Chapter 3 - Cells

Question 1

cytoplasm

Answer 1

a thick solution that fills each cell and is enclosed by the cell membrane

Question 2

organelle

Answer 2

specialized structures within a cell

Question 3

nucleus (biology)

Answer 3

a large, membrane-bound structure in most cells that contains the genetic code

Question 4

three main parts of a cell

Answer 4

plasma membrane, cytoplasm, nucleus

Question 5

plasma membrane

Answer 5

a membrane that surrounds the entire cell, forming its outer boundary; it is made up of phospholipids and cholesterol

Question 6

hormone

Answer 6

a regulatory substance produced in an organism and transported in tissue fluids such as blood or sap to stimulate specific cells or tissues into action

Question 7

cytoskeleton

Answer 7

a microscopic network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence

Question 8

ribosome

Answer 8

a minute particle consisting of RNA and associated proteins found in large numbers in the cytoplasm of living cells; it helps with protein synthesis

Question 9

endoplasmic reticulum (ER)

Answer 9

a network of membranes inside a cell through which proteins and other molecules move, made of two types: rough ER and smooth ER

Question 10

rough ER

Answer 10

part of endoplasmic reticulum that receives, folds, and transports newly made proteins

Question 11

smooth ER

Answer 11

part of endoplasmic reticulum that creates the membrane for the cell

Question 12

Golgi apparatus

Answer 12

a complex of vesicles (pouches) and folded membranes within the cytoplasm of most eukaryotic cells, involved in secretion (e.g. mucus) and intracellular transport

Question 13

mitochondrion

Answer 13

an organelle in the cell that produces energy for the cell (e.g. ATP)

Question 14

lysosome

Answer 14

the part of the cell that digests nutrients and helps to destroy harmful microbes

Question 15

centrosome

Answer 15

an organelle in the cell that organizes microtubules; involved in the process of cell division

Question 16

microtubule

Answer 16

a microscopic tubular structure present in numbers in the cytoplasm of cells, sometimes aggregating to form more complex structures

Question 17

centriole

Answer 17

a minute cylindrical organelle near the nucleus in animal cells, occurring in pairs and involved in the development of spindle fibers in cell division

Question 18

microvilli

Answer 18

small, fingerlike projections of the plasma membrane of some cells; these projections increase the surface area of the cell and thus increase its ability to absorb substances.

Question 19

cilia

Answer 19

extremely fine, hairlike extensions on the exposed or free surfaces of cells; they allow the cell to sense its surroundings, can be used to move things, and in taste buds they help people taste food

Question 20

flagellum

Answer 20

a single projection extending from the cell surface; a major example is the tail in a human sperm cell, which propels it forward

Question 21

nuclear envelope

Answer 21

a highly regulated membrane barrier that separates the nucleus from the cytoplasm

Question 22

nuclear pore

Answer 22

holes in the nuclear envelope that permit large molecules to move into and out of the nucleus

Question 23

nucleoplasm

Answer 23

a special type of cell material in the nucleus that contains a number of structures, the two most important being the nucleolus and the chromatin granules

Question 24

nucleolus

Answer 24

a dense region of the nuclear material that is critical in protein formation because it is where the cell makes the subunits that form ribosomes

Question 25

chromatin granules

Answer 25

a complex of DNA and protein found in eukaryotic cells; the primary function is to package long DNA molecules into more compact, denser structures

Question 26

chromosome

Answer 26

a long DNA molecule with part or all of the genetic material of an organism

Question 27

active transport

Answer 27

the mass movement of substances into and out of cells that requires the use of energy (ATP)

Question 28

passive transport

Answer 28

the mass movement of substances into and out of cells that through a method that does not require energy (e.g. osmosis, diffusion, or filtration)

Question 29

filtration

Answer 29

in the context of cells it refers to the movement of water and small solute particles, but not larger particles, through a filtration membrane; movement occurs from an area of high pressure to an area of low pressure

Question 30

crenation

Answer 30

a process resulting from osmosis in which red blood cells, in a hypertonic solution, undergo shrinkage and acquire a notched (a small cut or nick in something) or scalloped (having an edge or border marked with semicircles) surface

Question 31

lyse

Answer 31

(verb) undergo or cause to undergo lysis

Question 32

lysis

Answer 32

the breaking down of the membrane of a cell

Question 33

dialysis

Answer 33

a process where some solutes move across a selectively permeable membrane by diffusion and other solutes do not; this also explains how dialysis machines work in people with kidney failure (by selectively removing waste)

Question 34

phagocytes

Answer 34

a type of cell within the body capable of engulfing and absorbing bacteria and other small cells and particles

Question 35

pinocytosis

Answer 35

an active transport mechanism used to incorporate fluids or dissolved substances into cells by trapping them in a pocket of plasma membrane that pinches off inside the cell

Question 36

gene

Answer 36

the basic physical and functional unit of heredity. Genes are made up of DNA.

Question 37

genome

Answer 37

the complete set of genes or genetic material present in a cell or organism

Question 38

genomics

Answer 38

the branch of molecular biology concerned with the structure, function, evolution, and mapping of genomes

Question 39

proteomics

Answer 39

the study of all the proteins produced by an organism

Question 40

mitosis

Answer 40

a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth

Question 41

interphase

Answer 41

the period of the cell cycle during which the nucleus is not undergoing active cell division

Question 42

genetic counselors

Answer 42

people who use principles of genetics to advise clients who wish to produce offspring but are worried about possible genetic disorders

Question 43

genetic engineers

Answer 43

people who develop ways to manipulate the genetic code to produce a variety of therapies and enhanced biological characteristics of agricultural products

Question 44

genomics scientists

Answer 44

people who analyze the genetic codes of organisms to help us better understand structure and function, which may lead to better treatments for genetic disorders

Question 45

stem cell

Answer 45

the body's raw materials — cells from which all other cells with specialized functions are generated

Question 46

spindle fibers

Answer 46

microscopic protein structures that help divide genetic material during cell division; they also help organize cellular components