BIol 371 Robinson lectures Animals Flashcards
What are the terrestrial lineages, what does terrestrial lineage mean?
Arthropods, such as insects, myria pods (centi and millipedes) and arachnids (spiders)
Vertebrates- reptiles
Amniote vertebrates- birds and mammals
Amphibians
What terrestrial lineage is still aquatic in its lifecycle?
Amphibians
What are the advantages to living in water?
Water supports the body
Reproduction is facilitated by flow, gametes don’t dry out-
Less fluctuation of temperature in water than in air
Metabolic wastes are removed easily
Sound transmits well
It limits metabolic rates
Explain why its a benefit that water supports the body
- water holds up body which is why we don’t see gelatinous zooplankton or jellyfish on land as there’s no medium there that will hold up their bodies.
Explain why its a benefit that reproduction is facilitated by flow
gametes don’t dry out- gametes can travel through water in order to reach their destination, water is a moist environment for them.
What are the advantages to living in water?
Water supports the body
Reproduction is facilitated by flow, gametes don’t dry out- gametes can travel through water in order to reach their destination, water is a moist environment for them.
Less fluctuation of temperature in water than in air
What are the advantages of water in removing metabolic wastes?
When aquatic organism makes waste, water dilutes it and carries it away. Land doesn’t have this easy way to dispose of waste.
What are the advantages of sound for aquatic organisms?
Sound is transmitted well in water, different in air
What are some disadvantages to living in water?
Density and viscosity of water causes cost of locomotion, visual range
Limits metabolic rates
Lower oxygen content
High thermal conductance
How is the density and viscosity of water a disadvantage?
As water is more dense and 50x more viscous than air, Takes a lot more energy to displace water than in air. Locomotion is much slower and energy consuming. Also is hard to see in.
How is the lower oxygen content in water a disadvantage?
Theres a low oxygen content in water, animals in water have to breathe more water than animals in air have to breathe air to get the same amnt of oxygen.
How is high thermal conductance a disadvantage?
Water heats up more quickly, means organisms will heat up more in water than air in warm temps.
What are challenges to living on land?
Desiccation- less liquid so there’s more chance of drying out
Temperature extremes- They are extreme on land more chance of freezing or boiling
Excretion- harder to remove waste from you
Reproduction- gametes can’t flow in water, easily dry out, need to find ways to travel without drying out in order to do external fertilization.
Locomotion- harder to move as water isn’t carrying you
Gas exchange- finish later
What are the four major challenges to living on land?
Dessication (not drying out)
Gravity- In an aquatic environment water is entirely supporting body, need structure to stop gravity from crushing you.
Breathing air- Breathing air is different than breathing water, more access to oxygen in air but need to convert it to work in a water based body.
Sensory systems and structures- There’s different sensory systems and structure made for air and water- challenge is taking information from out side body in air and translating that to water in the inside of the body.
How we do we avoid desiccation on land?
With mechanisms to reduce water loss and mechanisms to replace water loss
What are some mechanisms to reduce water loss?
Thick skin, waxy cuticle- is external structure which allows you to retain moisture
Behaviour- loss- for example some animals will avoid dry areas/dry habitats.
Produce concentrated urine (loop of Henle)- In the vertebrate kidney theres a loop of henle that reabsorbs water, want a longer henle if your in a dry environment in order to reabsorb more water and produce more concentrated urine.
What are some mechanisms to replace water loss?
We can drink and eat moist food
We have metabolic water that nourishes us, this water is produced by breaking of atp.
In kangaroo rats all of their water is produced by atp.
What is aestivation?
Is when organisms form a cocoon around themselves of mucus in order to tolerate desiccation during dry periods. Coccoon contains living tissues to prevent animal from getting sepsis and protect it from bacteria
What is an example of an animal that does aestivation?
African lung fish
Describe how rotifers adjust their reproduction in stressed vs unstressed enviroments
In unstressed environments (wet)- rotifers do asexual reproduction where a asexual female form a asexual egg which then also turns into a asexual female. The loop goes on and on.
In stressed environments (dry)- rotifers switch to sexual reproduction and do this by having the asexual female produce a asexual egg which forms into a sexual female that produces males through their unfertilized egg.
This male producing sexual female produces a meiotic egg which become a degenerate male, this male then copulates with the sexual female which results in a fertilized egg developing within the female, this zygote is resistant and can survive if the local water supply should dry up. The zygote stays dormant until conditions are favourable- this is when it is released to hatch in water and becomes an asexual female again.
In an environment are rotifers asexual or sexual?
Usually a mix of both, never one or the other
How can temperature extremes damage an animal?
Heat can denature proteins, extreme cold can make ice crystals in the cell and damage it’s functions
How do organisms deal with temp extremes?
Can avoid temp extremes by producing your own heat (thermoregulation)
Can avoid through behaviour- see animals that forage only during suitable temperatures.
Some animals do freeze avoidance, they lower the point that they can freeze at by concentrating their sugars.
Another way to avoid temp extremes, organisms use antifreeze proteins that bind with ice crystals make them small, and then cause less damage towards the cell. Do this by increasing phospholipids.
also do this through life cycle stages- through Hibernation, lowering metabolism through this in order to conserve energy in cold.
How do gametes avoid dessication?
they do internal fertilization- gametes enter body which is aqueous or stay in body in case of eggs.
How do embryos avoid dessication
Aquatic larvae- have embryo first develop in larvae so it can avoid dessication by living in water until adulthood.
Thick covering on eggs- turtles do this, do thick shells to protect embryo
Amniote (reptiles, birds, mammals) vertebrates surround embryo in
amniotic membrane- amniotic membranes can also create a fluid environment for a developing embryo
How do animals excrete waste in a way that they conserve water?
In terrestrial environments you want to discrete water w out losing a lot of water.
Production of nitrogenous waste is in the form of ammonia, this is toxic so having it be near the body and be concentrated is bad for animals.
To avoid this animals form substances out the water and create urea, which is less toxic and then can be exposed of at high concentration to avoid water loss.
Uric acid is less toxic than urea, is not soluble so it will ppt out of solution- lose little water in process. Is useful when retained in eggs, the formation of uric acid allows waste crystals to be isolated from the developing animals.
Why is a moist surface needed for gas exchange?
When breathing in o2 we need it to dissolve into and diffuse across membranes, dissolving the o2 in liquid allows this to happen.
Why is the gas exchange system internalized?
Is internalized to reduce water loss in mammals, allows them to conserve moisture as water isn’t released when gas exchange occurs.
How does the insect tracheal system reduce water loss?
Spiracles which are the small opening on the tip of the trachea (where gas exchange occurs) reduce water loss by opening and closing, so they only open when they need air and close when they need to conserve moisture
How do nasal passages in mammals reduce water loss?
The nasal passages are cool and extract water in the air exhaled through condensation.
Why is gas exchange better in air?
Air contains more oxygen, and oxygen can diffuse through air 10000x faster. Therefore easier to obtain o2 and do gas exchange.
Is sound faster in air or water?
400% Faster in water, higher pitched, has higher frequency, is louder
Is the speed of light better in air or water?
Iight is 25% slower in water so air.
How does olfaction work in mosquitoes?
The mosquitoes have hair-like structures on their antennae which they use to sniff out their hosts. The pores on these hair allow odor molecules to enter and transport through fluid and then bind to receptors sending the info to them.
What is an example of a organ that senses sound in insects?
The typanal organ, is a stretched membrane with air on both sides of it which detects vibrations using it.
What is an example of an organ that senses sound in humans?
The middle ear, is an air filled cavity, and the oval window is where vibrations in air are converted into vibrations in fluid, between the eardrum (air filled) and the oval window connecting to fluid filled- sounds are amplide by 20.
Where did our inner ear bones come from?
the reptilian jaw
How many ear bones do reptiles have?
one
How did eyes develop from going from water to land?
Increased in size which allows you to see much more on land and therefore catch more prey. In water increased eyes size doesn’t do anything as it’s hard to see. eyes shifted to top of head to let us aim eyesight for better hunting.
What would happen if limbs grew at the same rate the main body does?
The limbs would collapse as they can’t support that mass
Why does SA:V decrease as animals get larger
Because as animals increase in size its A^2, but volume increase triple that being A^3, SA doesn’t increase as fast as mass which means animals need other systems in order to suppot their increasing mass.
How does the skeleton change to support increased mass on land
The ribs become heavier and enclose to support lungs and organs, the spine develops to support limbs and now is attached to strong pelvic and pectoral girdles
How does stance change for bigger land animals?
Small animals have sprawled legs to support their lightweight, this is not good for large animals as it can’t support their weight so they have an erect stance.
What stance did the rauisuchians have?
pillar-erect, had femur sitting directly under pelvis- good as they were big animals and need support
What did dinosarus have to trade off in order to become bigger?
Agility, the larger and heavier you are the less agile you are
Can king kong support his mass?
No, as linear scaling of height doesn’t allow an organism to support it’s mass, need better structures in limbs to support
What’s the theoretical limit for an animals size?
100 tons
What does homeostasis mean?
Means one state, maintaining a steady internal environment- key as biochemical reactions are disturbed if homeostasis is not contained.
What cells face the environment?
External cells, are dead
Internalized external cells- for examples lung cells which are external but still face air from external environment.
ex: digestive cells bring the external environment inside- like the gut tract.
What are characteristics of external cells?
Have rapid turnover, make acidic environments (example acid in stomach) which are lethal to microbes, but also have mucus cells which protect the gut cells from the acidic environment .
What is the rate of diffusion?
Is the change in area time the change in concentration/change in distance
What is osmotic potential?
is the force driving osmosis, the potential of water molecules to move from a hypotonic solution to a hypertonic solution across a semi-permeable membrane
Solute moves from what conc to what conc?
Solute moves from high conc to low conc
How does water move in osmisis?
Water moves to area with high concentration of solutes and low water potential.
What does hyperosmotic mean?
It means a solution that is high in solutes, if a saltawter fish cell was placed in freshwater, that cell would be hyperosmotic to it’s surroundings.
What does hyposmotic mean?
A solution that is low in conc of solutes.
What does isoosmotic mean?
solutions with the same concentration of solutes
How does osmolarity affect animal cells?
Cells will shrink or swell if not maintained isoosmotic, for example if there’s a lot of solutes in the cell water will rush in causing it to swell.
How does osmolarity affect plant cells?
Cell develop turgor pressure when there’s more solutes inside them compared to outside of them, this stops further water from entering the cell.
What are Osmoconformers? Give examples
These are organisms that maintain their internal environment to be isoosmotic to the external environment.
ex: marine inverts, hagfish, elasmobranchs
How do osmoconformers keep themselves isoosmotic?
They adjust the osmotic strength of their cells and extracellular fluid to match the environment.
What are osmoregulators?
They maintain their internal osmarility.
ex: freshwater inverts and most vertebrates
How do osmoregulators work?
Adjust osmotic strength of extracellular
fluid [X] to match cells [Y] and protect the
internal environment from the external [Z]
How do terrestrial animals, aquatic animals, and freshwater animals behave in terms of water/salt loss and gain?
Terrestrial animals lose water to their external dry environment.
Marine animals lose water as the solute concentration of salt water is high, however they gain salt as salt conc is lower in their internal environment.
Fresh water animals gain water as the solute conc on fresh water is very low compared to their internal environment, however they lose salt as fresh water has none.
How do seagulls get rid of extra salt?
Via salt glands, they release their concentrated salt through their beak and nostrils which these salt glands are connected to.
How do animals responds to terrestrial environments in terms of osmosis?
Terrestrial environments are dry:
* lose water to the environment
consume/produce/conserve water
limit salt intake
How do animals respond to hyperosmotic environments?
lose water to and gain salt from the
environment
eliminate salt and consume/produce/conserve
water
limit salt intake
How do animals responds to hypoosmotic environments?
Gain water from and lose salt to the
environment
eliminate water and consume/conserve salt
limit water intake
How does excretion work as
mechanism for
osmoregulation?
Eliminates waste/toxins and aids in controlling content of extracellular fluid such as controlling salt.
What four things do excretory organs do?
Do Filtration- filtrates blood by passing it through narrow spaces between cells (isoosmotic)
Reabsorption (selective)- Removes the useful solute from the filtrate and puts them back in the blood via tubules. When water is removed here it’s hyperosmotic.
Secretion (selective)- takes additonal waste and puts in filtrate by putting it back in tubule. (hyperosmotic)
The waste products and some water are finally excreted and put into environment (piss).
How do aquatic organisms get rid of ammonia?
They diffuse it into the environment via their body and gills, excrete it in filtrate/urine, or they exchange it with sodium across the plasma membrane,
How do terrestrial ( and few aquatic) organisms secrete ammonia?
Can’t do it via ion exchange or diffuse it out, they can only do it via filtrate.
Do it by producing urea or uric acid
How do migratory salmon maintain osmoregularity as they change environments a lot?
they do it via ion exchange by pumping salt out of body or do it via their kidneys by producing dilute pee or concentrated pee.
How do marine mammals maintain osmoregularity?
Gain metabolic water by eating food
Why do we circulate fluids in the body?
Because cells can’t move so we need fluid to move around to main osmolarity, pH, get rid of waste, and to also transport nutrients, solutes, hormones and to communicate to the body
Is diffusion an acceptable way to circulate fluids in larger organisms?
No! Some cells lie too deep in the body
How do animals circulate fluids?
Through open or closed circulatory systems
What is a open circulatory system?
Fluid, which is referred to as hemolymph is not contained in the blood vessels, there’s no difference between it and the interstitial fluids, it bathes the cells.
As most pressure comes from blood vessels, and this system doesn’t have vessels, the blood pressure is reduced and it takes a longer time for oxygen to reach the cells which results in a lower metabolic rate overall.
What is a closed circulatory system?
Fluid is blood and is contained/flows in blood vessels where exchange of gasses, nutrients, and wastes take place.
What is blood?
is extra cellular fluid contained in vessels, has both a fluid and cells in it.
The ECF that is blood contains what?
Plasma
Red blood cells (erythrocytes)
Leukocytes (white blood cells)
Platelets
What is plasma composed of?
fluid component- Plasma (water, ions, proteins, nutrients, gas)
Key ions are Na, K, Cl, HCO3, Ca, H
Key proteins are globulins (bind to lipids), albumin, fibrinogens
Key gases are O2 and CO2
What is erythrocytes composed of? wHAT DO THEY DO?
contain respiratory pigments –
haemoglobin, haemocyanin, etc.)
Increase capacity of fluid to carry O2 and CO2
What do leukocytes do?
are part of immune system
What are platelets?
A tiny, disc-shaped piece of cell that is found in the blood and spleen. Platelets are pieces of very large cells in the bone marrow called megakaryocytes. They help form blood clots to slow or stop bleeding and to help wounds heal
How does the heart work?
Is a muscular pump and generate pressure to move fluid around the body. Sends blood out at high pressure, recieves blood at a low pressure.
Why does the heart maintain bulk flow?
When met with resistance in blood vessels which decreases flow according to ohms law, the heart maintains bulk flow by elevating the pressure of the blood again to move it through the system once more
What are blood vessels important for?
transportation, storage and exchange
What three types of blood vessels are there?
Arteries, veins, and capillaries
What do arteries do?
Carry fluid away from heart, are elastic so they contract to increase resistance and therefore slow blood flow. This depulses pressure waves from the beating heart.
What do veins do?
Carry fluid back to the heart, and store blood by expanding.
During exercise they contract to help move blood back to the heart.
What do capillaries do?
Capillaries sit between the arteries and veins, they help exchange substances between blood and tissues by diffusion- do this when flow is slowed down as it allows time for it.
How and why do giraffes handle having very high blood pressure
Need high blood pressure in order to get blood to brain which is far away from heart, do this by having thick ventricles in the heart which can withstand high blood pressure, and have dense connective tissue in legs to stop blood from pooling in them and slowing down blood pressure and not being able to circulate back to the heart.
Why is gas exchange needed?
needs krebs cycle and ox phos to produce co2, need plant to consume co2 and give o2, need it for co2 regulation to regulate carbonic acid formation, need it for both plants and animals to breathe
Why is co2 build up bad?
Can produce bad effects like stopping atp production
