1.2 Ultrastructure of Cells

Question 1

Prokaryote

Answer 1

A unicellular organism that lacks a nucleus and membrane bound organelles.

Question 2

Eukaryote

Answer 2

A cell that contains a nucleus and membrane bound organelles

Question 3

Nucleoid

Answer 3

Area in prokaryotic cells in which DNA is concentrated, though not bounded by a membrane

Question 4

Plasma membrane

Answer 4

Aselectively-permeable phospholipid bilayer forming the boundary of cells

Question 5

Cell wall

Answer 5

A protective layer external to the plasma membrane in plant cells, bacteria, fungi, and some protists. In plant cells, the wall is formed of cellulose fibers embedded in a polysaccharide-protein matrix.

Question 6

Flagella

Answer 6

A long, whip-like filament that helps in cell motility. Many bacteria are flagellated, and sperm are flagellated.

Question 7

Pili

Answer 7

Appendages that allow bacteria to attach to each other and to transfer DNA.

Question 8

Cytoplasm

Answer 8

A jellylike fluid inside the cell in which the organelles are suspended and metabolic reactions occur.

Question 9

70S ribosomes

Answer 9

Ribosomes of prokaryotes.

Question 10

80S ribosomes

Answer 10

Larger ribosomes, found in eukaryotes

Question 11

Nucleus

Answer 11

Directs all activities of the cell and contains heredity material made of proteins and DNA

Question 12

Mitochondria

Answer 12

POWER HOUSE OF DA CELL

in which the biochemical processes of respiration occur to make ATP.

Question 13

Lysosome

Answer 13

Cell organelle filled with enzymes needed to break down certain materials in animal cells and single-celled eukaryotes.

Question 14

Centriole

Answer 14

Cell organelle that aids in cell division in animal cells only.

Question 15

Golgi apparatus

Answer 15

A system of membranes that modifies and packages proteins for export by the cell in Eukaryotes.

Question 16

Rough endoplasmic reticulum

Answer 16

Cellular site for protein synthesis. Has ribosomes attached.

Question 17

Smooth endoplasmic reticulum

Answer 17

Does not have ribosomes on its surface. In many cells, this contains collections of enzymes that perform specialized tasks, such as the synthesis of lipids.

Question 18

Conjugation

Answer 18

A primitive form of sexual reproduction that is characteristic of bacteria and some algae that involves the transfer of genetic material through pili.

Question 19

Electron microscope

Answer 19

A microscope that focuses an electron beam through a specimen, resulting in resolving power a thousandfold greater than that of a light microscope. A transmission electron microscope (TEM) is used to study the internal structure of thin sections of cells. A scanning electron microscope (SEM) is used to study the fine details of cell surfaces.