Chapter 3 Flash Cards

Which of the following statements is correct regarding net diffusion?

• The rate is independent of temperature.

• The greater the concentration gradient, the faster the rate.

• Molecular weight of a substance does not affect the rate.

• The lower the temperature, the faster the rate.

In a tissue type that undergoes a relatively great deal of mechanical stress, like the tissue that lines the intestine, you would expect to see an abundance of  between the individual cells of the tissue.

• gap junctions

• desmosomes

• connexons

• tight junctions

Doomed proteins are marked for destruction when  proteins are attached to them.

• ubiquitin

• ribosome

• polymerase

• transfer

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

• circulating antibody

• molecular transport through the membrane

• forms a lipid bilayer

• oxygen transport

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

• glycolipids

• messenger R N A

• glycoproteins

• phospholipids

Mitosis .

• is the formation of sex cells

• is division of the genetic material within the nucleus

• creates diversity in genetic potential

• is always a part of the cell cycle

The electron microscope has revealed that one of the components within the cell consists of pinwheel array of 9 triplets of microtubules arranged to form a hollow tube. This structure is a .

• centrosome

• centriole

• chromosome

• ribosome

Which of these is an inclusion, not an organelle?

• melanin

• lysosome

• microtubule

• cilia

Which of the following is NOT a factor that binds cells together?

• glycoproteins in the glycocalyx

• glycolipids in the glycocalyx

• wavy contours of the membranes of adjacent cells

• special membrane junctions

If the nucleotide or base sequence of the D N A strand used as a template for messenger R N A synthesis is A C G T T, then what would be the sequence of bases in the corresponding m R N A?

• T G C A A

• A C G T T

• U G C A A

• G U A C C

Which transport process is the main mechanism for the movement of most macromolecules by body cells?

• phagocytosis

• pinocytosis

• receptor-mediated endocytosis

• secondary active transport

Which of the following is NOT a function of the smooth endoplasmic reticulum?

• lipid metabolism and cholesterol synthesis

• steroid-based hormone synthesis

• breakdown of stored glycogen to form free glucose

• protein synthesis in conjunction with ribosomes

Mitochondria .

• contain digestive enzymes called acid hydrolyses

• are single-membrane structures involved in the breakdown of A T P

• contain some of the D N A and R N A code necessary for their own function

• synthesize proteins for use outside the cell

Peroxisomes .

• are functionally the same as lysosomes

• are able to detoxify substances by enzymatic action

• function to digest particles ingested by endocytosis

• sometimes function as secretory vesicles

Which of the following is NOT a function of lysosomes?

• digesting particles taken in by endocytosis

• degrading worn-out or nonfunctional organelles

• help in the formation of plasma membranes

• breaking down bone to release calcium ions into the blood

In which stage of mitosis do the identical sets of chromosomes line up along the midline or equator of the cell?

• prophase

• metaphase

• anaphase

• telophase

Which organelle is responsible for processing and packaging proteins destined for export from the cell?

• endoplasmic reticulum

• Golgi apparatus

• lysosomes

• peroxisomes

The functions of centrioles include .

• organizing the mitotic spindle in cell division

• providing a whiplike beating motion to move substances along cell surfaces

• serving as the site for ribosomal R N A synthesis

• producing A T P

A gene can best be defined as .

• a three-base triplet that specifies a particular amino acid

• noncoding segments of D N A up to 100,000 nucleotides long

• a segment of D N A that carries the instructions for one polypeptide chain

• an R N A messenger that codes for a particular polypeptide

Swelling until the cell lyses is likely to occur in blood cells immersed in .

• an isotonic solution

• a hypotonic solution

• a hypertonic solution

• blood plasma

Some hormones enter cells via .

• exocytosis

• primary active transport

• pinocytosis

• receptor-mediated endocytosis

If a t R N A had an A G C anticodon, it could attach to a(n)  m R N A codon.

• A U G

• U C G

• T C G

• U G A

Which of the following is NOT one of the concepts collectively known as the cell theory?

• Cells only arise from other cells.

• All cells must be motile and divide.

• The cell is the smallest unit of life.

• All organisms are made of one or more cells.

The myocardium (cardiac muscle tissue) relies on ions to synchronize its electrical activity and contractions for each heartbeat. You would expect to see relatively large numbers of which of the following embedded within their plasma membrane?

• transport proteins

• tight junctions

• connexons

• glycolipids

The movement of water across the plasma membrane can be described by all of the following EXCEPT .

• simple diffusion

• movement through aquaporins

• passive membrane transport

• carrier-mediated facilitated diffusion

If active transport establishes a concentration gradient with the use of A T P, then the concentration gradient can be looked at as

• potential energy that can be harnessed when molecules passively diffuse down the concentration gradient

• a byproduct of active

Which of the following would NOT be restricted (limited) by low levels of A T P?

• pinocytosis

• exocytosis

• osmosis

• phagocytosis

A cell engulfing a relatively large particle will likely utilize .

• phagocytosis

• pinocytosis

• receptor-mediated endocytosis

• exocytosis

If a cell is non-selectively engulfing samples of extracellular fluid, for example to absorb nutrients, it will likely utilize .

• phagocytosis

• pinocytosis

• receptor-mediated endocytosis

• exocytosis

If a cell is selectively reducing the concentration of a particular enzyme in the extracellular fluid it will likely utilize .

• phagocytosis

• pinocytosis

• receptor-mediated endocytosis

• exocytosis

Which of the following would NOT assist in establishing a resting membrane potential?

• Selective diffusion allowing more uncharged particles into the cell.

• Selective diffusion allowing fewer positively charged ions to diffuse into the cell.

• Active transport maintaining concentration gradients.

Myocardium (cardiac muscle tissue) must rhythmically contract for a lifetime. This requires a considerable amount of energy production by the cells. You would expect to see a relatively high amount of which organelle in these cells?

• lysosomes

• smooth endoplasmic reticulum

• mitochondria

• cytoskeleton

Beta cells in the pancreas produce and secrete the protein hormone insulin. You would expect to see a relatively large amount of which organelles in these cells?

• cytoskeleton, and peroxisomes

• smooth endoplasmic reticulum, and lysosomes

• Golgi apparatus, rough endoplasmic reticulum

Colchicine is a drug that can prevent the formation of microtubules. Which is the most likely effect colchicine would have on cell division?

• It will arrest mitosis by preventing the formation of spindle microtubules.

• It would have little or no effect on mitosis.