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BIO 235 > Chapter 3 > Flashcards

Chapter 3 Flashcards

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Biology 101 flashcards
1
Q

Cell

A

Living structural and functional units enclosed by a membrane

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2
Q

Cell Division

A

One cell divides into 2 identical cells

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3
Q

Cell Biology/cytology

A

Is the study of cellular structure and function

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4
Q

Plasma Membrane

A

Forms the cell’s flexible outer surface separating the cells internal/external environment

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5
Q

Internal environment

A

Everything inside the cell

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6
Q

External environment

A

Everything outside the cell

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7
Q

Cytoplasm

A

Consists of all the cellular contents between the plasma membrane and the nucleus.

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8
Q

What compartments does Cytoplasm consist of

A

Cytosol and Organelles

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9
Q

Cytosol

A

fluid portion of cytoplasm

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10
Q

Organelles

A

Includes cytoskeleton, ribosomes, endoplasmic reticulum, Golgi complex, lysosomes, peroxisomes and mitochondria. Each have specific functions, shape, characteristics

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11
Q

Nucleus

A

a large organelle that houses most of a cell’s DNA

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12
Q

Chromosomes

A

A single molecule of DNA associated with several proteins

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13
Q

Genes

A

Hereditary units that control most aspects of cellular structure and function

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14
Q

Plasma Membrane

A

Flexible yet sturdy barrier that surrounds and contains cytoplasm

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15
Q

What Structural Model does the Plasma Membrane use and describe it

A

Fluid mosaic model- the molecular arrangement of plasma membrane resembles a continually moving sea of fluid lipids that contains a mosaic of many different proteins.

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16
Q

Basic Structural framework of the Plasma Membrane

A

Lipid Bilayer

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17
Q

Lipid Bilayer

A

2 back to back layers made up of 3 types of lipid molecules

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18
Q

3 types of lipid molecules in the lipid bilayer

A

Phospholipids (75%, contain phosphorus), Cholesterol (20%, a steroid with an attached OH), Glycolipid (5%, lipid with an attached carbohydrate)

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19
Q

Amphipathic

A

molecules that have both polar and non-polar parts

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20
Q

Membrane Proteins

A

Integral or peripheral according to whether they are firmly embedded in the membrane

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21
Q

Integral Protein

A

Extend into or through the lipid bilayer and are firmly embedded into it

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22
Q

Transmembrane protein

A

Usually an integral protein. This means that they span the entire lipid bilayer and protrude into both the cytosol and extracellular fluid

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23
Q

Peripheral Protein

A

Not as firmly embedded in the membrane. They are attached to the polar heads of membrane lipids or to integral proteins at the inner/outer surface of the membrane

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24
Q

Glycoprotein

A

proteins with carbohydrate groups attached to the ends that protrude into the extracellular fluid

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25
Q

Glycocalyx

A

the carbohydrate portions of glycolipids and glycoproteins form an extensive sugary coating

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26
Q

4 Functions of Plasma Proteins

A

1.Act as barrier separating inside and outside of wall
2.Controls the flow of substances in and out of the cell.
3.Helps identify the cell to other cells
4.Participates in intracellular signalling

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27
Q

Membrane Protein Functions

A

Ion Channels, Carriers, Receptors, Enzymes, Linkers, Cell-identity markers

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28
Q

Ion Channels

A

Pores/holes that specific ions, such as K+ can flow through to get into/out of the cell

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29
Q

Carriers

A

Selectively moving a polar substance or ion from 1 side of the membrane to the other; also known as transporters

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30
Q

Receptors

A

Serve as cellular recognition sites; each type of receptor recognizes and binds a specific type of molecule

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31
Q

Ligand

A

a specific molecule that binds to a receptor

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32
Q

Enzymes

A

That catalyze specific chemical reactions at the inside/outside surface of the cell

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33
Q

Linkers

A

the anchor proteins into the plasma membranes of neighbouring cells to 1 another or to a protein filaments inside/outside the cell; peripheral proteins serve as enzymes/linkers

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34
Q

Cell-Identity Markers

A

May enable a cell to recognize other cells or same kind during tissue formation/recognize and respond to potentially dangerous foreign cells

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35
Q

Membrane Permeability-Permeable

A

Permeable means a structure permits passage of substances through it

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36
Q

Membrane Permeability-Impermeable

A

means a structure does not permit the passage of substances through it

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37
Q

Selective Permeability

A

Plasma membranes permit some substances to pass more readily than others through it

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38
Q

Concentration Gradient

A

Is the difference in the concentration of a chemical from one place to another (such as fro inside a cell to outside of a plasma membrane)

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39
Q

Electrical Gradient

A

Typically the inner surface of the plasma membrane is more negatively charged and then outer surface is more positively charged; a difference in the electrical charges between 2 regions

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40
Q

Membrane potential

A

the charge difference, because the electrical gradient occurs across the plasma membrane

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41
Q

Electrochemical Gradient

A

the combined influence of the concentration gradient and the electrical gradient on movement of a particular ion

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42
Q

What is essential to the life of a cell

A

transport across the plasma membrane

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43
Q

Passive Processes

A

when a substance moves down its concentration or electrical gradient to cross membrane using only its own kinetic energy/kinetic energy intrinsic to the particles moving/no input energy from the cell (diffusion)

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44
Q

Active Processes

A

Cellular energy used to drive the substance ‘uphill’ against its concentration or electrical gradient-usually in the form of ATP

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45
Q

Vesicles

A

another way substances may enter/leave cells- an active process in which tiny spherical membrane sacs are used- Active transport

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46
Q

Diffusion

A

is a passive process in which the random mixing of particles in a solution occurs because of the particles’ kinetic energy

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47
Q

Solutes and Solvents

A

Both undergo diffusion

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48
Q

Factors that influence diffusion rate

A

Steepness of concentration gradient, temperature, mass of diffusing substance, surface area, diffusion distance,

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49
Q

Simple Diffusion

A

a passive process in which substances move freely through the lipid bilayer of the plasma membranes of cells w/o the help of membrane transport proteins

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50
Q

Facilitated diffusion

A

solutes are too polar or highly charged to move through the lipid bilayer by simple diffusion can cross the plasma membrane by passive process

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51
Q

Channel-mediated facilitated diffusion

A

a solute moves down its concentration gradient across the lipid bilayer through a membrane channel

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52
Q

Ion Channels

A

Integral transmembrane proteins that allow passage of small inorganic ions that are too hydrophilic to penetrate the nonpolar layer of the lipid bilayer

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53
Q

Gated Channel

A

When part of the channel protein acts as a plug/gate, changing shape in one way to open pore and in another way to close it

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54
Q

Carrier/Transport-mediated facilitated diffusion

A

Moves a solute down its concentration gradient across the plasma membrane

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55
Q

Transport Maximum

A

the # of carriers available in a plasma membrane places an upper limit, on the rate in which facilitated diffusion can occur

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56
Q

Osmosis

A

A type of diffusion in which there is net movement of a solvent through a selectively permeable membrane

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57
Q

Aquaporins

A

Integral membrane protein that functions as water channels

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58
Q

Hydrostatic pressure

A

Forces water molecules to move back into the left arm

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59
Q

Osmotic Pressure

A

The solution with an impermeable solute also exerts a force, the pressure of a solution is proportional to the concentration of the solute particles that can’t cross the membrane–>higher solute concentration, higher solute’s osmotic pressure

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60
Q

Tonicity

A

Is a measure of the solutions ability to change the volume of cells by altering their water content

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61
Q

Isotonic Solution

A

Any solution in which a cell—for example, a red blood cell (RBC)—
maintains its normal shape and volume

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62
Q

Hypotonic Solution

A

A solution that has a lower concentration of solutes than the cytosol inside the RBCs

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63
Q

Hemolysis

A

To split apart RBC’s

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64
Q

Lysis

A

the rupture of other types of
cells due to placement in a hypotonic solution

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65
Q

Hypertonic Solution

A

has a higher concentration of solutes than does the cytosol inside
RBCs

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66
Q

Crenation

A

In a solution water molecules move out of the cells
faster than they enter, causing the cells to shrink. The shrinkage is called crenation

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67
Q

Active Transport

A

an active process because energy is required for carrier
proteins to move solutes across the membrane against a concentration
gradient. Two sources of cellular energy can be used to drive active
transport: (1) Energy obtained from hydrolysis of adenosine triphosphate
(ATP) is the source in primary active transport; (2) energy stored in an ionic
concentration gradient is the source in secondary active transport.

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68
Q

Primary Active Transport

A

energy
derived from hydrolysis of ATP changes the shape of a carrier protein,
which “pumps” a substance across a plasma membrane against its concentration gradient.

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69
Q

Pumps

A

carrier proteins that mediate primary active
transport

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70
Q

Na+/K+ Pump or Na+/K+ ATPase

A

The most prevalent primary active transport mechanism expels
sodium ions (Na+) from cells and brings potassium ions (K+) in. Because of the specific ions it moves, this carrier is called the sodium–
potassium pump. Because a part of the sodium–potassium pump
acts as an ATPase, an enzyme that hydrolyzes ATP, another name for
this pump is Na+–K+ ATPase.

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71
Q

Secondary Active Transport

A

the
energy stored in a Na+ or H+ concentration gradient is used to drive
other substances across the membrane against their own concentration gradients. Because a Na+ or H+ gradient is established by primary active transport, secondary active tr

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72
Q

Symporters

A

Move 2 substances in the same direction

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73
Q

Antiporters

A

move 2 substance in opposite directions across the membrane

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74
Q

Transport in vesicles

A

transport a variety of substances from one structure to another w/n cells

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75
Q

Vesicles

A

A small spherical sac

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76
Q

Exocytosis

A

Materials move out of a cell by the fusion with plasma membrane of vesicles formed inside the cell

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77
Q

Endocytosis

A

Materials move into a cell in a vesicle forms from the plasma membrane

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78
Q

Receptor Mediated Endocytosis

A

is a highly selective type of endocytosis by which cells take up specific ligands

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79
Q

Steps in Receptor Mediated Endocytosis

A

Binding, Vesicle Formation, Uncoating, Fusion with endosome, Recycling of receptors to plasma membrane, Degradation of lysosomes

80
Q

Phagocytosis

A

Is a form of endocytosis in which the cell engulfs large solid particles

81
Q

Phagocyte

A

Only a few body cells; macrophages–>located in many body tissues Neutrophils–> type of white blood cellT

82
Q

Two main types of Phagocytes

A

Macrophages & Neutrophils

83
Q

Pseudopod

A

Projections of its plasma membrane and cytoplasm. Pseudopods surround the particle outside the cell, and the membranes fuse to form a vesicle called a
phagosome.

84
Q

Phagosome

A

membranes of the pseudopod fuse to form a vesicle called a
phagosome.

85
Q

Bulk-Phase Endocytosis (Pinocytosis)

A

a form of endocytosis in which tiny droplets of extracellular fluid are
taken up. The plasma membrane folds inward
and forms a vesicle containing a droplet of extracellular fluid.

86
Q

Exocytosis

A

releases materials from a cell. (1) secretory cells that liberate digestive enzymes,
hormones, mucus, or other secretions and (2) nerve cells that
release substances called neurotransmitters

87
Q

Transcytosis

A

vesicles undergo
endocytosis on one side of a cell, move across the cell, and then
undergo exocytosis on the opposite side

88
Q

Cytoplasm

A

consists of all the cellular contents between the plasma
membrane and the nucleus, and has two components: (1) the cytosol
and (2) organelles

89
Q

Cytosol

A

is the fluid portion of the cytoplasm
that surrounds organelles (55%). is the site of many chemical reactions required for a
cell’s existence

90
Q

Cytoskeleton

A

a network of protein filaments that extends
throughout the cytosol

91
Q

3 Parts of Cytoskeleton

A

microfilaments, intermediate filaments, and
microtubules

92
Q

Microfilament

A

the thinnest elements of the cytoskeleton. They help generate
movement and provide mechanical support.

93
Q

Microvilli

A

nonmotile, microscopic fingerlike
projections of the plasma membrane. Greatly increase the surface area of the cell

94
Q

Intermediate Filaments

A

thicker than microfilaments but
thinner than microtubules. They are found in parts of cells subject to
mechanical stress; they help stabilize the position of organelles
such as the nucleus and help attach cells to one another

95
Q

Microtubule

A

help determine cell shape. They
also func-tion in the movement of organelles such as secretory vesicles,
of chromosomes during cell division, and of specialized cell projections,
such as cilia and flagella.

96
Q

Organelles

A

specialized structures within the cell
that have characteristic shapes, and they perform specific functions in
cellular growth, maintenance, and reproduction.

97
Q

Centrosome

A

Located near the nucleus, contains 2 components (centriole and Pericentriolar)

98
Q

Centriole

A

cylindrical structures composed of 9 clusters of 3 microtubules arranged in a circular pattern

99
Q

Pericentriolar Material

A

contains hundreds of ring shaped complexes composed of the protein tubulin

100
Q

Tubulin

A

complexes are the organizing centres for growth of the mitotic spindle; which plays a critical role in cell division for microtubule formation in non-dividing cells

101
Q

Tubules

A

complexes composed of the protein

102
Q

Cilium

A

numerous short hair-like projections that extend from the surface of the cell

103
Q

Flagellum

A

Similar in structure to cilia but are typically much longer, usually move an entire cell

104
Q

Ribosome

A

Are the sites of protein synthesis; these tiny structures reflect their high content of one type of RNA, each one includes more than 50 proteins.

105
Q

Endoplasmic Reticulum (ER)

A

A network of membranes in the form of flattened sacs or tubules; extends from nuclear envelope to which its connected and projects throughout the cytoplasm

106
Q

Two Types or ER

A

Rough and Smooth

107
Q

Rough ER

A

continuous with the nuclear membrane and usually is folded into a series of flattened sacs. The outer surface of rough ER is studded with ribosomes, the sites of protein synthesis. Proteins
synthesized by ribosomes attached to rough ER enter spaces within the ER for processing and sorting.

108
Q

Smooth ER

A

extends from the rough ER to form a network of
membrane tubules. synthesize fatty acids and steroids

109
Q

Golgi Complex

A

The first step in the transport pathway of the proteins synthesized.

110
Q

Cisterns

A

small, flattened membranous sacs with bulging edges (in Golgi Complex)

111
Q

Medial Cisterns

A

Sacs between the entry and
exit faces in the golgi complex

112
Q

Functions of the Golgi Complex

A
  1. Modifies, sorts, packages, and transports proteins received from the rough ER.
  2. Forms secretory vesicles that discharge processed proteins via exocytosis into extracellular fluid; forms membrane vesicles that ferry new molecules to the plasma membrane; forms transport vesicles that carry molecules to other organelles, such as lysosomes.
113
Q

Proteins arriving at, passing through, and exiting the Golgi
complex do so through

A

maturation of the cisternae and
exchanges that occur via transfer vesicles

114
Q

Lysosomes

A

Form from the golgi complex. can contain as many as 60 kinds
of powerful digestive and hydrolytic enzymes that can break down a
wide variety of molecules once lysosomes fuse with vesicles formed
during endocytosis.

115
Q

Autophagy

A

The process by which entire worn-out
organelles are digested

116
Q

Autophagome

A

the organelle to be digested is enclosed by a membrane derived from the ER to create a vesicle.

117
Q

Peroxisome

A

contain several oxidases, enzymes that can
oxidize (remove hydrogen atoms from) various organic substances.

118
Q

Functions of Lysosomes

A
  1. Digest substances that enter a cell via endocytosis and transport final
    products of digestion into cytosol.
  2. Carry out autophagy, the digestion of worn-out organelles.
  3. Implement autolysis, the digestion of an entire cell.
  4. Accomplish extracellular digestion.
119
Q

Proteasomes

A

Continuous destruction of unneeded, damaged, or faulty proteins is the function of tiny barrelshaped structures consisting of four stacked rings of proteins around
a central core

120
Q

Mitochondria

A

referred to as the “powerhouses” of the cell.

121
Q

What does a Mitochondria consist of

A

external mitochondrial
membrane and an internal mitochondrial membrane

122
Q

Mitochondrial Cristae

A

The internal mitochondrial membrane that contains a series of folds

123
Q

Functions of Mitochondria

A
  1. Generate ATP through reactions of aerobic cellular respiration.
  2. Play an important early role in apoptosis.
124
Q

Mitochondrial Matrix

A

The central fluid-filled cavity of a mitochondrion, enclosed by the internal mitochondrial membrane.

125
Q

Apoptosis

A

the orderly, genetically programmed death of a cell.

126
Q

Nucleus

A

is a spherical or oval-shaped structure that usually is the
most prominent feature of a cell

127
Q

nuclear envelope

A

separates the nucleus from the cytoplasm. Both layers of the nuclear
envelope are lipid bilayers similar to the plasma membrane.

128
Q

Nuclear Pores

A

control the movement of substances between the
nucleus and the cytoplasm.

129
Q

Nucleoli

A

function in producing ribosomes.

130
Q

Genes

A

control cellular structure and direct cellular
activities.

131
Q

Chromatin

A

Each chromosome is a long molecule of DNA that is coiled
together with several proteins

132
Q

Genome

A

The
total genetic information carried in a cell or an organism.

133
Q

Nucleosome

A

Electron micrographs reveal that chromatin has
a beads-on-a-string structure. The bead is a nucleosome

134
Q

Histones

A

Each nucleosome bead consists double-stranded DNA wrapped twice around
a core of eight proteins. Help organize the coiling and folding of DNA.

135
Q

Linker DNA

A

string between the
beads

136
Q

Chromatin Fiber

A

In cells that are not dividing, another histone promotes
coiling of nucleosomes into a larger-diameter chromatin fiber,
which then folds into large loops.

137
Q

Chromatids

A

Just before cell division takes
place, however, the DNA replicates (duplicates) and the loops condense even more, forming a pair of chromatids

138
Q

Functions of Nucleus

A

Controls Cellular structure, Directs cellular activties, Produces ribosomes in nucleoli

139
Q

Two Main Steps of Protein Synthesis

A

Transcription and Translation

140
Q

Proteome

A

refers
to all of an organism’s proteins

141
Q

Gene expression

A

a gene’s DNA is used as a template for synthesis of a specific protein.

142
Q

Base triplet

A

A sequence of three such nucleotides in DNA.

143
Q

Codon

A

Each DNA base triplet is transcribed as a complementary sequence of three nucleotides

144
Q

Genetic Code

A

is the set of rules that relate
the base triplet sequence of DNA to the corresponding codons of RNA
and the amino acids they specify

145
Q

First step in Protein Synthesis: Transcription

A

occurs in the nucleus, the genetic information represented by the sequence of base triplets in DNA serves as atemplate for copying the information into a complementary sequence of codons.

146
Q

Which three types of RNA are made from the DNA template:

A

Messenger RNA (mRNA), Ribosomal RNA (rRNA), Transfer RNA (tRNA)

147
Q

Messenger RNA

A

directs the synthesis of a protein.

148
Q

Ribosomal RNA

A

joins with ribosomal proteins to make
ribosomes.

149
Q

Transfer RNA

A

binds to an amino acid and holds it in place
on a ribosome until it is incorporated into a protein during translation. One end of the tRNA carries a specific amino acid, and the opposite end consists of a triplet of nucleotides called an anticodon.
By pairing between complementary bases, the tRNA anticodon attaches to the mRNA codon.

150
Q

Anitcodon

A

a triplet of nucleotides

151
Q

RNA Polymerase

A

An enzyme that catalyzes transcription of DNA.

152
Q

Promoter

A

The segment of
DNA where transcription begins, a special nucleotide sequence

153
Q

Terminator

A

Transcription of the DNA strand ends at another special nucleotide sequence. specifies the end of the gene

154
Q

Introns

A

do not code for parts of proteins.

155
Q

Extrons

A

do code for segments of a protein.

156
Q

Translation

A

the nucleotide sequence in an mRNA
molecule specifies the amino acid sequence of a protein. Ribosomes
in the cytoplasm carry out translation.

157
Q

Steps of Translation

A

The nucleotide sequence in an mRNA molecule specifies the amino acid sequence of a protein–>Ribosomes in cytoplasm carry out translation–>Small subunit of a ribosome has a binding site for mRNA–>larger subunit of a ribosome has a binding site for mRNA–>larger subunit has 3 binding sites for tRNA molecules; a P site, a A site and an E site–> P site binds to tRNA carrying next amino acid to be added to growing polypeptide, E binds to tRNA just before its released from the ribosome

158
Q

Polyribosome

A

Several ribosomes attached to the same mRNA

159
Q

Cell Division

A

the process by
which cells reproduce themselves.

160
Q

2 types of cell division

A

somatic cell division and reproductive cell division

161
Q

Somatic Cell

A

any cell of the body
other than a germ cell.

162
Q

Germ Cell

A

is a gamete (sperm or oocyte) or any precursor cell destined to become a gamete

163
Q

Somatic Cell Division

A

a cell undergoes a nuclear division called mitosis and a cytoplasmic division called cytokinesis. to produce two genetically identical cells. replaces dead or
injured cells and adds new ones during tissue growth.

164
Q

Reproductive Cell Division

A

the mechanism that produces
gametes.

165
Q

Meiosis

A

The 2 step process of reproductive cell division in which the number of chromosomes in the
nucleus is reduced by half.

166
Q

Cell Cycle in Somatic Cell Division

A

is an orderly sequence of events in which a somatic cell
duplicates its contents and divides in two.

167
Q

homologous chromosomes

A

The two chromosomes that
make up each pair of inherited chromosome from each parent

168
Q

Sex Chromosomes

A

designated X and Y. In females the homologous pair
of sex chromosomes consists of two large X chromosomes; in males
the pair consists of an X and a much smaller Y chromosome.

169
Q

diploid
(2n) cells

A

somatic cells contain two sets of chromosomes

170
Q

When a cell reproduces, it must replicate (duplicate) all its chromosomes to pass its genes to the next generation of cells. The cell
cycle consists of two major periods:

A

Interphase (when cell is not dividing) and Mitotic phase (When cell is dividing)

171
Q

Interphase

A

the cell replicates its
DNA, It also produces
additional organelles and cytosolic components in anticipation
of cell division. Interphase is a state of high metabolic activity; it is during this time that the cell does most of its growing.

172
Q

During which time does a cell does most of its growing.

A

Interphase

173
Q

3 Stages of Interphase

A

G1, S and G2

174
Q

G1 phase

A

the cell is metabolically active; it replicates most
of its organelles and cytosolic components but not its DNA; centromes replications also beings; total cell cycle time is 24 hours; lasts 8-10 hours

175
Q

G0 Stage

A

Cells that remain in G1 for a very
long time, perhaps destined never to divide again

176
Q

S Phase

A

the interval between G1 and G2, lasts about 8 hours. DNA replication occurs. As a result of DNA replication, the two identical cells formed during cell division later in the cell
cycle will have the same genetic material.

177
Q

G2 Phase

A

interval
between the S phase and the mitotic phase. It lasts 4 to 6 hours. During
G2, cell growth continues, enzymes and other proteins are synthesized
in preparation for cell division, and replication of centrosomes is completed.

178
Q

Mitotic Phase

A

results in the formation of two identical cells, consists of a nuclear
division (mitosis) and a cytoplasmic division (cytokinesis) to form two
identical cells.

179
Q

Stages of Mitosis or Mitotic Phase

A

Prophase, Metaphase, Anaphase, Telophase

180
Q

Prophase

A

During early prophase, the chromatin fibers
condense and shorten into chromosomes that are visible under the
light microscope. The condensation process may prevent entangling of the long DNA strands as they move during mitosis.

181
Q

Centromere

A

holds the chromatid pair together

182
Q

Mitotic Spindle

A

a football-shaped assembly of microtubules that
attach to the kinetochore

183
Q

Metaphase

A

the microtubules of the mitotic spindle align the centromeres of the chromatid pairs at the exact
center of the mitotic spindle.

184
Q

Anaphase

A

the centromeres split,
separating the two members of each chromatid pair, which move toward opposite poles of the cell. Once separated, the chromatids are termed chromosomes. As the chromosomes are pulled by the microtubules of the mitotic spindle during anaphase, they appear V-shaped because the centromeres lead the way, dragging the trailing arms of the chromosomes toward the pole.

185
Q

Telophase

A

begins after chromosomal movement stops. The identical sets of chromosomes, now at opposite poles of the cell, uncoil and revert to the threadlike chromatin form. A nuclear envelope forms
around each chromatin mass, nucleoli reappear in the identical nuclei, and the mitotic spindle breaks up.

186
Q

Events of Somatic Cell Division

A

G1, S phase, G2 phase, mitosis, cytokinesis

187
Q

Cell’s Three Possible Destinies

A

(1) to remain alive and functioning
without dividing, (2) to grow and divide, or (3) to die.

188
Q

Aptosis

A

a normal type of cell death

189
Q

Necrosis

A

a pathological type of cell death that results
from tissue injury

190
Q

Meiosis

A

the reproductive cell division that occurs in the gonads (ovaries
and testes), produces gametes in which the number of chromosomes
is reduced by half

191
Q

haploid (n) cells

A

gametes that contain a single set of 23
chromosomes.

192
Q

2 Stages of Meiosis

A

meiosis I and meiosis II.

193
Q

Meiosis I and II

A

, meiosis I begins with a diploid starting cell and ends
with two cells, each with the haploid number of chromosomes.
During meiosis II, each of the two haploid cells formed during meiosis
I divides; the net result is four haploid gametes that are genetically
diff erent from the original diploid starting cell.

194
Q

The sizes of cells are measured what units

A

micrometers

195
Q
A

BIO 235 (10 decks)

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