bio exam 2

(plant cells)the more solute an are has the lower the water potential, explain why?

(Plant cells)Solute potential is when the solute potential of pure water is zero. Adding solutes lowers the water potential; the higher the solute concentration the lower(more negative) the solute potential.

Explain and define Evolutionary adaption and physiological/behavioral adjustmentswith pigeon example. and how the latter helps maintain homeostasis.

-Evolutionary adaptions happen across generations for example: evolution of insulating feathers down on body in birds living in cold climates. - physiological/behavioral adjustments occur over the time scale of the individual organism's lifetime (often much shorter than that) via • reversible changes at the individual level • do not involve changes in allele frequency in a population. - its a short term homeostatic mechanism that occur when there's seasonal changes in physiology or behavior, other times there's long term responses to altered environment. Example: changes in position of feathers (fluffed up vs flat) in a bird to facilitate cooling or heat retention

explain how organisms can either regulate their body temperature physiologically or not? what do they do instead to regulate body temp? give examples.

1)regulate body temperature physiologically so that they are relatively unaffected by the ambient environment and can therefore live under a wide variety of conditions. Typical of most animals.or2) do not regulate temperature physiologically and accept the metabolic consequences or live under a narrow range of conditions. - Is typical of other animals, plants, microbes, and fungi, although all of these exhibit some strategies for avoiding or coping with extreme temperatures.Temperature

According to a major scientific principle called the law of conservation of energy (or the second law of thermodynamics), energy cannot be created or destroyed. However, energy can be transformed. Summarize some of the energy transformations described in the paragraphs above. Both ectotherms and endotherms generate some heat by breaking down food.

An organism can convert potential energy in food into kinetic energy / heat in muscles. Food is broken down by cellular respiration to produce cellular energy in the form of ATP. ATP is used for all types of biological "work," such as growth, movement, and reproduction. During cellular respiration, some of the chemical energy from food is also converted into heat.

An average adult cheetah has a metabolic mass of 44,010 grams and a resting metabolic rate of 61.77 joules per second. Use this information to add a data point for the cheetah to Figure 2. Based on these data, would you characterize the cheetah as an ectotherm or endotherm?

Based on this data, we would characterize the cheetah as an endotherm - the data point for the cheetah would be at around the same position as the point for the dog or the kangaroo, which are both endotherms.

why is countercurrent exchange important for more than extracting oxygen into the blood vessels.

Countercurrent heat exchange also occurs because of the close proximity of the vessels, this allows for heat exchange. in the example of the webbed bird leg, the blood vessels allow for heat exchange and also creates a gradient because the heat energy can move from where its high to where its low. blood flows in the opposite direction in countercurrent flow so in the example of the bird, standing on ice, the blood vessels are really close to one another so they exchange heat. would be colder as it flows towards the feet, but as it comes back up to the body, the blood gets warmer again to prevent from chilling ht internal organs..

Which types of animals have the highest mass-independent growth rates? Which have the lowest?

Endotherms have the highest growth rates and ectotherms have the lowest.

What is the difference between Evolutionary Adaptions vs. Behavioral/ Physiological Adjustment?

Evolutionary changes are genetic changes across generations and physiological/behavioral adjustments are short term reversible non-genetic changes.

Control of cell volume in Animals. what is extracellular fluid? is it inside the cell? what is its purpose

Extracellular fluid is liquid outside of the cell that is isotonic to intracellular fluid(inside the cell. the body needs to maintain appropriate water content within the cell, the blood and the extracellular fluid. ion something is passing through it will come through he extracellular fluid and then move into the intracellular fluid.

In general, as metabolic rate increases, how does growth rate change?

Growth rate positively correlated with metabolic rate.

Halophytic plants, such as mangroves, are able to grow in salty habitats, includingcoastal salt marshes. Thinking in terms of water potential, why would plants growing insalty habitats have difficulty in taking up water?

Halophytic plants would have to overcome the large negative water potential of saltwater, or salt saturated soils, in order to move water into their cells. If students ask howthey can do this, here are some adaptations that halophytic plants use.-sequestration of ions in their vacuoles to increase the solute concentration of cells-partitioning toxic ions into leaves to increase the solute concentration of cells-active excretion of salt from root or leaf surfaces-accumulation of salt in surface glands that break off or burst harmlessly-restricting entry of certain ions at the roots

How do animals that hibernate regulate their body temperature? What are they called? use ground hogs as example

Heterotherms exhibit both endotherm and exotherm behavior where they actively regulate their body temp when they are night hibernating but when they are, they use the external environment for energy. some animals that hibernate lower their metabolic state and regulation.

maintaining a a steady state through behavioral and physiological responses is the definition of , give an example and explain including negative and positive feedback using examples..

Homeostasis, in homeostasis there is negative and positive feedback which are used in physiological and behavioral systems. Negative feedback uses mechanisms where if any changes occur in the organisms homeostasis, certain mechanisms brings the organism back to a particular set point. - in positive feedback, you want things to keep going so you accelerate a current trend. ex. blood clotting - Injury to the lining of a blood vessel exposes collagen fibers. Platelets adhere to these fibers.Platelets release chemicals that make nearby platelets sticky. more platelets are released until its done

the internal and external environment of organisms is constantly changing, yet to survive, organisms must operate within certain physiological parameters. How do you keep your body at somewhat of a study state when everything around you is changing?

Homeostasis: The regulation and maintenance, in organisms,organs or cells, of a stable, internal physiological state in the face of a changing external environment - Temperature Regulation• -Water balance - Hormone levels -Glucose levels• -pH levels

Explain Hypertonic, Isotonic and Hypotonic in your own words and the consequences of water loos and gain in the animal

Hyper-too much water outside the cell Hypo- too much water in the cell Iso- equivalent amount of water in and out of the cell.

What is transpiration?

I.Water is passively transported into the roots and then into the xylem. The forces of cohesion and adhesion cause the water molecules to form a column in tube shaped cells called xylem. Water moves from the xylem into the mesophyll cells, evaporates from the leaf surface and leaves the plant by diffusion through pores non the leaves called the stomata. *there's more stomata at the bottom of leaves.

. How do the metabolic rates of both ectotherms and endotherms vary with mass?

In general, as mass increases, the metabolic rate of the organism also increases.

How do the metabolic rates of ectotherms compare with those of endotherms of similar mass?

In general, endotherms have a higher resting metabolic therms compared to ectotherms of the same mass.

what are the two additional components of water potential? Which is the result of adhesive forces that binds water to physical objects such as soil particles or cell walls, and which is the result from the pressure of gravity on water

Matric potential and gravitational potential. Matric potential is negative and has hydrophilic properties of soil particles and plant cell walls pull on water molecules) Gravitational potential is negative, the force of gravity pulls down on water molecules. *Plants must overcome the negative forces of gravity potential (Ψg) and matric potential (Ψm) to maintain a positive pressure potential.

We could see if the cheetahs metabolic rate decrease as temperature increases from 0 degrees celsius (endotherm), or if the cheetahs metabolic rate increases as temperature increase then the cheetah could be a ectotherm since they expend more energy as it becomes available with temperature rises.

Metabolic rates tend to increase with mass for both endotherms and ectotherms.

what kind of feedback occurs during breastfeeding?

Positive feedback stimulus- baby suckles at breast Receptor: sensory receptors in the skin of the breast detect the suckling;send impulses to the hypothalamus Control center: hypothalamus signals t the posterior pituitary to release oxytocin - oxytocin is released Effector- breast is stimulated to eject milk -Breast milk is released.

When the cell walls push back on the water, what do we call it? *hint: its positive.

Pressure potential is when cells take up water, they swell, but the cell walls provide resistance which produces a pressure potential(greater pressure inside cell than out). This pressure is positive because we are pushing not suctioning.

how do endotherms generate heat by shivering?

Shivering rapidly contracts the muscle fibers to use energy and produce heat. Making a lot of heat — plus having insulating fur, feathers, or clothes — keeps endotherms warm in cold environments.

why do we care about our temperature?

Temperature affects the rates of biochemical reactions which are catalyzed by enzymes, protein function and membrane structure• Temperature increases molecular motion and the rate of reactions• Enzymes have specific temperature ranges for optimum performance• Proteins can become denatured at high temperatures• Membranes can become more rigid at low temperatures or leaky at high temperaturesMetabolism produces heat; getting rid of heat becomes a problem for larger organisms Babies cannot shiver so they have a special tissue called brown fat which generates heat

Explain why a mouse (an endotherm) would probably have wider bone rings than a similarly sized lizard (an ectotherm).

The mouse will have a higher metabolic rate to regulate its temperature increase the lizard will use external energy to regulate its temperature and thus will not have as high of a metabolic rate.

Many grasses, especially those from arid environments, roll their leaves into narrowcylinders when facing water stress. Why don't they keep their leaves rolled all of thetime, if that helps to limit water loss?

The smaller leaf surface area exposed to the atmosphere would limit the amount ofcarbon dioxide plants would be able to take up through their stomata.

lipids present several challenges in digestion what do we know that they do to be challenging

They are hydrophobic so they clump together - not water soluble fatty foods don't get broken down in the stomach they go to the small intestine

inside leaves there's quite a bit of air space, why?

To help diffuse a carbon dioxide into their leaves

Total Water potential has two essential component, what is water potential made up of?

Water potential is the sum of both solute potential(how concentrated the solutes are in t he cell) and pressure potential.(push back of cell walls)

Briefly describe other data you could collect to provide additional evidence for whether the cheetah is an ectotherm or an endotherm.

We could see if the cheetahs metabolic rate decrease as temperature increases from 0 degrees celsius (endotherm), or if the cheetahs metabolic rate increases as temperature increase then the cheetah could be a ectotherm since they expend more energy as it becomes available with temperature rises.

when parietal cells use AT THIS POINT driven pumps to expel Hydrogen into the lumen of the gastric gland what does it do?

chloride ions diffuse into the lumen through the membrane channels. only in the lumen do the H+ and CL- come together to form Hydrochloric acid.

Define "ectotherm" and "endotherm" in your own words. List four examples of animals that would fit into each category.

ectotherms are animals that rely on the external environment to regulate their body temperature and endotherms use their metabolic energy to regulate their body temperature so their body temp could be complete different to the environment around them where as in ectotherms their body temperature is linear to the environment.

Ectotherms regulate their body temp through external energy sources give an example of how they do this, what kind of animals

ectotherms are mainly reptiles, fish and invertebrates, they regulate their body temperature through the external environment such as hiding under rocks and such. to cool down. they use energy from the environment.

how do lizards stay alive when the temp gets hot?

ectotherms use behaviors and takes advantage of its environments, it has its habitat, during the day the lizards body temp fluctuates within a range, when it gets too hot, it can go into shade to cool down and come back out, it can choose when to get energy, this is behavioral. ectotherms regulate their body temperatures but not with metabolic energy.

who has a higher metabolic rate endotherms or ectotherms? what does this allow them to do?

endotherms tend to have higher metabolic rates than ectotherms, they are generally more active, grow and reproduce faster, and thrive over a wide range of temperatures. However, endotherms must also eat much more often and are more likely to run out of food. A shrew (a small endotherm similar to a mouse) may starve to death in a day without food. A similarly sized lizard (an ectotherm), on the other hand, could go without food for several weeks.

the initial molar concentration of the cytoplasm inside a cell is 2M and the cell is placed in a solution with a concentration of 2.5M. Initially, the numerical value of the solute potential is more negative inside the cell than outside true or false

false bc the solute potential is lower outside the cell

The initial molar concentration of the cytoplasm inside a cell is 2M and the cell is placed in a solution with a concentration of 2.5M. Water will enter the cell because solute potential is lower inside the cell than outside. true or false

false because there is a higher concentration outside of the cell meaning that water will flow out of the cell and solute potential will be lower outside the cell because when solute concentration is high, solute potential is low.

How does osmoregulation work in salt and fresh water fish

for fresh water fish, the cells inside will have a higher concentration so by diffusion water will keep going in and salt will leave by diffusion.They make a lot of dilute urine to maintain salt and water diffusion. They drink little water but get their ions from food, they get sodium potassium and chloride from food. in skin they have a passive transport of ions. - marine fish pee very little but its more concentrated, they transport ions out through their gills, they have to do that because the ions keep coming back in when they eat and when they drink water, and also just through passive transport(loose water through their skin)

What are essential amino acids?what amino acids do we get from food?

histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine

Cavitation

is when a plant cannot supply its xylem with adequate water so instead of being filled with water the xylem gets an air bubble or embolism.(bubble in the xylem) freezing and thawing can create air bubbles because the solubility of gas in ice is very low.

what does the mucous cells do?

it stops the hydrochloric acid from getting through. it coats the inside of the stomach they expel chloride ions into the cell separately because you don't want it in the cell you only want it in the lumen

what type of feedback occurs in the regulation of blood glucose levels?

negative feedback because blood glucose levels;s rises after eating and because of homeostasis when the blood glucose level drops below a set point the pancreas releases a different hormone that then causes the liver yo break down glycogen into glucose.

Explain positive feedback with the example of a pregnant woman going into labor

positive feedback because we are trying to accelerate the rate of which she is pushing the baby out so that she can stop once the baby is born.

what is the body temperature regulation of a red panda? explain how this is done.

red panda's are Endotherms like mammals and birds. Endotherms use a lot of metabolic energy and physiological mechanisms to regulate body temperature

How does our body break down foods?

stomach has special chemicals that allow it to not break down the tissues of itself

How does temperature regulation function, what happens if temperature is too high?if too low? explain example of babies and how they keep warm.

temperature affects the rates of biochemical reactions which are catalyzed by enzymes, protein function and membranes structure.

Xylem is a straw for the plants explain

the cell walls form these straw like shapes called tracheas

where does carbon dioxide come in through in a plant? where does water come up from?

the leaves, carbon dioxide diffuses more slowly in water than air - root-stem- leaves-air

how do we break down these large lipids into smaller pieces cover more surface area?

the liver makes bile that's stored in the gallbladder, bile is released into the small intestine and it had a hydrophilic end attracted to the

water potential

the potential energy of water?By definition, the water potential of pure water is zero. Any solution with a water potential of less than zero has a tendency to take up water from pure water. the soil has the highest water potential. water goes from the roots -stem- leaves- air

where is surface are important in plants

the roots because it controls how much water is taken up and the leaves because it controls how much water comes out.

In ectotherms and metabolic rate

their metabolic rate increases as temperature increases because it increases the rate of enzymatic reactions within them, so they will be able to do more in warmer temperatures, they aren't using that energy to regulate anything just to do more things.(act faster).

To survive, most animals regulate their body temperatures to keep them within a certain range. The process of regulating body temperature is called

thermoregulation

changes that occur in anticipation of something that going to happen, what is this the definition of and give an example

this is feedforward, so for example shivering is a feedforward method- physiological response in preparation. same example is dog salivating before eating for dog.

Why does chloroplasts need to be near air spaces

to assimilate to co2,if chloroplasts are exposed directly to air they will lose too much water and potentially die

The initial molar concentration of the cytoplasm inside a cell is 1.3 M and the surrounding solution is 0.3M. If the cell reaches equilibrium with its surroundings, there must be pressure potential inside the cell.

true, solute potential is negative but once its at full turgor the=an the water potential is zero, to be equal the cell wall will have to have a positive pressure potential. pressure potential's always positive squeezes the water out.(pushing force)

how can a plant let co2 in without letting water out?

water can't get through the waxy covering called cutin however the stomata lets out water, in most plants stoamata is open during the day when lights available for photosynthesis. The can control the solute inter cells.

Because of the concentration of sodium and chloride inside of your cells there's a leakage of (sodium)Na+ and Cl- into the cells down their concentration gradient. what would happen if we had sodium and chloride keep coming into the cell.

water will come in through tis concentration gradient because the more concentrated a cell is the more water will come thru to dilute it. - if too many solutes enter the cell then the cytosolic solute concentration would increase causing an influx of water and cell lysis.

water is sucked up because of suction from the air, it doesn't fall because of cohesion and tension. what is cohesion and adhesion

when alike molecules stick together and disalike molecules stick together

why does the chief cells release pepsin into the lumen?when does this occur?

when pepsinogen is in the presence of hydrochloric acid it cleaves of a chloride ion and activates it to break down a protein called pepsin, this only occurs when there's food indoor stomach. pepsin can activated in two ways, HCL and pepsinogen itself.

How would we remove sodium from the cell? we are using the sodium potassium pump, what will it do?

when protein is a pump it requires energy, and so if there is too much sodium inside of the cytoplasm and potassium is low, sodium is going to keep coming into the cell so sodium binds to the sodium potassium pump which stimulates the phosphorylation of AT THIS POINT. this causes the conformation of the protein to change its shape and expel sodium out. on another site potassium in the extracellular fluid binds to the pump and triggers the release of phosphate group. this restores the original conformation and potassium is released inside and sodium is receptive again.

how can we predict where water will go?

will go to whatever is more negative, so wherever water potential is low Whenever water moves by osmosis, it moves across a semipermeable membrane toward the region of lower (more negative) water potential. Thus, if the left-hand side above is negative, then water is moving into the plant cell.