Unit 3 Biology Test

Materials are able to move across a cell membrane through one of two methods: active transport or passive transport. What is the difference between active transport and passive transport? A. Active transport requires the cell to expend energy, while passive transport does not. B. Passive transport is the only form of transport that requires the use of protein carriers. C. Active transport is the only form of transport that requires the use of protein carriers. D. Active transport requires the cell to form vesicles, while passive transport requires the use of membrane pumps.

A. Active transport requires the cell to expend energy, while passive transport does not.

_______ are the basic building blocks of all living organisms. A. Cells B. Organs C. Organ systems D. Tissues

A. Cells

The body's ability to maintain a relatively constant internal environment is called homeostasis. This stability can be challenged by reduced water or food intake. infectious organisms. extreme temperatures. elevated or depressed blood pH.

All are correct

Which of the following is an example of two or more body systems interacting to maintain homeostasis? When too much salt is consumed, it is filtered out of the blood by the kidneys and excreted. When body temperature is high, signals from the brain cause increased blood flow to the skin. When calcium levels in the blood are low, hormones cause calcium to be released from bones.

All of them

Which of the following best describes the process of diffusion? A. Diffusion is the movement of molecules from an area of higher concentration to one of lower concentration caused by an input of energy to the system. B. Diffusion is the movement of molecules from an area of lower concentration to one of higher concentration by random molecular motion. C. Diffusion is the movement of molecules from an area of higher concentration to one of lower concentration by random molecular motion. D. Diffusion is the movement of molecules from an area of lower concentration to one of higher concentration caused by an input of energy to the system.

C. Diffusion is the movement of molecules from an area of higher concentration to one of lower concentration by random molecular motion.

The levels of organizations in multicellular organisms are shown below, but they are not in the correct order. Arrange the levels of organization in order from simplest to most complex. Tissues, organs, organ systems, cells, and whole organisms

Cells, Tissues, Organs, Organ Systems, Whole Organisms

Cell theory states that A. cells are the basic unit of structure and function in living things. B. all living things are composed of cells. C. new cells are produced by existing cells. D. All of these answers are correct.

D. All of these answers are correct.

There are two main ways in which molecules are transported into and out of cells - active transport and passive transport. Which of the following statements is true of passive transport? A. Carrier proteins are sometimes used during passive transport. B. Endocytosis and exocytosis are two forms of passive transport. C. Energy, in the form of ATP, is essential for passive transport. D. Molecules move up a concentration gradient during passive transport.

A. Carrier proteins are sometimes used during passive transport.

Both eukaryotic cells and prokaryotic cells possess DNA and engage in genetic processes. Which of the following is true of their cellular genetics? A. Eukaryotic DNA is linear, whereas most prokaryotic DNA is circular. B. Prokaryotic DNA cannot be translated into proteins because of the lack of a nucleus. C. Eukaryotic cells generally require fewer genes to operate than prokaryotic cells. D. Eukaryotic and prokaryotic DNA use different genetic codes (i.e. nucleotides).

A. Eukaryotic DNA is linear, whereas most prokaryotic DNA is circular.

Which of the following are forms of cell regulation? enzyme activity osmosis diffusion A. I, II, and III B. I and II only C. I and III only D. II and III only

A. I, II, and III

Which of the following describes the fundamental difference between prokaryotic and eukaryotic cells? A. Prokaryotic cells do not have a true nucleus or membrane-bound organelles. B. Eukaryotic cells are only found in protists, bacteria, and viruses. C. Eukaryotic cells are the only type of cells that can possess a cell wall. D. Prokaryotic cells are all viruses and rely on the infection of a host cell to replicate.

A. Prokaryotic cells do not have a true nucleus or membrane-bound organelles.

Which of the following is true of prokaryotic cells? A. They function as individual organisms. B. They contain nuclei and other membrane-bound organelles. C. They tend to be large and complex in comparison to eukaryotic cells. D. They may be found in unicellular or multicellular organisms.

A. They function as individual organisms.

When a group of cells work together, such as in bones, muscles, or nerves, they are known as _______. A. a tissue B. an organelle C. an organ D. an organism

A. a tissue

Cells use __________ to take in large molecules or other cells. A. active transport by endocytosis B. passive transport by osmosis C. passive transport by diffusion D. active transport by carrier proteins

A. active transport by endocytosis

A group of tissues working together is _______. A. an organ B. a compound C. a cell D. an organelle

A. an organ

Multicellular organisms are composed of a variety of living structures that are formed when cells differentiate. How could the living structure pictured below be classified? A. cell B. organ C. organ system D. tissue

A. cell

The picture below shows a diagram of a single-celled organism known as a euglena. Which structure acts in a manner most similar to skin tissue in multicellular organisms? A. cell membrane B. chloroplast C. nucleus D. flagellum

A. cell membrane

The fluid mosaic model shown above describes the structure and function of A. cell membranes. B. chloroplasts. C. chromosomes. D. nuclei.

A. cell membranes.

Homeostasis is classified under which of the following? A. cell regulation B. transcription C. photosynthesis D. cell respiration

A. cell regulation

The diagrams below display different types of cells as viewed by a microscope under low magnification. These diagrams demonstrate how cells can be differentiated by their A. cell structures. B. modes of locomotion. C. means of replication. D. sizes and densities.

A. cell structures.

Which of the following is the only cell organelle that is capable of converting light energy into chemical energy? A. chloroplast B. vacuole C. endoplasmic reticulum D. mitochondrion

A. chloroplast

Examine the illustration below. Which of the following types of cellular transport is illustrated in the picture? A. exocytosis B. diffusion C. osmosis D. endocytosis

A. exocytosis

Membrane organelles known as _______ contain enzymes specialized to break down ingested materials, secretions, and wastes. A. lysosomes B. vacuoles C. ribosomes D. chloroplasts

A. lysosomes

When dry environmental conditions exist, guard cells close the openings in leaves to reduce the loss of water from the plant. This process is an example of a feedback mechanism that plants use in order to A. maintain homeostasis. B. absorb more solar energy. C. produce more chlorophyll. D. expend their resources.

A. maintain homeostasis.

The Golgi apparatus helps to maintain cellular homeostasis by A. modifying, sorting, and packaging proteins prior to transport. B. transforming absorbed light energy to manufacture carbohydrates. C. controlling which proteins are synthesized during the cell cycle. D. synthesizing ATP molecules from glucose during glycolysis.

A. modifying, sorting, and packaging proteins prior to transport.

Which of the following cell organelles contains instructions for making proteins? A. nucleus B. vacuole C. lysosome D. cell membrane

A. nucleus

An organ system is made up of A. organs that work together to perform a certain function. B. all of the tissues found in an individual organism. C. organisms that have similar behaviors and appearances. D. identical cells that perform the same function.

A. organs that work together to perform a certain function.

If the water concentration inside a cell is higher than the water concentration outside the cell, water flows out of the cell. This method of molecular transport is called A. osmosis. B. exocytosis. C. endocytosis. D. a sodium pump.

A. osmosis.

In carrying out normal activities, cells use oxygen and produce carbon dioxide. The concentration of oxygen is higher in the blood than inside the cell, so oxygen moves into the cell. Similarly, carbon dioxide moves out of the cell into the blood because the concentration of carbon dioxide inside the cell is greater than the concentration outside the cell. How are the small molecules of oxygen and carbon dioxide moving through the cell membrane? A. passive transport by diffusion B. active transport by endocytosis C. active transport by carrier proteins D. passive transport by osmosis

A. passive transport by diffusion

The life forms exhibiting the simplest cellular structure are _______. A. prokaryotes B. eukaryotes C. organelles D. proteins

A. prokaryotes

All multicellular organisms benefit from the organization of __________ into tissues, organs, and organ systems. A. specialized cells B. cellulose C. daughter cells D. organelles

A. specialized cells

There are many criteria that are used to define living things. Living things reproduce, grow, and develop. They respond to stimuli, use materials and energy, and evolve and adapt over time to their environment. What is another criteria used to define living things? A. All living things are able to move. B. All living things are made of cells. C. All living things are complex. D. All living things are intelligent.

B. All living things are made of cells.

Permeability is the condition of being capable of having materials flow into and out of a membrane. The permeability of a cell membrane is determined by how easily a molecule can diffuse across the membrane. Usually, only molecules that are fat-soluble can permeate across a cell membrane. Why is this the case? A. Water-soluble molecules are nonpolar. B. Cell membranes are composed of a lipid bilayer. C. Water-soluble molecules are too large. D. Cell membranes are composed of cytosol.

B. Cell membranes are composed of a lipid bilayer.

Homeostasis is the process through which an organism regulates its internal environment in order to maintain a stable and constant condition. An example of homeostasis is the regulation of the glucose sugar level in blood through the interaction of the hormones insulin and glucagon. What happens if the body is unable to maintain its blood glucose levels? A. New hormones are created to solve the problem. B. Diseases, such as diabetes and hypoglycemia, result. C. The body adapts to a different blood glucose level. D. This regulation is unnecessary to the viability of organisms.

B. Diseases, such as diabetes and hypoglycemia, result.

How do enzymes aid in cell regulation? A. Enzymes speed up reactions that stop life. B. Enzymes speed up reactions that help sustain life. C. Enzymes slow down reactions that help sustain life. D. Enzymes stop reactions that help sustain life.

B. Enzymes speed up reactions that help sustain life.

The diagram below shows a T4 bacteriophage. This virus consists of a single strand of DNA enclosed in a protein capsule. Is this virus considered a living organism? A. Yes; since the virus contains protein, it is a living organism. B. No; viruses are not considered to be living organisms. C. Yes; since the virus contains DNA, it is a living organism. D. No; living organisms must have two characteristics of life, and the T4 bacteriophage only has one.

B. No; viruses are not considered to be living organisms.

Cellular organelles have different structures. Mitochondria, for example, possess highly folded inner membranes in addition to their outer membranes. Vacuoles, on the other hand, are only surrounded by a single-layer membrane; they do not have an inner membrane. Why do cellular organelles have different structures? A. The structure of a cellular organelle mimics the appearance of the organism. B. The structures of cellular organelles are related to their functions. C. All of the organelles in a particular organism are identical, but organelles in different organisms are unique. D. Organelles that are less important to the cell have less sophisticated structures.

B. The structures of cellular organelles are related to their functions.

Mary sprays perfume in one corner of the classroom. Right after she sprays the perfume, the perfume molecules are concentrated in that corner of the room. Which of the following images shows how the perfume molecules will most likely look after ten minutes have passed, if the system is not affected by outside forces? W. X. Y. Z. A. X B. W C. Y D. Z

B. W (dots scattered)

Look at the diagram below. The yellow oval represents a cell with a semi-permeable membrane. The small, black dots represent molecules of water, and the larger, blue dots represent a solute such as sugar or salt. The membrane allows small molecules such as water to pass through, but it does not allow larger molecules such as solute to pass. What will happen to the substances in this diagram to bring the concentrations closer to equilibrium? A. Nothing will change because it is already in equilibrium. B. Water will flow out of the cell and into the surrounding environment. C. Water will flow into the cell from the surrounding environment. D. The solute will flow into the cell from the surrounding environment.

B. Water will flow out of the cell and into the surrounding environment.

All living things must possess certain characteristics. They are all composed of one or more cells. They can grow, reproduce, and pass their genes on to their offspring. They can respond and adapt to their environment, maintain homeostasis, and evolve. Given these characteristics of life, which of the following objects is considered a living organism? W. X. Y. Z. A. W B. X C. Z D. Y

B. Y. plant

In the human body, when the blood sugar level rises, a hormone known as insulin is released by the pancreas. This hormone speeds up the movement of sugar out of the blood, so the blood sugar level decreases and returns to equilibrium. This is an example of A. a learned behavior. B. a feedback mechanism. C. natural selection. D. gene expression.

B. a feedback mechanism.

Examine the following diagrams of plant cells. Each cell has been placed in a different solution. 1 2 3 The cell in diagram 3 has been placed in a solution that contains _______ the interior of the cell. A. water that is cooler than B. a lower concentration of water than C. a higher concentration of water than D. water that is warmer than

B. a lower concentration of water than

Osmosis is the diffusion of water across a selectively permeable membrane in which water moves from a solution containing a low concentration of solute to what kind of solution? A. a solution containing only the solute B. a solution containing a high concentration of solute C. a solution containing the same amount of solute D. a solution containing a high concentration of water

B. a solution containing a high concentration of solute

Materials essential to life processes move across a cell membrane through a variety of methods. What cell membrane structure allows water-soluble materials to be passively transported to the cytoplasm? A. endocytosis vesicles B. carrier proteins C. hydrophilic phospholipid tails D. Golgi complex vesicles

B. carrier proteins

Stem cells are undifferentiated cells that have the ability to continue to grow and divide in their nonspecialized state for long periods of time (e.g., months or years). Although the genes found within stem cells are the same, stem cells differentiate into unique cell types (e.g., muscle cells, nerve cells, etc.) due to A. random segregation and proliferation. B. different patterns in their gene expression. C. mutations in their genetic code. D. meiotic division and fertilization.

B. different patterns in their gene expression.

An organism's ability to maintain a stable internal environment in the midst of external environmental change is known as A. commensalism. B. homeostasis. C. metabolism. D. reproduction.

B. homeostasis.

Mitosis is the cellular reproduction process which produces two genetically identical daughter cells from one parent cell. Mitosis occurs all over our bodies, replacing dead cells and keeping tissues and organs functioning properly. Mitosis cannot occur until the genetic material inside of a cell has been copied. Where in the cell is this genetic material located? A. in the vacuole B. in the nucleus C. in the cell membrane D. in the Golgi complex

B. in the nucleus

Eukaryotic cells contain organelles that harvest energy from organic compounds to make ATP. ATP is the main form of energy used by cells. Which cell organelles are responsible for making most of the cell's ATP? A. chloroplasts B. mitochondria C. endoplasmic reticulum D. lysosomes

B. mitochondria

Which of the following organelles contains most of the cell's DNA? A. ribosome B. nucleus C. mitochondrion D. lysosome

B. nucleus

Within eukaryotic cells, there is an intricate network of _______ with unique functions. A. vacuoles B. organelles C. mitochondria D. chromosomes

B. organelles

Which of the following types of passive transport involves water molecules moving from a high concentration to a low concentration? A. filtration B. osmosis C. simple diffusion D. facilitated diffusion

B. osmosis

To meet cellular needs for food, water, energy, and waste removal, multicellular organisms have developed various _________ specializations, such as organs and organ systems. A. parental B. structural C. reproductive D. dietary

B. structural

The secretion of hormones is an example of a physiological feedback loop. When hormones are needed, they are secreted by glands. When the hormones are no longer needed, the glands are signaled to stop secreting the hormones until they are needed again. Thus, the basic function of a physiological feedback loop is A. to create substances. B. to regulate a process. C. to end a process. D. to destroy substances.

B. to regulate a process.

The following diagram shows the processes of fertilization and cell specialization. Which of the following statements is implied by the diagram? A. Specialized cells are produced immediately following fertilization, or the fusion of a sperm cell with an egg cell. B. Specialized cells, such as bone cells, skin cells, red blood cells, and muscle cells, cannot be produced from a single cell. C. Even though all the cells in an individual organism come from a single cell, they can specialize into different types of cells. D. Since all of the cells in an individual organism come from a single cell, they must all be identical.

C. Even though all the cells in an individual organism come from a single cell, they can specialize into different types of cells.

Which of the following organelles plays a role in the disposal of cellular waste and is responsible for processing, sorting, and modifying proteins? A. mitochondrian B. plasma membrane C. Golgi apparatus D. ribosome

C. Golgi apparatus

Which of the following is a function of the cell membrane of a cell? A. The transport of genetic material within the cytoplasm of the cell. B. The production of genetic material through DNA transcription. C. The transport of molecules into and out of the cell through osmosis and diffusion. D. The production of energy from food molecules using cellular respiration.

C. The transport of molecules into and out of the cell through osmosis and diffusion.

Plant and animals cells are both eukaryotic, and thus they are similar in many ways. However, plant cells have some organelles that are not present in animal cells. Which of the following organelles is not found in animal cells? A. a DNA-containing mitochondrion B. a membrane-covered endoplasmic reticulum C. a large vacuole D. a functioning Golgi complex

C. a large vacuole

Normal homeostatic conditions require potassium concentrations to be about 1000 times higher inside the cell than in the blood. What mechanism does a cell use to move these small potassium molecules into the cell against the concentration gradient? A. active transport by endocytosis B. passive transport by diffusion C. active transport by proteins D. passive transport by osmosis

C. active transport by proteins

Cells contain specialized parts, known as organelles, to perform specific tasks, such as waste disposal, protein building, and movement. Even though these basic cellular functions occur in all cells, A. the cells in unicellular organisms and all the cells in multicellular organisms must perform the same functions. B. all cells do not perform the same exact functions in unicellular organisms. C. all cells do not perform the same exact functions in multicellular organisms. D. the cellular components are not at all related to the overall function of the cell.

C. all cells do not perform the same exact functions in multicellular organisms.

All cells have a protective barrier that is formed of proteins and a lipid bilayer. What is the name of this barrier? A. cell wall B. phospholipid barrier C. cell membrane D. cytoplasm

C. cell membrane

What are the most basic building blocks of all organisms? A. muscles B. bones C. cells D. organs

C. cells

The ________ essentially aids in cellular homeostasis by providing the main transport mechanism for proteins within the cell. A. mitochondrion B. nucleus C. endoplasmic reticulum D. Golgi apparatus

C. endoplasmic reticulum

Which of the following organelles stores information and is considered the control center of the cell? A. mitochondrion B. Golgi complex C. nucleus D. endoplasmic reticulum

C. nucleus

Epinephrine is a hormone released from the adrenal gland of the body, most often in a stressful situation. It is known as the "fight-or-flight" hormone. One way that it causes a response in the body is to activate receptors on muscle cells. Where are these cellular receptors located? A. on the cell wall B. around the mitochondria C. on the cell membrane D. in the nucleus

C. on the cell membrane

Cells have particular structures that perform specific jobs. These structures are known as _______. A. tissues B. systems C. organelles D. organs

C. organelles

There are two main ways in which molecules are transported into and out of cells: active transport and passive transport. Which of the following is an example of active transport? A. osmosis B. filtration C. sodium-potassium pump D. plasmolysis

C. sodium-potassium pump

Cellular work is carried out by A. only nucleic acids, such as DNA and RNA. B. energy-deficient compounds. C. the different types of molecules that the cell assembles. D. organisms that have a symbiotic relationship with the cell.

C. the different types of molecules that the cell assembles.

Examine the following diagrams of plant cells. Each cell has been placed in a different solution. 1 2 3 The cell in diagram 2 has been placed in a solution that contains _______ the interior of the cell. A. water that is warmer than B. a lower concentration of water than C. the same concentration of water as D. water that is cooler than

C. the same concentration of water as

The cell membrane is a highly selective barrier that controls the movement of substances in and out of the cell. In fact, polar molecules are unable to go across unless A. they are enclosed in water-filled vesicles. B. they react with other substances to become nonpolar. C. they pass through channels in the cell membrane. D. they are broken down into smaller pieces.

C. they pass through channels in the cell membrane.

All living organisms use energy. They also grow and reproduce. What is another characteristic of all living organisms? A. All living organisms must consume food in order to acquire nutrition. B. All living organisms can produce glucose through photosynthesis. C. All living organisms consist of many cells with specialized organelles. D. All living organisms are composed of one or more cells.

D. All living organisms are composed of one or more cells.

Organisms must be able to adapt to a changing external and internal environment. An organism's ability to maintain a stable internal environment is known as homeostasis. How does a cell's membrane help an organism maintain homeostasis? A. Cell membranes directly control the temperature of the cell. B. Cell membranes protect the cell organelles from large doses of radiation. C. Cell membranes use a large portion of the cell's energy supply. D. Cell membranes control the substances that enter or leave cells.

D. Cell membranes control the substances that enter or leave cells.

Exocytosis is the process by which vesicles in the cytoplasm fuse with the cell membrane, releasing their contents into the cell's external environment. This is the form of transport used by a cell to dispose of large molecules. How does exocytosis help a cell maintain its homeostasis? A. Cells must regularly lose part of their membranes in order to maintain their homeostasis. B. In order to maintain their homeostasis, cells must release the exact same chemicals as they take in. C. In order to maintain their homeostasis, cells must release large molecules so that they can replicate themselves. D. Cells must dispose of wastes in order to maintain their homeostasis.

D. Cells must dispose of wastes in order to maintain their homeostasis.

How does the size of a eukaryotic organism normally compare to the size of a prokaryotic organism? A. Eukaryotes and prokaryotes are both usually very large organisms. B. Eukaryotes and prokaryotes are both usually very small organisms. C. Eukaryotes are usually much smaller than prokaryotes. D. Eukaryotes are usually much larger than prokaryotes.

D. Eukaryotes are usually much larger than prokaryotes.

How is homeostasis important to the survival of organisms? A. Homeostasis makes organisms grow bigger and taller. B. Homeostasis makes all organisms hibernate. C. Homeostasis helps organisms locate food. D. Homeostasis allows organisms to regulate their temperature.

D. Homeostasis allows organisms to regulate their temperature.

Which of the following is true about cells? A. In general, eukaryotic cells do not have a true nucleus or membrane-bound organelles, whereas prokaryotic cells contain both a nucleus and organelles enclosed by membranes. B. Both eukaryotic cells and prokaryotic cells always contain both a true nucleus that is well-defined and organelles that are separated from the cytoplasm by membranes. C. Neither prokaryotic cells nor eukaryotic cells ever contain both a true nucleus that is well-defined and organelles that are separated from the cytoplasm by membranes. D. In general, prokaryotic cells do not have a true nucleus or membrane-bound organelles, whereas eukaryotic cells contain both a nucleus and organelles enclosed by membranes.

D. In general, prokaryotic cells do not have a true nucleus or membrane-bound organelles, whereas eukaryotic cells contain both a nucleus and organelles enclosed by membranes.

_______ are RNA and protein complexes that are found in all cells. These complexes help cells during protein translation by joining amino acids together to form polypeptides. A. Chloroplasts B. Lysosomes C. Vacuoles D. Ribosomes

D. Ribosomes

In order to maintain homeostasis, human cells must have a higher concentration of sodium ions outside the cell than inside the cell. In addition, the concentration of potassium ions must be higher inside the cell than outside the cell. Which of the following forms of cellular transportation helps human cells maintain a relatively constant sodium and potassium concentration? A. endocytosis B. osmosis C. diffusion D. a cell membrane pump

D. a cell membrane pump

Prokaryotic and eukaryotic cells have many differences, but they also share some common features. Which of the following may be found in either type of cell? A. mitochondria B. Golgi bodies C. nuclei D. cell walls

D. cell walls

During heatstroke, the body can't dispose of excess heat. As a result, the homeostatic balance is disturbed, and internal body temperatures can reach as much as 110°. Heatstroke is dangerous to people primarily because A. blood pressure becomes too low. B. it causes pneumonia. C. blood vessels may rupture. D. cells can't function properly at high temperatures.

D. cells can't function properly at high temperatures.

The cell membrane, or plasma membrane, is made up of a lipid bilayer in which hydrophilic heads face outward and hydrophobic tails face inward. This arrangement within the cell membrane allows it to A. keep out all viral and bacterial infections. B. fuse with ribosomes during DNA replication. C. absorb water from the cytoplasm whenever necessary. D. control the movement of substances in and out of the cell.

D. control the movement of substances in and out of the cell.

Homeostasis is the regulation of metabolic processes within an organism in order to maintain the stable internal conditions required for life. The human respiratory system includes the nose, the larynx, and the lungs. This body system helps maintain homeostasis by A. transporting oxygen to other organ systems. B. regulating hormone levels in the body. C. removing solid waste from the body. D. enabling gas exchange in the body.

D. enabling gas exchange in the body.

Which of the following types of passive transport involves the movement of molecules via special transport proteins? A. filtration B. simple diffusion C. osmosis D. facilitated diffusion

D. facilitated diffusion

Which of the following types of passive transport involves the movement of water and solute molecules due to hydrostatic pressure? A. simple diffusion B. facilitated diffusion C. osmosis D. filtration

D. filtration

Aquatic mammals, such as seals and dolphins, are able to stay submerged in water for long periods of time because of the mammalian diving reflex. When submerged in cold water, and while the mammal is holding its breath, receptors in the nasal cavity and other areas of the face relay a message to the brain that causes blood to only circulate between the heart and the brain. This allows oxygen to be conserved and increases the time aquatic mammals can stay underwater between breaths. The mammalian diving reflex is an example of what process? A. genetic viability B. autoimmune response C. respiration D. homeostasis

D. homeostasis

Emphysema is a health condition in which the lungs can no longer expel carbon dioxide normally. As a result, a person who has emphysema may have high blood acidity levels. The body process that would attempt to return the blood pH to normal so that cells could function properly is called _______. A. adaptation B. active transport C. acidosis D. homeostasis

D. homeostasis

All living organisms share many characteristics necessary for life. For example, all organisms, including both prokaryotic and eukaryotic, A. can sexually reproduce to produce unique offspring. B. can use abiotic factors to make their own food. C. have cells arranged into complex organ structures. D. must obtain and use energy for life processes.

D. must obtain and use energy for life processes.

Cells can function A. in rapidly changing temperatures and pHs. B. in a wide range of pHs and temperatures. C. at any temperature and pH. D. only in a narrow range of temperature and pH.

D. only in a narrow range of temperature and pH.

Multicellular organisms are composed of a variety of living structures that are formed when cells differentiate. How could the living structure pictured below be classified? (A Heart) A. cell B. tissue C. organism D. organ

D. organ

Multicellular organisms are composed of a variety of living structures that are formed when cells differentiate. How could the living structure pictured below be classified? A. tissue B. cell C. organism D. organ system

D. organ system

What is the single most abundant compound in living organisms? A. carbon B. sugar C. fat D. water

D. water

Which of the following describes a function of the endoplasmic reticulum within a cell? intracellular transport lipid synthesis DNA storage protein modification

Intracellular transport, lipid synthesis, and protein modification

The components of the human body, from organ systems to cell organelles, interact to maintain a balanced internal environment. To successfully accomplish this task, organisms possess many different receptors that detect deviations in the body's internal state and initiate corrective actions. In which of the following ways does the body respond to an increase in skeletal muscle cell activity? by increasing the respiratory rate by converting white bloods cells to red blood cells by increasing the heart rate by producing less hemoglobin

by increasing the respiratory rate, by increasing the heart rate

Diffusion is the spontaneous movement of a substance from an area of - concentration to an area of - concentration.

higher, lower