Ch4

Question 1

Cell membrane

Answer 1

the semipermeable membrane surrounding the cytoplasm of a cell.

Question 2

Cell theory

Answer 2

a theory in biology that includes one or both of the statements that the cell is the fundamental structural and functional unit of living matter and that the organism is composed of autonomous cells with its properties being the sum of those of its cells.

Question 3

Cytoplasm

Answer 3

the material or protoplasm within a living cell, excluding the nucleus.

Question 4

Eukaryotes

Answer 4

an organism consisting of a cell or cells in which the genetic material is DNA in the form of chromosomes contained within a distinct nucleus. Eukaryotes include all living organisms other than the eubacteria and archaebacteria.

Question 5

Eukaryotic cells

Answer 5

An organism whose cells contain a nucleus surrounded by a membrane and whose DNA is bound together by proteins (histones) into chromosomes. The cells of eukaryotes also contain an endoplasmic reticulum and numerous specialized organelles not present in prokaryotes, especially mitochondria, Golgi bodies, and lysosomes.

Question 6

Nucleus

Answer 6

the central and most important part of an object, movement, or group, forming the basis for its activity and growth.

Question 7

Organ

Answer 7

a part of an organism that is typically self-contained and has a specific vital function, such as the heart or liver in humans.

Question 8

Organelle

Answer 8

any of a number of organized or specialized structures within a living cell

Question 9

Organ cell

Answer 9

cilium. a hairlike projection from the surface of a cell; provides locomotion in free-swimming unicellular organisms. lysosome. an organelle found in the cytoplasm of most cells (especially in leukocytes and liver and kidney cells) cell nucleus, karyon, nucleus.

Question 10

Prokaryote 3

Answer 10

a microscopic single-celled organism that has neither a distinct nucleus with a membrane nor other specialized organelles. Prokaryotes include the bacteria and cyanobacteria.

Question 11

Prokaryotic cell

Answer 11

A prokaryote is a unicellular organism that lacks a membrane-bound nucleus, mitochondria, or any other membrane-bound organelle. … Eukaryotes are organisms, including humans, whose cells have a well defined membrane-bound nucleus (containing chromosomal DNA) and organelles.

Question 12

Ribosome

Answer 12

a minute particle consisting of RNA and associated proteins, found in large numbers in the cytoplasm of living cells. They bind messenger RNA and transfer RNA to synthesize polypeptides and proteins.

Question 13

Tissue

Answer 13

any of the distinct types of material of which animals or plants are made, consisting of specialized cells and their products.

Question 14

ATP (adenosine triphosphate)

Answer 14

a compound consisting of an adenosine molecule bonded to three phosphate groups, present in all living tissue. The breakage of one phosphate linkage (to form adenosine diphosphate, ADP ) provides energy for physiological processes such as muscular contraction.

Question 15

Cell wall

Answer 15

a rigid layer of polysaccharides lying outside the plasma membrane of the cells of plants, fungi, and bacteria. In the algae and higher plants, it consists mainly of cellulose.

Question 16

Central vacuole

Answer 16

a cellular organelle found in plant cells. It is often the largest organelle in the cell. It is surrounded by a membrane and functions to hold materials and wastes. It also functions to maintain the proper pressure within the plant cells to provide structure and support for the growing plant.

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

Cytoskeleton

Answer 18

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

Question 19

Endoplasmic Reticulum

Answer 19

a network of membranous tubules within the cytoplasm of a eukaryotic cell, continuous with the nuclear membrane. It usually has ribosomes attached and is involved in protein and lipid synthesis.

Question 20

Golgi apparatus

Answer 20

a complex of vesicles and folded membranes within the cytoplasm of most eukaryotic cells, involved in secretion and intracellular transport.

Question 21

Lysosomes

Answer 21

an organelle in the cytoplasm of eukaryotic cells containing degradative enzymes enclosed in a membrane.

Question 22

Mitochondria

Answer 22

an organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur. It has a double membrane, the inner layer being folded inward to form layers (cristae)

Question 23

Vacuole

Answer 23

a space or vesicle within the cytoplasm of a cell, enclosed by a membrane and typically containing fluid.

Question 24

Vesicle

Answer 24

a fluid- or air-filled cavity or sac, in particular.