Biology Flashcards
(322 cards)
1
Q
Cell Theory
A
1) All living things are composed of cells
2) Cell is the functional unit of life
3) Cells arise from only cells
4) Cells carry genetic info via DNA which is passed from parent to daughter cells.
2
Q
Are viruses considered living things?
A
No, because they are Acellular, use RNA to carry info, and cannot reproduce on their own
3
Q
Eukaryotic Cells
A
Cells with membrane-bound organelles, nucleus, can form multicellular organisms
4
Q
Nucleolus
A
The subsection of the nucleus that synthesizes rRNA
5
Q
Lysosomes
A
Cell containing hydrolytic enzymes to break down substances.
6
Q
Endoplasmic Reticulum
A
Organelle which is continuous with the nuclear envelope. Rough ER has ribosome for protein secretion smooth ER is involved in lipid synthesis.
7
Q
Golgi Apparatus
A
The organelle that modifies, packages, and directs cellular products to specific cellular locations
8
Q
Peroxisomes
A
Organelle containing hydrogen peroxide which can break down fatty acid chains via beta oxidation. Participate in phospholipid synthesis and pentose phosphate pathway.
9
Q
Microfilaments
A
composed of actin provides structural protection and can cause muscle contraction via interactions with myosin. They help form the cleavage furrow during cytokinesis
10
Q
Microtubules
A
Composed of tubulin, they create pathways for motor protons to move along, They contribute to the structure of cilia and flagella, where they are organized into 9+2 ring structure.
11
Q
Kinesin
A
Motor Protein antereograde
12
Q
Dynein
A
Motor Protein retrograde
13
Q
Centrioles
A
found in centrosomes they are involved in microtubule organization into mitotic spindles
14
Q
intermediate filaments
A
involved in cell/cell adhesion and maintenance of cytoskeletons. They anchor organelles and include keratin and desmin
15
Q
Parenchyma
A
function parts of the organ often formed by epithelial cells
16
Q
epithelial cells
A
lining cells, they protect from the outside environment, some can absorb or secrete substances, some participate in sensation. They can be classified by layers (simple, stratified, pseudostratified), or by shape (cuboidal, columnar, squamous)
17
Q
connective tissue
A
Form the stroma or support structures, secrete substances to form extracellular matrix, consist of bone, cartilage, tendons, adipose, and blood for examples
18
Q
Prokaryotes
A
cells with no membrane-bound organelles, genetic material stored in single loop of DNA called nucleoid region. Include bacteria and archaea
19
Q
Archaea
A
extremophiles, can use chemical sources of energy, have similarities to both eukarotes and prokaryotes
20
Q
Domains of life
A
Archaea, Bacteria, Eukarya
21
Q
Bacteria shape classifications
A
Cocci (sphere) Bacilli (rod) Spirilli (spiral shaped)
22
Q
Obligate aerobes
A
need oxygen for metabolism
23
Q
Obligate anaerobes
A
Cannot survive in an oxygen environment and can only carry out anaerobic metabolism
24
Q
Faculative anaerobes
A
Survive in environments regardless of oxygen presence, will toggle between metabolic processes based on the environment
25
Aerotolerant anaerobes
Can't use oxygen for metabolism but can survive in an oxygen-containing environment.
26
Gram positive bacteria
When stained turn purple, they have thick cell walls composed of peptidoglycan and lipoteichoic acid
27
Gram Negative Bacteria
When stained turn pink-red, they have thin walls made of peptidoglycan and an outer membrane with phospholipids and lipopolysaccharides.
28
Chemotaxis
movement in response to chemical stimuli
29
ETC in prokaryotes
occurs in the cell membrane
30
Prokaryotic ribosomes vs Eukaryotic ribosomes
30S/50S vs 40S/60S
31
Binary fission
how prokaryotes multiply, chromosome replication occurs while cell grows in size until the cell wall grows inward along midline to divide cell into two
32
episomes
plasmids that can integrate into the genome
33
transformation
hen genetic material is taken up by a cell from its surroundings
34
Conjugation
transfer of genetic material between bacteria via conjugation bridges. Plasmids can be transferred from F+ to F- cells or a portion of the genome can be transferred from an Hfr cell to a recipient
35
transduction
transfer of genetic material via bacteriophage
36
transposons
genetic elements that can insert into or remove themselves from the genome
37
bacterial growth pattern
lag phase, exponential log phase, stationary phase, death phase
38
Capsid
viral protein coat
39
positive sense RNA virus
can be translated by host cell
40
negative sense RNA virus
complimentary strand must be synthesized and translated by host cell
41
retroviruses
contain single strand RNA from which DNA is made via reverse transcriptase. This DNA is then integrated into the genome
42
Lytic cycle
bacteriophase produces virons until cell lyses
43
Lysogenic Cycle
virus integrates into host genome and reproduces along with the cell. Can stay indefinitely or enter lytic cycle.
44
Prions
infectious misfolded proteins which trigger further misfolding of other proteins
45
Viroids
Small circles of complementary RNA that acts as plant pathogens
46
Diploid
2n
47
Haploid
n
48
Cell Stages
(G1, S, G2, M, G0) All but M can be called interphase
49
G1
Presynthetic gap, cells create organelles, proteins, and increase their size, restriction point occurs to check DNA for quality. This must be passed to proceed to S
50
S
DNA is replicated
51
G2
Further cell growth and replication of organelles in preperation for mitosis. ANother quality checkpoint occurs to go into mitosis
52
M
Mitosis and cytokinesis occurs
53
G0
cell performs its functions without preparing for division
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p53
functions in the two check points from G1 to S and G2 to M
55
Mitosis Phases
Prophase, metaphase, anaphase, telophase, cytokinesis
56
Prophase
Chromosomes condense, nuclear membrane dissolves, nucleoli dissapears, centrioles migrate to cell ends, spindle apparatus begins to form, kinetichores of each chromsome are contacted by spindle fibers
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metaphase
chromosomes align on the metaphase plate
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anaphase
sister chromatids separate
59
telophase
nuclear membrane reforms, spindle apparatus disappears, cytosol and organelles then split into two daughter cells via cytokinesis
60
Meiosis I
homologous chromosomes are separated from each other
61
Prophase I
Same events as mitosis prophase but homologous chromosomes intertwine (synapsis) and form tetrads. Crossing over occurs and accounts for Mendels second law (independent assortment)
62
Metaphase I
Homologous chromosomes line up on opposite sides of the metaphase plate
63
Anaphase I
homologous chromsomes are pulled to opposite poles of the cell accounting for Mendel's first law (segregation)
64
Telophase I
Chromosomes decondense and cell enters interkenisis after cytokinesis
65
Meiosis II
Sister chromatids seperate in a process similar to mitosis
66
Seminiferous tubules
Where sperm is produced in the testes
67
Sertoli Cells
Nourish Sperm
68
Leydig Cells
secrete testosterone and androgens
69
epididymis
where sperm gains motility and is stored
70
seminal vesicles
nourish sperm with fructose and produce alkaline fluid
71
prostate
produces alkaline fluid
72
bulbourethral glands
produce clear fluid that cleans out any remnants of urine and lubricates urethra during arousal
73
Spermatogenesis
four haploid sperm are formed from a spermatogonium
74
Sperm stages
After S stage primary spermatocyte, after meiosis I secondary spermatocyte, after meiosis II spermatids, after maturity spermatozoa
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follicles
where ova (eggs) are formed
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Oogenesis
one haploid ovum and a variable number of polar bodies are formed from an oogonium
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Ova stages
at birth oogonia have undergone replication and are arrested in prophase I, ovulated eggs are secondary oocytes arrested in metaphase II, when fertilize it will complete meiosis II to become a true ovum
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Zona pellucida
glycoproteins that protect oocyte and help sperm binding
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Corona Radiata
the layer of cells that adhere oocyte during ovulation
80
Menstral Cycle Phases
Follicular phase, ovulation, lucteal phase, and menstruation
81
Follicular phase
GnRH secretion stimulates FSH and LH which promotes follicle development. Estrogen is released stimulating vascularization and glandularization of the decidua
82
Ovulation
Stimulated by a surge in LH which is triggered by estrogen levels reaching a threshold and switching from negative to positive feedback effects. Results in an egg being released
83
Luteal Phase
LH causes the ruptured follicle to become the corpus luteum which secretes progesterone that maintains the uterine lining. High estrogen and progesterone levels cause negative feedback on GnRH LH and FSH
84
Menstruation
occurs when there is no fertilization. As estrogen and progesterone levels decline the endometrial lining sloughs off and the block on GnRN is removed.
85
Menopause
Menstruation stops and FSH and LH levels rise
86
Where does fertilization occur
The ampulla of the fallopian tube
87
Acrosomal apparatus
Sperm establishes this to inject its pronucleus into the egg
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Cortical Reaction
Term for the increase metabolic rate after fertilization
89
Indeterminate cleavage
results in cells capable of becoming any organism
90
determinate cleavage
results in cells commited to differentiation
91
Stages of embryotic brydevelopment
Egg, morula, blastula, 2 layered gastrula, 3 layered gastrula
92
Chorion
Contain chorionic villi which penetrate the endometrium and create the interface between maternal and fetal blood
93
Before the placenta is established what nourishes the embryo
yolk sac
94
amnion
produces amniotic fluid
95
gastrulation
process during embryonic development that changes the embryo from a blastula with a single layer of cells to a gastrula containing multiple layers of cells. Gastrulation typically involves the blastula folding in upon itself or dividing, which creates two layers of cells
96
ectoderm becomes
becomes epidermis, hair nail, epithelial cells, anal canal, and the nervous system and lens of the eye
97
mesoderm becomes
musculoskeletal system, circulatory, excretory, gonads, connective tissue,
98
endoderm
epithelial linings of respiratory and digestive system and parts of the pancrease, thyroid, bladder, and distal urinary tract
99
Neurulation
development of therse nervous system it begins after the formation of the three germ layers
100
Neural Crest Cells
become the peripheral nervous system
101
teratogens
substances that interfere with embryonic and fetal development causing defects or even death
102
morphogens
promote cell develpment down a specific line
103
cell competency
the ability of a cell to be influenced by morphogens
104
Differentiation
changes to a cell due to selective transcription
105
totipotent cells
can differentiate into all cell types including placental structures
106
pluripotent cells
differentiate into the three germ layers and their derivatives
107
multipotent cells
can differentiate into specific subsets of cells
108
reciprocal induction
when two tissues induce further differentiation in each other
109
apoptosis
programmed cell death
110
senescence
essentially aging, related to shortening of telomeres
111
Fetal Hemoglobin
higher oxygen affinity that adult heoglobin
112
umbelical arteries
carry deoxygenated blood from fetus to placenta
113
umbelical veins
carry oxygenated blood from placenta to fetus
114
foramen ovale
connects right atrium to left atrium to bypass lungs
115
ductus arteriosus
connects pulmonary artery to aorta bypassing lungs
116
ductus venosus
connects umbelical vein to inferior vena cava bypassing the liver
117
Dendrites
recieve impulses
118
soma
cell body
119
axon hillock
where axon begins and action potentials are initiated
120
axon
long appendage down action potentials move
121
synaptic bouton or terminal
where neurotransmitters are relased into cleft
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Nodes of Ranvier
exposed areas of mylenated axons that permit saltatory conduction
123
oligodendrocytes
mylenate the central nervous system
124
schwann cells
mylenate the peripheral nervous system
125
nerves / tracks
bundles of axons
126
ganglia
clusters of cell bodies of neurons of the same type in the peripheral nervous system
127
Nuclei
clusters of cell bodies of neurons of the same type in the central nervous system
128
Resting membrane potential
-70mV, maintained by sodium-potassium ATPase pumps
129
Astrocytes
nourish neurons, form BBB,
130
Ependymal cells
line ventricles and produce Cerebrospinal Fluid
131
Microglia
phagocytic cells in the CNS
132
Sodium Potassium Pumps
pump three sodium out for two potassium in
133
action potential
occurs when cell is depolarized to threshold voltage. Sodium channels open until causing influx up to peak where they are inactivated then potassium channels open. Potassium flows out repolarizing cells and stays open until hyperpolarization ocurrs. Then sodium-potassium pumps bring back to resting membrane potential.
134
Absolute refractory period
another action potential cannot occur
135
Relative refractory period
cell is hyperpolarized, a stronger than usual stimuli can cause an action potential
136
How AP causes Neurotransmitter release
AP opens voltage gated Calcium channels whose influx causes fusion of vesicles filled with NT with the cleft leading to their release
137
Peptide Hormones
made of amino acids, polar and cannot pass through membranes, bind to extracellular receptors to trigger signaling cascade. Hormones are water soluble, and can freely travel in the blood stream.
138
Steroid Hormones
Polar and can pass through membranes, binds to intracellular receptors, or binds to DNA to alter transcription. Must be carried by specific proteins.
139
Amino Acid Derivative Hormones
Share features of both peptide and steroid hormones.
140
Direct Hormones
Have major effects on non endocrine tissues
141
Tropic Hormones
Have major effects on other endocrine tissues
142
Gonadotropin releasing hormone GnRH
Promotes the release of FSH and LH
143
Growth Hormone Releasing Hormone GHRH
Promotes the release of growth hormone
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TRH
Promotes the release of TSH
145
Follicle Stimulating Hormone FSH
Promotes development of ovarian follicles in females and spermatogenesis in males
146
Luteinizing Hormone LH
Promotes ovulation in females and testoerone production in males
147
Adrenocorticotropic hormones
Promotes synthesis and release of glucocorticoids from adrenal cortex
148
Thyroid Stimulating Hormone
Promotes synthesis and release of T3 and T4
149
Prolactin
Promotes milk production
150
Endorphins
decrease perception of pain
151
Growth Hormone GH
promotes growth of bone and muscle and shunts glucose to these tissues. Increases blood glucose.
152
Antidiuretic hormone ADH also called vasopressin
Secreted in response to low blood volume and increased blood osmolarity and increases reabsorption of water in the collecting ducts of nephrons to increase blood volume
153
Oxytocin
promotes uterine contraction, milk ejection, and is involved in maternal bonding. Unusual as it has a positive feedback loop.
154
Where are T3 and T4 produced
Follicular Cells of the thyroid
155
Calcitonin
Produced by parafollicular cells it decreases plasma calcium concentrations by promoting excretion and decreasing absorption in the gut and promoting storage in bones
156
Parathyroid hormone
produced by the parathyroid glands. Increases blood calcium by decreasing excretion, activating vitamin D to increase absorption, promotes resorption of phosphate from bone and reduces the reabsorption of phosphate in kidney. Vitamin D promotes absoprtion of phosphate from gut so they cancel each other out
157
glucocorticoids
cortisol and cortisone they increase blood glucose, reduce protein synthesis, inhibit immune system, and are stimulated by ACTH
158
Mineralocorticoids
Examples include aldosterone, they promote sodium reabsorption in the distal convoluted tubule and colecting duct to also increase water reabsorption. Aldosterone is regulated by the renin angiotensin pathway
159
Where are catecholamines released
adrenal medulla releases them including epinephrine and norepinephrine
160
Alpha cells
produce glucagon which raises blood glucose by stimulating protein and fat degradation, glycogenolysis, and gluconeogensis.
161
beta cells
produce insulin which lowers blood glucose levels, stimulates glucose uptake by cells, and promotes glycogen fat and protein synthesis.
162
lambda cells
produce somatostatin
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somatostatin
inhibits insulin and glucagon secretion
164
Intestinal and Gastric Hormones
secretin, gastrin, and cholecystokinin
165
Atrial natriuretic peptide
promotes excretion of salt and water in kidneys in response to stretching of the atria from high water volume in the blood
166
thymosin
secreted by the thymus for proper t cell development
167
Pathway of air in respiration
nares, pharynx, larynx, trachea, bronchi, bronchioles, alveoli
168
surfactant
reduce surface tension at the liquid-gas interphase of alveoli to prevent it from collapsing
169
visceral pleura
lies adjacent to the lung
170
parietal pleura
lines the chest wall
171
intrapleural space
between visceral and parietal pleura
172
diaphragm
thin skeletal muscle that created pressure differential for breathing
173
muscles involved in breathing
diaphragm and the intercostal muscles
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negative pressure breathing
pressure differential expands lungs by dropping the preassure within and draing lung from environment. This is achieved by diaphragm contracting.
175
Total Lung Capacity
Maximum volume of air remaining in the lungs
176
Residual volume
volume of air remaining after fully exhaling
177
vital capacity
difference between total lung capaciy and residual volume basically difference between the minimum and maximum amounts of air in the lungs
178
tidal volume
air volume moved in a normal breath
179
expiratory reserve volume
volume of additional air that can be forcibly exhaled after a normal exhalation
180
inspiratory reserve volumes
volume of additional air that can be forcibly inhale after a normal exhalation
181
ventilation is regulated by what brain structure
medulla oblongata
182
Pathway of blood from right atria
right atria, tricuspid valve, right ventricle, pulmonary valve, pulmonary artery, lungs, pulmonary veins, left atrium, mitral valve, left ventricle, aortic valve, aorta, arteries, arterioles, capillaries, venules, veins, venae cavae, right atrium
183
electric conduction in the heart
SA, AV, bundle of His, purkinje fibers
184
Systole
ventricular contraction where AV valve is closed
185
Diastole
heart is relaxed
186
cardiac output
heart rate X stroke volume
187
portal system
when blood passes through two capillary beds in series
188
hepatic portal system
blood travels from gut beds to liver beds
189
hypophyseal portal system
blood travels from hypothalamus beds to anterior pituitary beds.
190
renal portal system
glomerulus to vasa recta through efferent arterioles
191
Aspects that cause a right shift in the oxyhemoglobin dissociation curve. What does this mean?
High CO2, High H+, Low pH, high temperature, high 2,3BPG, cause a right shift this means that there is a decreased affinity for oxygen
192
Innate Immunity
Defenses that are always active but do not target specific invaders and do not maintain memory. Also called non specific immunity
193
Adaptive Immunity
Defenses that take time to activate but are specific and maintain memory they are also called specific immunity
194
Where are immune cells made
bone marrow
195
Where are immune responses mounted and B cells activated
Spleen and lymph nodes
196
Where is the site of T cell maturation
Thymus
197
Leukocytes
White blood cells
198
Defensin
antimicrobial compound secreted the skin
199
Complement system
punches holes in the cell walls of bacteria making them osmotically unstable
200
interferons
given off by virally infected cells they help prevent viral replication and dispersion to nearby cells
201
Macrophages
ingest pathogens and present them on major histocompatibility complex molecules (MHC)
202
MHC class I
Present in all nucleated cells and display endogenous antigens to cytotoxic T-cells (CD8+)
203
MHC Class II
Present in some antigen-presenting cells display exogenous antigens to helper T-cells (CD4+)
204
Dendritic cells
antigen presenting cells in the skin
205
Natural killer cells
they attack cells not presenting MHC molecules which would include virally infected cells and cancer cells
206
Granulocytes
include neutrophils, eosinophils, and basophils
207
Neutrophils
ingest bacteria, specifically opsonized bacteria (bacteria marked by antibodies) they follow the bacteria via chemotaxis
208
Eosinophils
they release histamine in response to allergic reactions and invasive parasitic infections
209
Basophils
used in allergic reactions Mast cells are similar cells found in the skin
210
Humoral Immunity
Centered on antibody production by plasma cells which are activated by B-cells
211
Memory B cells
lie in wait for second exposure to a pathogen and cal mount a more rapid and vigorous response (secondary response)
212
Cell mediated immunity is centered around white type of cell
T cells
213
Helper T Cells CD4+
Respond to antigens on MHCII by secreting lymphokines to activate immune difenses.
214
Interferon gamma
activates macrophages and secreted by helper T cells 1
215
Helper T cells II
activate B cells
216
Cytotoxic T Cells CD8+
responds to antigens on MHC-1 and kill virally infected cells
217
Supressor T Cells Treg
Tone down immune response after infection
218
Memory T Cell
serve similar function to memory B cell
219
Active immunity
Activation of B cells to produce antibodies
220
Passive Immnity
transfer of antibodies to an individual
221
Thoracic duct
connect lymphatic and circulatory system
222
purpose of the lymphatic system
equalizes fluid distribution, transports fats and chylomicrons, provides sites for mounting immune responses
223
Accessory organs of digestion
salivary glands, pancreas, liver, and gallbladder
224
enteric nervous system
wall of alimentary canal and controls peristalsis. Regulated by the sympathetic and parasympathetic nervous system
225
Hormones that support thirst
antidiuretic hormone, aldosterone
226
Hormones that support hunger
glucagon, ghrelin
227
Hormones that support satiety
leptin and cholecytokinin
228
stomach mucous cells
synthesize bicarbonate buffer
229
Chief cells
secrete pepsinogen, which when activated by stomach acid (HCl) becomes pepsin which works to break down proteins.
230
Parietal Cells
secrete HCl and intrinsic factor which is needed for vitamin B12 absorption
231
G-Cell
secretes gastrin which increases HCl secretion as gastric motility
232
Dissachardases
break down dissarchide into monosaccharaides hey are brush border enzymes
233
Enteropeptidase
activates trypsinogen and procarboxypeptidase initiating an activation cascade
234
Secretin
stimulates the release of pancreatic juices into the digestive track and slows motility
235
Cholecystokinin
stimulates bile release, and pancreatic juices, and deals with satiety
236
Acinar Cells
Located in the pancreas and produce bicarbonate, pancreatic amylase, pancreatic peptidases (trypsinogen, chymotrypsinogen, carboxypeptidase A and B), and pancreatic lipase
237
Jejunum and Ileum function
major in absorption via villi and microvilli which contain lacteals and capillary beds
238
Nephron segments in order
PCT, descending limb of the loop of Henle, ascending lib of the loop of Henle, DCT, collecting duct
239
PCT
site of bulk reabsorption of glucose, amino acids, soluble vitamins, salt, and water. Site of secretion of H+, K+, ammonia, and urea
240
descending limb of the loop of Henle
Permeable to water, not salt so water is reabsorbed as it moves down into the more concentrated renal medulla.
241
Countercurrent multiplier system
Vasa recta and nephron flow in opposite directions allowing maximal reabsorption of water
242
Ascending limb of the loop of Henle
Permeable to salt but not water so salt is reabsorbed.
243
DCT
responsive to aldosterone and is the site of salt reabsoption and waste product excreption
244
Collecting duct
responsive to aldosterone and antidiuretoc hormone and has variable permeability depending on the bodies need.
245
aldosterone
steroid hormone regulated by renin, angiotensin, aldosterone, system that increases sodium reabsorption and thus water reabsorption
246
Antidiuretic hormone
peptide hormone synthesized by hypothalamus and released by the posterior pituitary in response to low blood volume or high blood osmolarity. It increases permeability of collecting duct to increase water reabsorption
247
epidermis Layers
Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum.
248
Melanocytes
make melanin
249
Langerhans Cell
macrophages in skin. serve antigen presenting cells
250
dermins layers
papillary layer, reticular layer
251
merkels cells
deep pressure and texture
252
free nerve endings
pain
253
meissners corpuscles
light touch
254
ruffini endings
stretch
255
pacinian corpuscles
deep pressure and vibration
256
Skeletal muscle
voluntary, striated, polynucleated
257
red twitch fibers
carry out oxidative phosphorylation
258
white twitch fibers
use anaerobic metabolism
259
Smooth Muscle
In respiratory, reproductive, cardiovascular, and digestive systems. Nonstriated, involuntary, and uinucleated.
260
myogenic activity
can contract without neural imput found in smooth and cardiac muscle
261
cardiac muscle
striated, involuntary, uninucleated/binucleated, myogenic. Connected with intercalated discs that contain gap junctions
262
sarcomere
funcitonal unit of muscle consisting of myosin and actin. Troponin and tropomyosin are found on actin and regulate interactions between the filaments.
263
Z line
end boundaries of sarcomere
264
M line
middle of sarcomere
265
I band
contains only thin filament actin
266
H zone
contains on thick filament myosin
267
A band
The thick filament in its entirety it is the only part of the sarcomere that maintains a constant length
268
T tubules
connect to sarcolemma and allow action potential to reach all parts of the muscle
269
what causes the sarcolemma to depolarize
acetylcholine from nerves
270
How does calcium cause power strokes
calcium binds to troponin which shifts tropomyosin, and exposes myosin binding sites on the actin
271
tetanus
prolonged and stronger contraction from frequency summation of twitches
272
creatine phosphate
makes ATP in muscles
273
myoglobin
oxygen reserve in muscles
274
compact bone
provides strength. Dense
275
spongy bone
filled with bone marrow
276
Long bones
shaft is called diaphyses which flare to form metaphyses and terminate in epiphyses. Epiphysis contains epiphyseal growth plate
277
periosteum
connective tissue surrounding bones
278
tendons
attach bones to muscles
279
ligaments
attach bones to bones
280
how are bones organized internally
into rings called lamellae around central canal. Unit is called osteon
281
lacunae
between lamellar rings where osteocytes reside. Connected to canaliculi to allow nutrient and waste transfer
282
osteoblasts
build bone
283
osteoclasts
break down bone
284
Parathyroid hormone bone consequence
increases resorption of bone increasing blood calcium and phosphate
285
vitamin D
increases resorption of bone increasing blood calcium and phosphate
286
Calcitonin
increases bone formation
287
chondrocytes
secrete chondrin to make cartilage
288
endochondral ossification
how bones are formed from cartilage in fetal life
289
immovable joints
fused together to make sutures
290
movable joints
contain synovial capsule
291
articular cartilage
coating of bones in joints to aid movement
292
antagonistic pairs
muscles that serve in opposite functions so that when one contracts the other relaxes.
293
hemizygous
having only one allele like the male sex chromosome
294
complete dominance
effects of one allele completely mask the effects of others
295
codominance
more than one dominant allele
296
incomplete dominance
no dominant alleles have an intermediate phenotype when heterozygous
297
penetrance
the proportion of the population with a given genotype who express the phenotype
298
expressivity
the varying phenotypic manifestation of a given genotype
299
Mendels first law
law of segregation. Organisms have two alleles for each gene which segregate during meiosis resulting in gametes carrying one gene.
300
Mendels second law
independent assortment. States that inheritance of one allele does not influence the probability of inheriting an allele for a different trait.
301
point mutation
substitution of singular nucleotide for another
302
frameshift mutation
moving the three letter transcriptional reading frame
303
silent mutation
has no effect
304
missense mutation
results in substitution of one amino acid for another
305
nonsense mutation
early stop codon
306
deletion mutations
large segment of DNA is lost
307
duplication mutation
segment of DNA is copied multiple times
308
inversion mutation
segment of DNA is reversed
309
insertion mutation
segment of DNA is moved from one chromosome to another
310
translocation mutation
segment of DNA is swapped with a segment of DNA from another chromosone
311
Genetic leakage
flow of genes between species through hybrid offspring
312
genetic drift
when composition of gene pool changes as a result of chance
313
founder effect
results from bottle necks that suddenly isolate small population leading to inbreeding and increased prevalence of certain homozygous genotypes
314
recombinant frequency
likelihood of two alleles being separated during crossing over
315
punctuated equilibrium
evolution slow process with intermittent bursts of change
316
Stabilizing selection
excludes extremes
317
directional selection
moves to one extreme
318
disruptive selection
moves to two extremes. Can lead to speciation
319
adaptive radiation
rapid emergence of multiple species from common ancestor each of which occupies its own niche
320
divergent evolution
two species sharing common ancestor become more different
321
parallel evolution
two species sharing common ancestor evolve in similar ways
322
convergent evolution
two species not sharing common ancestor evolve in similar ways
