BIO253 Chapter 3

Active transport processes require cellular energy, usually in the form of ATP, while passive transport processes don't require cellular energy. (true or false)

true- the source of energy in active processes is cellular energy while in most passive processes the source of energy is molecular motion.

What is the term used for membranous sacs that store or transport substances within a cell or between cells?

vesicle

Membranous sacs containing substances that were produced in the cell, such as neurotransmitters or hormones, are called

vesicles

Exocytosis uses ______ to move substances ______ the cell.

vesicles; out of

Osmosis is the diffusion of ______ through a selectively permeable membrane.

water

Which conditions are necessary for the diffusion of a substance to occur across a membrane?

-a concentration gradient -membrane permeability

Which transport mechanisms are classified as passive mechanisms?

-diffusion -osmosis -filtration -facilitated diffusion

Which transport mechanisms are classified as active mechanisms?

-exocytosis -endocytosis -active transport

What are the functions of the cell membrane?

-it is the site of signal transduction -it is a selectively permeable barrier

Place the stages of mitosis in the correct order with the beginning of the process at the top.

-prophase -metaphase -anaphase -telophase

Which factors would decrease the rate of diffusion?

-shallower concentration gradient -longer distance (smaller difference in concentrations) -lower temperature

Which factors would increase the rate of diffusion?

-steeper concentration gradient -shorter distance (greater difference in concentrations) -higher temperature

What occurs during metaphase?

Chromosomes line up in the middle of the cell

The nucleus contains ______, which directs all cell activities.

DNA

The type of active transport mechanism in which large molecules or particles are conveyed by a vesicle into the cell is known as

Endocytosis or Phagocytosis

______ are two identical structures, formed as a result of DNA replication and temporarily attached by a region on each called a centromere.

Sister chromatids- the word "sister" is used to describe duplicates and the term used to indicate a duplicated chromosome is "chromatid".

What are microvilli?

Tiny extensions of the cell membrane that absorb substances.

Why shouldn't a patient receive an intravenous solution of pure water?

Water is hypotonic to blood cells' cytosol, so these cells would swell and burst.

In active transport, substances are transported from regions of low concentration to regions of high concentration by ______.

a pump

A carrier molecule (sometimes called a pump) transports substances from regions of lower concentration to regions of higher concentration in _______ transport.

active

Differentiated cells in the body have ______ of the available genetic instructions.

all

Specialized cells in the body have ______ of the genes and express ______ of them.

all; some

Which phase of mitosis is illustrated in this figure?

anaphase- the image represents anaphase, which is distinguished by a separation of the sister chromatids. In metaphase, only one band of chromosomes can be seen as they all line up in the middle. In telophase, the mitotic spindle, as well as the genetic material would be less distinguishable. In prophase, the chromosomes would not show an orderly arrangement.

The term that describes the series of changes that a cell undergoes, including its growth and division, is the

cell cycle

During anaphase ______.

centromeres separate, chromosomes move to opposite ends of the cell

Within the cytoplasm, what is the clear liquid in which organelles are suspended?

cytosol- the question asks for the clear liquid found in the cytoplasm, which is called cytosol. Recall that cytoplasm is composed of cytosol, organelles, and the cytoskeleton

The process that occurs due to the random movement of atoms, molecules, or ions in air or liquid, from areas of higher concentration to areas of lower concentration, is known as

diffusion

The random movement of atoms, molecules, or ions in air or liquid, from areas of higher concentration to areas of lower concentration, is called simple

diffusion

A substance moving from an area of high concentration to an area in which it has a low concentration is moving ______ the concentration gradient.

down

In osmosis, water diffuses through a semipermeable membrane ______ its concentration gradient.

down- water moves via osmosis, which does not require energy. For substances to move against (or up) a gradient would be moving substances from areas of low to areas of high concentration and requires energy.

Unlike passive transport mechanisms, active transport requires the input of cellular

energy or ATP

Diffusional ______ occurs when the concentration of a given substance becomes uniform throughout a solution and there is no further net movement of molecules throughout the solution.

equilibrium

The process by which vesicles carrying substances made in the cell fuse with the cell membrane and release those substances outside the cell is called ______.

exocytosis

Vesicles fuse with the cell membrane, releasing their contents outside of the cell, during the process of

exocytosis

A passive process called ______ involves substances moving down their concentration gradient through protein channels or carriers in the cell membrane.

facilitated diffusion

The passive transport mechanism in which molecules or ions move via carrier or channel proteins from a region of higher concentration to a region of lower concentration is called

facilitated diffusion

Ions that use specific protein channels in the membrane use a process called ______ to move down their concentration gradient across the plasma membrane.

facilitated diffusion- while some ions are actively transported, the questions stated "down their concentration gradient", which means passive transport

A type of passive movement through the cell membrane is ______ while a type of active movement is ______.

facilitated diffusion; exocytosis

Neither facilitated diffusion nor simple diffusion requires a protein channel or carrier to move molecules across the membrane. (true or false)

false- facilitated diffusion requires a protein channel to move molecules across the membrane

When molecules move down a concentration gradient, it means that there is a net movement of particles from a region of lower concentration to a region of higher concentration (true or false)

false- molecules move down a concentration gradient when they move from a region of higher concentration to a region of lower concentration.

A passive transport process that forces molecules through membranes by exerting pressure is called ______.

filtration

The passive transport mechanism in which small solutes are forced through a membrane by hydrostatic pressure is known as

filtration

Solutions A and B are separated by a semipermeable membrane. Solution A has more solutes than solution B. In which direction will osmosis occur?

from B to A- osmosis is the movement of water, and water moves toward a higher concentration of solutes

Which of the following would increase the diffusion rate?

higher temperature

In filtration, a solution is pushed through a membrane by a force called ______. This is a(n) _____ transport mechanism.

hydrostatic pressure; passive

When cells are put into a(n) ______ solution, there is a net movement of water out of the cells by osmosis and the cells shrink.

hypertonic

When cells are put into a(n)______ solution, cells gain water by osmosis and swell or possibly even burst.

hypotonic

The active period of the cell cycle, during which a cell grows, its DNA replicates, and organelles are formed, is called _________. It terminates when the cell begins mitosis.

interphase

The phase that begins after cytokinesis and ends at prophase is called ______.

interphase

Endocytosis takes particles ______ the cell by using ______.

into; vesicles- endocytosis requires energy and utilizes vesicles to take particles that are too large to enter a cell by other means.

A solution that has the same osmotic pressure as the intracellular and extracellular body fluids is called a(n) _______ solution.

isotonic or isosmotic

Which type of solution has the same osmotic pressure as the extracellular fluid in the body?

isotonic solution

Active transport is a process that moves particles through a membrane from a region of ______ concentration to a region of ______ concentration.

low; higher- active transport moves substances against a concentration gradient.

Spindle fibers attach to centromeres, chromosomes move along spindle fibers and are aligned at the equator of the cell during the phase of mitosis called

metaphase

Which phase of mitosis is represented in this image?

metaphase

Which chromosomal division process occurs in somatic cells and produces two daughter cells from an original cell?

mitosis

The diffusion of water through a selectively permeable membrane is called ______.

osmosis

Both simple diffusion and facilitated diffusion are ______ transport mechanisms that move molecules ______ a concentration gradient.

passive; down- simple diffusion always goes down a gradient, like the passive rolling of a ball down a hill; simple and facilitate diffusion are both passive processes

Diffusion of a substance across a membrane can happen only if the membrane is ______ to that substance and a concentration gradient ______ across the membrane

permeable; exists

The process by which solid particles enter cells in vesicles made from a portion of the cell membrane is called ______.

phagocytosis

The type of endocytosis in which a cell membrane engulfs solid particles from its surroundings is called

phagocytosis

During ______, chromatin condenses into visible chromosomes, centrioles move to opposite sides of the cell, spindle fibers form as the centrioles move apart, and the nuclear envelope and nucleolus disperse.

prophase

The phase of mitosis during which the chromosomes first become visible due to the tight coiling of DNA is _________.

prophase

When cells are placed into a hypertonic solution, they will ______.

shrink- hypertonic solutions have a higher osmotic pressure (more solutes). Water would therefore move out of the cell and the cell would shrink.

As a result of DNA replication during interphase, each chromosome consists of two identical structures called

sister chromatids

Phagocytosis is the process by which cells engulf ______ from the extracellular fluid.

solid particles

Mitosis occurs in ______ cells and produces ______ daughter cells.

somatic; two

The stage of mitosis in which chromosomes uncoil to become thin chromatin fibers and the nuclear envelope reforms is

telophase

What is the name of the stage of mitosis in which the nuclear envelope forms, the nucleolus appears, and the microtubules disassemble?

telophase

Which phase of mitosis is illustrated in this image?

telophase- this image represents telophase. The mitotic spindle is disappearing and chromosomes are decondensing.