initial accumulation of oxygen in the atmosphere was the result of photosynthesis from an organism most like modern a. cyanobacteria. b. algae. c....

Metabolism is

Metabolism is a. the consumption of energy only. b. the release of energy only. c. all conversions of matter and energy taking place in an organism. d....

Scientists estimate that for more than _______ years after cells originated, all organisms consisted of one cell.

Scientists estimate that for more than _______ years after cells originated, all organisms consisted of one cell. a. 2,500 b. 250,000 c. 2.5 million d....

Earth is approximately _______ years old.

Earth is approximately _______ years old. a. 4-5 billion b. 4-5 trillion c. 4-5 million d. 6,000 e. 40-50 trillion Answer: ...

A gene controlling human skin color was discovered in experiments with

A gene controlling human skin color was discovered in experiments with a. fruit flies. b. zebrafish. c. roundworms. d. mustard plants. e. sea urchins. Answer:...

Yeasts can be used to study human cancer because yeasts and humans

Yeasts can be used to study human cancer because yeasts and humans a. share a genetic code. b. are both prokaryotes. c. have exactly the same genome. d....

Which of the following represents a correct ordering of the levels of complexity at which life is studied, from most simple to most complex?

Which of the following represents a correct ordering of the levels of complexity at which life is studied, from most simple to most complex? a. Cell,...

All living organisms acquire _______ from their environment.

All living organisms acquire _______ from their environment. a. food b. nutrients c. sunlight d. heterotrophic nutrition e. autotrophic nutrition Answer:...

Which of the following statements is true?

Which of the following statements is true? a. The diversity of life has depended on similar environments and ecological communities throughout the...

A key point in Darwin's explanation of evolution is that

A key point in Darwin's explanation of evolution is that a. the biological structures most likely to be inherited are those that have become best...

Based on the large numbers of offspring produced by many organisms, Darwin proposed that mortality was high and only a few individuals survived to reproduce. He referred to the differential reproductive success of individuals with particular variations as

Based on the large numbers of offspring produced by many organisms, Darwin proposed that mortality was high and only a few individuals survived to reproduce....

A species consists of

A species consists of a. all the organisms that live together in a particular area. b. morphologically similar organisms that cannot interbreed. c....

Darwin noted that all populations have _______ potential to grow, but that in nature most populations _______ over time.

Darwin noted that all populations have _______ potential to grow, but that in nature most populations _______ over time. a. limited; are stable b....

A cell

A cell a. can be composed of many types of tissues. b. is found only in plants and animals. c. is the smallest entity studied by biologists. d. may...

The basic structural and physiological unit of all living organisms is the

The basic structural and physiological unit of all living organisms is the a. aggregate. b. organelle. c. organism. d. membrane. e. cell. Answer:...

Which of the following was the most significant limiting factor in human population growth in the 20th century?

Which of the following was the most significant limiting factor in human population growth in the 20th century? A) clean water B)non-HIV disease C)HIV D)genocide E)famine Answer:...

Which of the following areas of study focuses on the exchange of energy, organisms, and materials between ecosystems?

Which of the following areas of study focuses on the exchange of energy, organisms, and materials between ecosystems? A)organismal ecology B)landscape...