1
Q
Pros of life in water
A
- high heat capacity = stable temp
- metabolic waste easily removed in h2o
- sound transmits well
- H2O supports body
- aquatic reproduction by broadcasting gametes into water to avoid drying out
2
Q
cons of life in water
A
- density and viscosity costs locomotion and visual range
- limits metabolic rates (bc takes more energy to pull O2 from water)
3
Q
comparing life in air vs life in water
A
AIR:
- low heat capacity = temp extremes
- low viscosity = air flows easily
- O2 diffuses faster in air
- less dense due to gravity
WATER:
- high heat capacity = stable temps
- universal solvent (H2O dissolves/transports molecules)
- high viscosity due to strong intermolecular bonds
- O2 needs to be dissolved (less O2)
- high density (pressure changes with depth)
4
Q
what are some challenges on land?
A
- desiccation
- getting rid of toxic wastes while minimizing H2O loss
- breathing air
- sensory systems and structures
- protective coating or internal structure for gamete exchange
- structures supporting gravity
5
Q
adaptations to avoid desiccation: mechanisms to reduce water loss
A
- skin and waxy cuticle
- behaviour (hunting at night)
- production of concentrated urine (loop of Henle)
6
Q
what is loop of Henle?
A
- vertebrate kidney (U shaped)
- reabsorbs water and NaCl to produce highly concentrated urine
7
Q
adaptations to avoid desiccation: mechanisms to replace water loss
A
- drink and eat moist foods
- metabolic water (water generated through process of metabolism)
8
Q
adaptations to avoid desiccation: develop desiccation tolerance
A
- going into aestivation (dormancy)
- example = lungfish. during dry seasons they dig into mud and curl up. a protective cocoon mucus forms. stays in that state until H2O returns
9
Q
adaptations to avoid desiccation: Parthenogenesis
A
- form of aesexual reproduction (low cost)
- occurs in unstressed, moist environments)
10
Q
performance curve (describe what happens below 0 degrees and approaching 45 degrees)
A
- cell functions between 0 and 45 degrees
Below 0 degrees
- ice crystals;s destroy organelles and cell membranes
Approaching 45 degrees
- proteins and nucleic acids unfold and lose function
11
Q
temperature extremes adaptations
A
- endothermy (produce own heat)
- sweat to cool down
- behaviour (hunting at night)
- freeze avoidance to lower freeze point
12
Q
temperature extremes adaptations: freeze tolerance
A
- ice nucleating proteins ( organisms can control where ice crystals form to prevent ice from spreading through entire body)
- higher proportion of phospholipids
- lower metabolism
13
Q
excretions of waste
A
- ammonia is toxic (usually aquatic animals)
- urea = less toxic and can be stored at higher temp (prevents water loss)
- uric acid = insoluble (white paste in bird poo)
14
Q
how do they protect reproductive structures from desiccation?
A
- gametes are fertilized internally (which means they need to find mates)
- embryos protected by
- some animals have eggshells
- amniote vertebrates have membrane that encases and protects amniotic fluid that surrounds embryo
15
Q
gas exchange to transport O2 and CO2: aquatic animals
A
- less O2 bc of high density and viscosity (takes more energy to move O2 across water surface)
- easier to get rid of CO2
16
Q
gas exchange to transport O2 and CO2: gas exchange in air
A
- diffusion is 10 000 times faster than in water
- higher O2 content bc of low density + viscosity
- not easy to remove CO2
- must be covered by thin film of fluid
- has evaporative loss
17
Q
gas exchange to transport O2 and CO2: internalized gas exchange
A
- inward, protected, moist structures
- higher SA
- reduces H2O loss
- example = tracheal sys. in insects
18
Q
sensing in air: light
A
- radiant energy
- bigger eyes in air = better visual range
- bigger eyes in water = visual range not better
19
Q
sensing in air: sound
A
- waves of pressure
- less compressible = faster
- more compressible = slower
- vertebrate ear translates air into fluid energy
20
Q
sensing in air: smell and taste
A
- small molecules
- olfactory system in mosquitoes has hair like chemosensory structures on antennae. also uses pores to allow molecules to enter
21
Q
Does SA;A increase or decrease as animals get larger?
A
- decreases
- support = area dependent
- mass = volume dependent
22
Q
what is isometric scaling?
A
proportional scaling
23
Q
what is allometric scaling?
A
- alloios = different
- disproportionate scaling
24
Q
what is Kleiber’s Law?
A
- metabolic rate = (mass)^3/4
- smaller animals uses energy less efficiently
- bigger animals uses energy more efficiently
25
in allometric scaling, what does it mean when slope is greater than 1
- gets bigger
- example: skeleton has a slope higher than 1 so that means the skeleton got bigger as body size got bigger
26
in allometric scaling what does it mean when slope is less than 1
- gets smaller
- example: metabolic rate has a slope smaller than 1 so that means MR gets slower as body gets bigger
27
how does skeleton support the body?
- having skeletons = stronger limbs
- rib cage = thick and heavy to support lungs and organs
- articulated spine (spine being able to move) to support limbs, attachment points to strong pelvic + pectoral girdles
- mobile neck
28
how does stance support body?
- limbs positioned to support body system
- small animals = sprawling stance (ants)
- bigger animals = upright so that bones can support mass of body
29
compare locomotion on land vs water
LAND
- speed is limited by body mass
- larger body mass = slower
WATER
- having bigger body mass doesn't matter bc water supports weight
(which is why whales can get so big)
30
what are some challenges on land?
- desiccation
- creating air (gas exchange)
- sensory systems (detecting light, sound, smell)
- gravity
- gemete protection
31
what is homeostasis?
- homeo= the same; stasis= standing or stopping
- to maintain steady internal enviro
- uses biochemical rxn to control it
32
what does "internalized" external cells have?
- rapid turnover rate
- lethal enviro to microbes
- secretions to protect gut lining
33
extracellular cells are connected through what?
homeostasis
34
what is osmoregulation?
- regulation of internal osmotic (salt/water/waste) environment
- regulated by bulk flow, diffusion, osmosis
35
what is bulk flow?
movement of liquid from area of high to low pressure (hydrostatic pressure )
36
what is diffusion?
solutes moving from area of high to low concentration
37
what is osmosis?
solute moving from low to high [solute] by crossing semipermeable membrane
38
what is hyperosmotic?
- lots of solutes
- high pressure = low potential
39
what is hypoosmotic?
- low solutes
- low pressure = high potential
40
what does water potential include?
osmotic potential, hydrostatic gravity, humidity
41
explain the steps of excretory organ (as mechanism for osmoregulation)
1. Filtration (non-selective) filters out water, salt, ions, waste
2. Secretion (selective) the wastes and solutes are secreted in tubule
3. reabsorption (selective) reabsorbs salts, water, etc back to the capillary
42
what is excretion as a mechanism for osmoregulation?
the elimination of waste (that aids in controlling content of extracellular fluid (salt, water, pH)
43
factors of internal environment that are regulated by homeostasis
- temp
- concentration of water and NaCl
- volume + pressure of blood vessels
- concentration of waste chemicals
- concentration of O2 and CO2
- pH
- nutrient concentration for energy production by cells
44
what happens in a hypoosmotic enviro?
- cells swell
- low solutes and high water
45
what happens in isosmotic environment?
- balance. equilibrium of salt and water
46
what happens in hyper osmotic environment?
- cells shrink
- high solutes and low water
47
what does fresh water cause in plants?
- hydrostatic/ turgor pressure which prevents influx of water
- causes plant to be in hypotonic state
48
how does aquatic animals secrete ammonia (NH3)?
- diffuses ammonia into enviro (across body/gills)
- excretion in filtrate/urine
- ammonium (NH4+) and sodium exchange
49
How does terrestrial animals secrete ammonia (NH3)?
- Cannot use diffusion or ion exchange w/air
- only excretion in filtrate
- produces urea or uric acid
50
what is the first step of homeostasis by negative feedback?
1. change in internal or external enviro to produce physiological variable (ex. low body temp)
51
what is the second step of homeostasis by negative feedback?
2. change detected by specialized cells
52
what is the third step of homeostasis by negative feedback?
3. receptor (sensor) sends info along afferent (sensory) pathway
53
what is the fourth step of homeostasis by negative feedback?
integrator (specialized cell) receive sensory info and determine if action is required
54
what is the fifth step of homeostasis by negative feedback?
info is sent along an efferent (motor) pathway
55
what is the sixth step of homeostasis by negative feedback?
the effector receives info and produce compensatory change in physiological variable affected by enviro change (shivering)
56
what is the seventh step of homeostasis by negative feedback?
physiological actions of effector returns condition to desired levels
57
what is osmoconformer strategies?
- adjusts cells and extracellular fluid to match enviro [Y]=[X]=[Z]
- MARINE ANIMALS
58
what is osmoregulatory strategies?
- adjusts extracellular fluid to match cells and protect it from internal enviro
[X]=[Y] does not equal [Z]
- FRESHWATER FISH
59
what are some terrestrial challenges of water/salt ion loss and gain?
- water loss by dry enviro (water moving out
60
what are some aquatic challenges of water/salt ion loss and gain?
- marine animals = water loss (needs to limit urine and drink water ) (hyper osmotic)
- freshwater = water gain (needs to excrete large amount of diluted urine and drink little water) (hypoosmotic)
61
what is the terrestrial response to osmotic enviro?
- terrestrial = dry
- loss of water due to enviro so they need to consume/produce/conserve water
- limit salt intake
62
what is the marine response to osmotic enviro?
- hyper osmotic
- lose water and gains salt from enviro
- needs to eliminate salt (concentrated urine) and consume/produce/conserve water
- limit salt intake
63
what is the freshwater response to osmotic enviro?
- hyper osmotic
- gains water and loses salt
- eliminate water (dilute urine) and consume/conserve salt
- limit water intake
64
what is circulation?
bulk flow of fluid within body (water, solutes, nutrients, gases)
65
what is gas exchange
exchange of gases w/enviro
66
what is pH regulation
controlling [proton H+] of body fluids
67
how does circulation aid with transfer of solutes?
- via hormones, heat, gases, nutrients, etc
68
where does circulation happen in animals?
- in heterotrophs with digestive systems
- if they have high metabolic rates = rapid circulation
- cardiovascular sys= muscular pump + vessels
69
what is an open circulatory system
- pump moves hemolymph through sinuses in body tissues
- no distinction between hemolymph and interstitial fluid
- only pumps out
- not enclosed
70
what's a closed circulatory system
- moves in closed circuit
- blood is operated from interstitial fluid
- small diameter blood vessels exchange gases, nutrients, waste etc
- one direction
71
what does extracellular fluid (ECF) contain?
- plasma (water, ions, proteins, nutrients, gas)
- Key ions = Na, K, Cl, HCO3, Ca, H
- Key proteins = globulins, albumin, fibrinogens
- key gases = O2, CO2
- erythrocytes
- leukocytes
- platelets
72
what are erythrocytes
- contains respiratory pigments like haemoglobin and hemocyanin
- increases capacity of fluid to carry O2 and CO2
73
what does arteries do
- carries fluid AWAY from heart
- controls blood distribution to body by controlling vessel diameter
- takes pressure waves from heat and dampens them so they're not too intense
74
what does veins do
- carries fluid BACK to heart
- stores blood (easily expands)
- important for transportation, storage, exchange
75
what does the heart do
- muscular pump that uses energy to contract muscles
- maintains bulk flow of fluids in face of resistance (gravity)
76
what does capillaries do?
- exchange substances between blood + tissue (gas, fluids, solutes, nutrients, waste)
- promotes diffusion
- far from heart = high area = low velocity
77
what are single circuits
- 2 chambers
- one set of vessels
- limits metabolic rate (bc low pressure in systemic capillaries)
- lower efficiency
- mostly in fishes
78
what are double circuits
- 4 chambers
- 2 sets of vessels
- high BP from heart
- definitive split b/w oxygenated and deoxygenated blood
- most efficient
- birds and mammals
79
what are variable circuits
- 3 chambers
- no definitive split between oxygenated and deoxygenated blood (can mix)
- can shut iff circuit to lung capillaries
- variable efficiency
80
how do giraffes prevent hypertension?
- thick ventricle of heart w/o stiffening
- dense connective tissue in legs
81
why is gas exchange needed?
- kerb cycle and oxidative phosphorylation consumes O2 and releases CO2
- photosynthesis consumes CO2 and releases O2
- pH regulation uses CO2
82
how does ECF circulation help gas exchange?
- circulation moves ECF in animal (bulk flow) using muscular heat and blood vessels
- at the interface there is diffusion of capillaries
- needs small diameter
83
first step of ventilation
- bulk flow
- breathe in air and CO2 out
84
second step of ventilation
- O2 diffuses across respiratory surface and into blood
- CO2 diffuses out
85
third step of ventilation
- circulation by bulk flow
- O2 and CO2 transported by circulatory system to and away from cells
86
fourth step of ventilation
- diffusion between blood and cella
- O2 diffuses from blood into cells and CO2 diffuses out of cells into blood
87
humans breath uses what pressure
negative pressure
88
what does breathing involve?
- bulk flow between respiratory medium (air, water) and gas exchange surface (body surface/lungs/gills/etc)
- diffusion is too slow therefore we need ventilation
89
what is gas exchange
- diffusion between environment and ECF
- SA of gas exchange surface is proportional to mass and metabolic rate
- large animals needs specialized gas exchange structures
90
fick's diffusion law
Rate = (D) (A) dc/dx
d= diffusion coefficient
A= area of diffusion
C= change in [solutes]
X= thickness
91
what is countercurrent exchange
- less O2 available so takes more energy
1. fish opens mouth to take in water
2. water moves through gills (while it moves through, O2 gets absorbed)
- O2 and blood goes in opposite directions
- mose efficent
- diffusion
92
what is crosscurrent exchange
- air moves in one direction
- takes 2 cycle to move 1 unit of air (like pipette)
- more air moves to sack when inhaling
93
what is uniform pool?
- bidirectional, multidirectional flow
- takes 1 cycle to move 1 unit of air
- less efficient
94
what is pH
measure of [H+]
95
How does pH affect proteins?
- alters charge, protein shape
- affects solubility, function and enzymatic activity
96
CO2 + H2O <-> H2CO3 (carbonic acid) <-> HCO3- + H+
- high CO2 shifts equation to right to generate more H+ AND HCO3-
97
What are some buffering systems
- maintains pH
- Pulmonary
- Renal
- chemical buffering
98
what is pulmonary buffering system
- ventilation and respiration (TAKES MINUTES)
- second buffering system
- regulates CO2
99
what is renal buffering system
- excretion/diffusion of HCO3- or H+ (HOURS TO DAYS)
- last buffering sustem
100
what is chemical buffering system
- controls blood plasma (fast)
- first buffering system
101
what does respiration do
- regulates blood lvls of carbonic acid
- CO2 generated in cells increases concentration in blood
- CO2 gets diffused into erythrocytes where it combines w/hemoglobin to form HCO3- and H+
102
what does excretion (circulatory system) do>
- body getting rid of waste through urine to restore homeostasis
103
what happens when pH decreases?
1. brain stimulated
2. Respiratory rate increases
3. Blood CO2 levels decreases
4. Blood H2CO3 decreases
5. pH increases
104
what happens when pH increases
1. stimulates brain
2. Respiration rate decreases
3. blood CO2 lvl increases
4. Blood H2CO3 increases
5. pH decreases
105
compare animal and plant nutrients
- plants make their own food via photosynthesis
- animals need proteins
( need methionine -> cannot make our own so we need to eat plants)
106
explain plant nutrients: hydroponics experiment
- grew plants in solution then removed one nutrient at a time and observed growth
- result: deduces essential elements are
~ necessary for growth/reproduction
~ cannot be substituted
~ play roles in metabolism
~ plant dies if it was taken away
107
what does soil contain
- mineral particles, compounds, ions, decomposing organics, water, air, organisms
108
describe clay
- large SA to V ratio
- (-) charged so holds water easily
- water hardens clay making it difficult for plants to grow
109
describe sand
- large particles so water and nutrients drain faster
110
what is humus
- decomposing organics (usually on very top layer of soil)
- holds water and nutrients well)
111
what is passive transport
- no metabolic energy
- substance moves down concentration or electrochemical gradient
- simple diffusion of water, O2, CO2
112
what is active transport
- meeds metabolic energy (ATP)
- moves AGAINST gradient
- transports proteins using energy
113
what are essential elements for plants
- 17 essential elements
- macro and micro nutrients
114
what consists of macronutrients
- C, H, O from air and water (not minerals)
- N, P, K, S, Ca, Mg = minerals (in soil)
115
what consists of micronutrients
- CU2+, Cl-, Ni2+
116
what is chlorosis
yellowing of plant tisseues due to lack of chlorophyll
117
what is soil solution
- combo of water and dissolved substances that coat soil particles + fills pores
- available for plant after gravity drainage
- water molecules attracted by (-)ve clay + humus particles
118
what are some mechanisms to increase uptake of water and nutrients
- root hairs
- mycorrhizae
119
what does root hairs do
- if increased SA, more water and minerals absorbed
- no cuticle or stomata so they can be sponge-like
- charged particles that require own channel or transporter
120
what does mycorrhizae do
- mostly phosphate
- symbiotic relationship between fungus and plant roots
- plant give C to fungus
- fungus increases soil nutrients to plant
121
what are some Nitrogen limitation
- can't use bc lots are unread
- triple bond in N requires specific enzyme to break
122
what is the first step of nitrogen cycle
Nitrogen fixation
- converts atmospheric N2 into NH3 (AMMONIA) which dissolves to (AMMONIUM) NH4+
123
what is the second step of nitrogen cycle
ammonification
- breaks decaying organic N compounds into NH4+
124
what is the third step of nitrogen cycle
Nitrification oxidizes NH4+ to NO3-
125
what is the fourth step of nitrogen cycle
plant converts NO3- to NH4+ to assimilate N into organic compounds
126
how does minerals in soil enter plant?
- passively enter through roots along with water
- anions needs to be absorbed fast or else it will get washed away
127
what are some problems with N as fertilizer?
- causes eutrophication (grows algal blooms. once it dies it creates O2 taking bacteria)
- contributes to green house gases (N2O - nitrous oxide is worse than CO2)
128
describe the cation exchange
Mg2+, CA2+, K+ absorbed into (-)ve charged soil particles
- exchange replaces minerals w/H+ or carbonic acid
129
what happens in alkaline soil
anions leeched out easily
130
what happens in acidic soil>
cations leached out easily
131
what does short distance transport involve
- into and between cells
- to and from vascular tissues
132
what does long distance transport involve
- moves substances between roots and shoot parts
- 90% of water lost through transportation
133
what are 2 water transport ways
- apoplastic and symplastic pathways
134
what is a apoplastic pathway?
- water moves across outside membrane until it reaches endodermis (airport security)
135
What does the endodermis do
screens for impurities (only in apoplastic)
136
what is the symplastic pathway
- water goes through all cell layers Bia the plasmodesmata (connecting membrane between cells)
137
what is the nutrient movement?
- taken up from soil along with water
- both move in apoplast (passive uptake) and symplast (active uptake)
- endodermal cells = selective barrier
138
what is aquaporin
proteins allowing rapid movement of water through hydrophobic membrane core
139
what is water potential
potential energy of water (driving force)
140
what is the casparian strip
- root in endodermis forcing apoplectic water and nutrients into symplast
- ensures all water and solutes pass plasma membrane to enter vasculature
- restricts solutes from flowing back
- made of waxy substance
141
water potential equation
Ψ = Ψs (potential) + Ψp (pressure potential)
- Ψ of pure water = 0
- presence of solutes lowers water potential Ψs
142
what does the central vacuole do
- adjusts solute and water
- only in plants
- has tonoplast membrane that maintains turgor pressure
- high solutes = high pressure of system
- water always follows solutes
143
how does long distance travel work in xylem?
- cohesion-tension force
- root pressure
- stomata movement regulates loss of water by transpiration
144
cohesion-tension: root pressure
- (+) pressure in roots that forces xylem sap upwards
- occurs in high humidity or low light
- moves water short distance
- contributes to guttation
145
cohesion-tension: guttation
- when root pressure is strong enough to force water out of leaf openings
- water pushed up and out of veins
- only good in small plants
- in hot days, guard cells closed to prevent water loss
146
describe the pressure flow mechanism
- moving substances by bulk flow under pressure from source to sink
- based on water potential gradients
- load from source -> transport in sieve tube -> unload in sink
147
pressure flow mechanism steps
1. more [surose] in sieve tube brings water potential down
2. water from xylem enters sieve tube causing pressure to go up
3. sap flows in bulk to sink (lower pressure)
4. sucrose is unloaded into sink
5. water goes back to xylem via osmosis
148
what's transpiration
- evaporation of water through stomata pores
- cohesion-tension driven by transpiration
149
what is cohesion-tension
- h bonds of water help each other go up (cohesion)
- h bonds weakly attaches themselves to cell walls (adhesion)
-evaporation of one water molecule brings negative tension which creates negative pressure forcing another water molecule to go up
150
what is translocation
- long distance transport of substances via phloem (alive at maturity)
- multidirectional (xylem is unidirectional
151
what is phloem sap
- water and organic compounds moving through sieve tubes
- difference in pressure between source and sink regions drives flow)
152
what is a source
- region of plant where organic substances are LOADED into phloem
153
what is sink
- region of plant where organic substances are UNLOADED from phloem (mostly symplastic)
154
what is the phloem consist of?
- sieve tube and companion cell
- sieve tube can undergo partial cell death
- companion cell acts as side support that keeps sieve tube alive
- companion cell also converts simple sugars to complex sugars
155
how does CO2 and O2 get exchanged in plants?
through stomata
156
what is the stomata made of
- guard cells surround small pore (stomata)
157
stomata movement: transpiration-photosynthesis compromise
- balance of transpiration + gas exchange by opening/closing stomata as enviro changes
158
how is the stomata controlled?
- transported by K+ going in and out of cell
- stomata opens to photosynthesize (high blue light and low [CO2])
- Absicis acid (ABA)
159
How is transpiration regulated to prevent desiccation?
- cuticles limit water loss but prevents CO2 uptake
- Water always lost
160
what is abscisic acid (ABA)
- suppresses growth
- hormone signal for closure of stomata
161
open guard cell has what?
high K+
162
closed guard cell has what?
k+ needs to be pumped out (leading water to follow it and closing the guard cell)
163
what is Auxin
- promotes growth and elongation of cells
- governs response to light and gravity
- synthesized in shoot apical meristem and young stems + leaves
164
what is gibberellins
- stimulates growth + elongation of cells
- bolting: development of flowering stems
- fruit enlargement
165
what is cytokinins
- enhances growth and retard aging
166
what is ethylene
- gaseous hormone that regulates responses including senescence (cell stop growing)
167
what is Brassionosteriod
- regulates plant growth responses
168
what is Jasmonates
- regulates growth (also important for defence)
169
what is phototropism
- growth response to direction of light source
- blue light triggers auxin transport (elongation of cells
170
what is the acid-growth hypothesis
- where auxin pumps H+ out which activates the expansion to break cellulose
171
what is a hypersensitive response
- infected and uninfected cells around infection kills themselves to contain pathogen
- strengthens cell walls
- closes stomata
- selective plugging of xylem
172
what is systemic acquired response
- plant releasing signal to other plants telling that they were under attack so defend themselves
- this way other leaves don't have a hypersensitive response
173
how does tannins defend plants
- when plants are attacked, tannins are increase which makes plant bitter making insect top eating them
174
what are perfect flowers
both stamen and carpel on same flower
(both sexes on same flower)
eg. corn
175
what are imperfect flowers
- stamen or carpel ( not both)
- one sex
176
what is fission
parent splitting into two bodies
177
what is budding
parent grows cells that branch off
178
what is fragmentation
parent breaks part of themselves off
179
what is parthenogenesis
baby develops from unfertilized egg
180
pros of asexual reproduction
- reproduce in isolation
- reproduce rapidly
181
cons of asexual reproduction
- less/no genetic diversity
182
what is dioecious
- 2 houses (individuals produce one type of gamete)
- dad houses sperm; mom houses egg
183
what is monoecious
both egg and sperm in same body
eg clownfish
184
pros of sexual repro
- genetic variability
- more complex
185
cons of sexual repro
- slow ( courtship)
- energetically costly (to produce gametes, find mates, parental care, vulnerability to predation)
186
what is direct development
baby looks like tiny version of parent
187
what is indirect development
baby does not look like parent
eg tadpoles
188
what happens during fertilization
sperm and egg fuse to form zygote
189
what happens during cleavage
- zygote divides to morula then blastula
190
what is the morula
beginnings of body plan (symmetry)
191
what is the animal pole
cell divides to become animal
192
what is vegetal pole
becomes nutrients (yolk)
193
what happens during gastrulation
formation of echo/meso/endoderm, gut, mouth/anus
194
what are the 6 mechanism of gastrulation
1. mitosis
2. cell movement (cell moves to new position)
3. selective cell adhesion
4. induction (one group not cells influences other cells
5. determination (fate of tissues determinbed)
6. differentiation
195
what is spermatogenesis
- production of sperm
- specialized to move and penetrate egg
196
what is oogenesis
- production of ovum
- stores nutrients for early stages of development
- has protective coating
197
what happens during early stage of development
- produce zygote
- cleavage, blastula, gastrula (formation of tissue layers)
- chordate neurulation
198
what happens during external fertilization
- broadcast spawning
- many small gametes (low parental care)
-usually in sessile or marine animals
199
what happens during internal fertilization
- male deposits sperm into female
200
what is the acrosomal reaction
- fast reaction
- once sperm gets through egg, releases this response to prevent other sperm form entering
201
what is the cortical reaction
- slow
- egg creates thick layer around itself completely blocking other sperm
202
endoderm turns into what
digestive system
203
mesoderm turns into what
muslcles nd blood
204
ectoderm turns into what
skin, nervous system
205
what are the steps of chordate neurulation
1. notochord causes cells to thicken
2. cells sink and forms closed tube
3. edges fuse together closing the tube (spine)
4. migrating beiral cress cells becomes face
