Cell Structure and Cell Division

Question 1

cell

Answer 1

was first used by Robert Hooke in 1665, when he examined the bark of cork tree under a compound microscope

Question 2

3 major parts of a cell

Answer 2

• plasma/cell membrane
• the cytoplasm
• the nucleus

Question 3

plasma membrane

Answer 3

• 45% lipid, 50% protein, 5% carbohydrate
• lipids are arranged in bilayer with peripheral proteins attached and integral proteins extending through the membrane
• envelops entire cell
• provides a barrier for cell by regulating movement of materials in & out of cell

Question 4

cytoplasm

Answer 4

• mixture of water, salts, and organic molecules to form a thick fluid and organized structures called organelles
• region between plasma membrane and nucleus
• region of cellular metabolism and other activities that maintain the cell

Question 5

cytosol

Answer 5

• thick, gel-like fluid composed mostly of water and proteins
• surrounds organelles
• transport substances between organelles and other cell structures

Question 6

organelles

Answer 6

• formed bodies
• suspended within cytosol
• varied activities that maintain the cell

Question 7

centrioles

Answer 7

• composed of nine groups of three microtubles, forming a cylinder
• near the nucleus in the centrosome
• participate in cell division

Question 8

Cilia

Answer 8

• long, slender projections of the plasma membrane of certain cells
• extend outward, away from the cell surface
• rhythmic movements propel fluids

Question 9

microvilli

Answer 9

• numerous, tiny folds of the plasma membrane that increase the surface area of certain cells
• extend outward away from the plasma membrane
• increase the plasma membrane surface area for absorption or secretion

Question 10

ribosomes

Answer 10

• very, small, spherical structures composed of 60% RNA and 40% protein
• either attached to the ER or unattached in the cytoplasm
• provide attachment site for mRNA during protein synthesis

Question 11

rough endoplasmic reticulum (RER)

Answer 11

• branching tubules that may be flattened or tubular, with attached ribosomes
• extends between nucleus and plasma membrane
• site of protein synthesis

Question 12

smooth endoplasmic reticulum (SER)

Answer 12

• branching tubules that may be flattened or tubular, without ribosomes
• winds and twists throughout cytoplasm
• site of lipid and carbohydrate assembly

Question 13

golgi apparatus (complex)

Answer 13

• series of flattened, disc-shaped sacs
• usually near nucleus with secretory vesicles near plasma membrane
• prepares and packages cellular products of transport

Question 14

mitochondria

Answer 14

• spherical or sausage shaped with inner folded membrane
• randomly throughout cytoplasm
• site where nutrients are broken down and ATP is produced during cellular respiration

Question 15

peroxisomes

Answer 15

• small, spherical
• randomly throughout cytoplasm
• site where free radicals are detoxified

Question 16

lysosomes

Answer 16

• small, spherical
• randomly throughout cytoplasm
• contains enzymes that breakdown materials brought into the cell, or releases enzymes out of the cell to digest

Question 17

nucleus

Answer 17

• large structure composed of a double membrane that contains nucleic acids
• often located in center of cell
• contains DNA, which regulates protein synthesis and cell division and contains RNA

Question 18

nuclear envelope

Answer 18

• double membrane with large nuclear pores
• surrounds nucleoplasm
• regulates movement of materials between cytoplasm and nuceloplasm

Question 19

nucleoplasm

Answer 19

• gel-like fluid consisting of water, nucleic acids, and proteins
• contained within the nuclear envelope
• site of nucleic acids (DNA & RNA)

Question 20

Nucleoli

Answer 20

• small spheres containing RNA + proteins
• grouped in area of nucleoplasm
• site of RNA synthesis

Question 21

Chromatin

Answer 21

• threadlike material composed of DNA and proteins
• throughout the nucleoplasm
• DNA contains genes which control protein synthesis

Question 22

skeletal muscle cell shape

Answer 22

long and cylindrical. the shape allows it to extend long distances to connect to bones & contract

Question 23

neuron cell shape

Answer 23

star-shaped or long and narrow with many branches

Question 24

cheek cell shape

Answer 24

round and flat

Question 25

cell cycle

Answer 25

a series of events which a eukaryotic cell must undergo in order to divide to produce the two daughter cells

Question 26

interphase

Answer 26

the cells grow and get ready to divide. 2 gap phases: G1 and G2 and S (synthesis) phase where DNA replicates and get ready for cell division.

Question 27

Mitotic (M) phase

Answer 27

• prophase
• prometaphase
• metaphase
• anaphase
• telophase
• cytokinesis & karyokinesis

Question 28

cytokinesis

Answer 28

actual separation of the two daughter cells

Question 29

karyokinesis

Answer 29

the nucleus divides into two daughter nuclei

Question 30

G0 phase

Answer 30

Cells that don’t divide because of genetic programming (ex: neurons)

Question 31

G1 Phase

Answer 31

growth and normal metabolic roles

Question 32

Synthesis Phase

Answer 32

DNA and organelle replication

Question 33

G2 Phase

Answer 33

growth and preparation of mitosis

Question 34

somatic cell division

Answer 34

• when cells reach a certain size/age they divide to form identical daughter cells
• provides body growth, replacement of older cells, and repair injured parts of body
• 2 processes: mitosis & cytokinesis

Question 35

Mitosis aka nuclear division

Answer 35

• the sequence of changes that the nucleus and its DNA undergo in preparation for cell division.
• Includes four phases: prophase, metaphase, anaphase, and telophase

Question 36

Cytokinesis aka cytoplasmic division

Answer 36

the sequence of changes occurring in the cytoplasm and plasma membrane resulting in physical separation to form two daughter cells.

Question 37

Cytokinesis aka cytoplasmic division

Answer 37

the sequence of changes occurring in the cytoplasm and plasma membrane resulting in physical separation to form two daughter cells.