2.D.4

Essential knowledge 2.D.1: All biological systems from cells and organisms to

populations, communities and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy.

1.Provide examples of how biotic and abiotic factors affect organism behavior,

community interactions, and ecosystem structure. Utilize the following examples

in your responses:

○ Water availability

If there is not enough water in a environment (abiotic), then the organisms living there will die.

○ Sunlight

Plants (biotic) that receive little to no sunlight (abiotic) will die because they cannot undergo photosynthesis. 

○ Symbiosis (mutualism, commensalism, parasitism)

Symbiosis; Clown fish are protected by the anemone.

Mutualism: Bees pollinating a plant, both benefit

Commensalism: Barnacles living on a whale, one is benefiting but neither hurts the other.

Parasitism: Tapeworms living inside of a human, the parasite ( tapeworm) is receiving nourishment from the host.

○ Predator–prey relationships

A mongoose eating a snake is a example of a predator-prey relationship.

○ Water and nutrient availability, temperature, salinity, pH

If there is low resources and water (abiotic), then organisms in a environment will die

○ Availability of nesting materials and sites

If birds want to nest on a cliff (biotic), the geography (abiotic) may not be large enough to support all of the birds.

○ Food chains and food webs

If wolves were moved from a ecosystem, then the populations of the surrounding organisms like beavers, foxes, and trees would decrease or increase dramatically

○ Species diversity

In a diverse ecosystem, if you remove a species from a environment, then populations of other species will be greatly effected.

○ Population density

If there are is a large amount of fish in a small lake, then the fish will have to compete with the other fish for the limited resources.

○ Algal blooms

In the St. Johns river, the water is warm and the sunlight is abundant and causes alga to boom and massive fish die off during the night because there is not enough of water of oxygen

Essential knowledge 2.D.2: Homeostatic mechanisms reflect both common

ancestry and divergence due to adaptation in different environments.

1.     How do homeostatic mechanisms relate to evolution?

Homeostatic mechanisms relate to evolution because they reflect a common ancestry in all organisms

2. How is the concept of common ancestry supposed by continuity in homeostatic

mechanisms.

The concept of common ancestry is supported by continuity in homeostatic mechanisms because every organism has a response but they have different responses to different environmental conditions

2.     How do changes in environmental conditions affect this continuity.

Changes in a environmental condition affects continuity by how a organism responds to that condition

4. Explain how the following mechanisms are used for obtaining nutrients and eliminating wastes.

 

Flatworm excretory system

Stomata

○ Gas exchange in aquatic and terrestrial plants

Both aquatic and terrestrial plants both use gas exchange by diffusion however both of them have a different way of acquiring water. In terrestrial plants get water through openings called stomata, while aquatic plants exchange gas through direct diffusion in surrounding water.

○ Digestive mechanisms in animals such as food vacuoles, gastrovascular cavities, one-way digestive systems

Protists take food in through phagocytosis and store the food in a food vacuole. In a gastro vascular system, there is one opening that take nutrients and gases from the environment. A one-way digestive system there is one opening for food and another opening for waste.

○ Respiratory systems of aquatic and terrestrial animals

Lungs

In aquatic animals, gills are used to filter water and for the animal to get oxygen. In land animals, oxygen enters the body through tubes in insets, vertebrates have internal lungs and mammals and amphibians use positive pressure breathing to force air down the trachea.

○ Nitrogenous waste production and elimination in aquatic and terrestrial animals

All organisms produce and eliminate waste in aquatic and terrestrial animals.

5. Explain how homeostatic control systems in species of microbes, plants an animals support common ancestry. Use the following to help illustrate your explanation:

○ Excretory systems in flatworms, earthworms and vertebrates

Flat worms regulate the excretory system by protonephridia. They are branching canals that allow waste out of their body. Earth worms go through metanephridia to release toxic urea. Vertebrates use kidneys to release waste.  Shows that all organisms release waste

○ Osmoregulation in bacteria, fish and protists

Osmoregulation shows that all organisms go through this process.

○ Osmoregulation in aquatic and terrestrial plants

Both plants and animals have openings to balance gas

○ Circulatory systems in fish, amphibians and mammals

All organisms need to transport nutrients through blood to all their cells

○ Thermoregulation in aquatic and terrestrial animals (countercurrent exchange)

All organisms need a flow to keep homeostasis in their body

Essential knowledge 2.D.3: Biological systems are affected by disruptions to their dynamic homeostasis.

1. How do disruptions at the molecular and cellular levels affect the health of the organism? Use the following to explain your answer:

○ Physiological responses to toxic substances

Organisms that are expose to toxins in food, water, or in the air can be affected by causing cancer in organisms and can threaten wildlife.

○ Dehydration

If a organism undergoes dehydration, the organism can experience darker urine, respiration increase, delirium and then death.

○ Immunological responses to pathogens, toxins and allergens

If a organism is not able to fight off an infection, such as a person having HIV, then any pathogen can invade the body and the body will not respond to the pathogen.

2. Provide examples of how disruptions to ecosystems can affect the dynamics of the  ecosystem. Utilize the following examples in your responses:

● Invasive and/or eruptive species

An invasive species can cause other species in the environment to start to compete with aggressive species for resources

● Human impact

Farmland can reduce biological activity

● Hurricanes, floods, earthquakes, volcanoes, fires

Natural disasters can disrupt a ecosystem by killing trees, organisms, and reducing resources in a ecosystem

● Water limitation

Limited water will cause organisms to compete with each other and can cause death to those that aren’t fit enough.

● Salination

If a soil does not have a proper amount of nutrients, then plants will grow slowly or will not be able to live in that environment

Essential knowledge 2.D.4: Plants and animals have a variety of chemical

defenses against infections that affect dynamic homeostasis.

1.     Explain how plants, invertebrates and vertebrates have multiple, nonspecific (innate) immune responses. Include how they work and structures/chemicals involved.

Invertebrates use their exoskeleton and the digestive system to fight off pathogens. Hemocytes are found in hemolymh of insects. They engulf pathogens through phagocytosis. Plants use PRRs that detect microorganism associated molecular patterns (MAMPs). Once the PRRs have detected MAMPS they will begin systemic acquired resistance and destroy infect and adjacent cells. Vertebrates have multiple types of non-specific responses such as skin, mucus and lysozymes. These responses stop pathogens from entering the body and lysozymes.

2. Describe mammalian specific immune responses.

• Describe the two types of specific responses in the Mammalian

immune system

• In the cell-mediated response, what is the role of cytotoxic T cells?

• In the humoral response, what is the role of B cells?

In cell mediated response cytoxic T cells attach to a pathogen and turn into a killer T cell, which will kill the pathogen. In the humoral response, B cells create antibodies to shut down a pathogen so a macrophage could digest it.

3. Explain how antigens and antibodies work together.

• What is an antibody?

• How does a second exposure to an antigen differ from the primary exposure?

An antibody is Y shaped protein that identifies and neutralizes pathogens.  If a person was exposed to the antigen a second time, Memory cells would know what the specific antigen is an will be able to clone B and T cells much faster than in a primary exposure

2.C.2

Feedback mechanisms

2.C.1 – Organisms use feedback mechanisms to maintain their internal environments and respond to external environmental changes.

·      Discuss how negative feedback works. Discuss the following two examples – Thermoregulation in animals and plant responses to water limitations.

Negative feedback is a mechanism that maintains dynamic homeostasis by returning a changed condition set to its target set point. ­­­­­­An example of negative feedback is thermoregulation in animals. The central thermo receptors in your body respond to a change in your body temperature by either releasing sweat to reduces heat in your body, or shiver and your skin will get goose bumps to contain heat and produce heat to bring your body temp to its set point. Another example in plants is its responses to water limitation. If a plant has a low supply of H20 in in its system it can create a acid that will close the stomata so little water is lost.

·      Discuss how positive feedback works. Discuss the following three examples – lactation in mammals, onset of labor in childbirth, and ripening of fruit.

Positive feedback is a mechanism that amplifies  responses. Three examples of positive feedbacks are lactation in mammals, onset of labor in childbirth, and ripening of fruit. In lactation, sucking stimulates cause nerves to tell the hypothalamus to create Oxytocin which in term creates milk. In childbirth, the head of the baby is presses against the cervix and causes nerve impulses to stimulate a pituitary glad to secrete oxytocin and causes the uterine to contact to push the baby out towards the cervix. When fruit is ripe. A chemical called ethylene is produced by the fruit, which acts as a chain reaction towards other fruit and makes them produce ethylene

·      Discuss how an alteration in the mechanism of feedback can result in dire consequences by using the following three examples: diabetes mellitus in response to decreased insulin, dehydration in response to decreased antidiuretic hormone and Grave’s disease.

Diabetes mellitus is a example of an alteration in a feedback mechanism because in type 1 diabetes, the pancreas is unable to create insulin and results in high blood sugar if not monitored due to a autoimmune disease to insulin. Type 2 diabetes is a alteration in a feedback caused by an unhealthy diet and also results in cells not producing insulin because the cell producing insulin stop production. Some people are unable to produce the hormone, antidiuretic and one of the side effects is grave disease. Grave disease is the result of no antidiuretic hormone and causes a persons eyes to hyperthyroid.

2.C.2 – Organisms respond to changes in their external environments.

·      Discuss how organism respond to changes in their environment by using the following examples:

o   Photoperiodism and phototropism

Photoperiodism is a physical response in plants that results in flowering. The photoperiod of the plant, which is the length of night and day so the plant knows what time of year it is. Is regulated by a phytochrome. A phytochrome is ultimately that makes a plant flower. 

o   Hibernation and migration in animals

Hibernation and migration are both results of a change in conditions. Hibernation is a state of inactivity endotherms go through to slow down metabolic rate and to survive cold and harsh winters. Animals that do not hibernate go on migration, which is a long distance movement of individuals on a seasonal basis.

o   Taxis and kinesis in animals

A taxi is a automatic movement towards or away from a stimulus. A animal will move closer or away from a stimulus . Kinesis is a simple nondirection change in activity or turning rate in response to a stimulus. This cause animal to run in a frenzy in response to something in its environment.

o   Chemotaxis in bacteria, sexual reproduction in fungi

Chemotaxis is a process in bacteria where they can detect food or poison and will move away or to the stimulus. For fungi to reproduce, pheromones are released as a social response to members of the same species to produces gametes.

o   Nocturnal and diurnal activity: circadian rhythms

Circadian rhythm is the biological clock that both plants and animals activity. Bats are nocturnal because they are inactive during the day and their circadian rhythm allows them to wake up for the night. In humans, the average person is designed to sleep during the night and be active during the day, people also can feel tired right after they wake up and they are in the middle of their circadian rhythm.

o   Shivering and sweating in humans

Your body respond to a change in your body temperature by either releasing sweat to reduces heat in your body, or shiver and your skin will get goose bumps to contain heat and produce heat to bring your body temp to its set point

2B Review

2.B.1

·      Discuss how cell membranes separate the internal environment of the cell from the external environment of the cell.

·      Cell membranes consist of proteins, lipids and Cholesterol and that regulate what can go in and what can go out.  The lipids and cholesterol do not allow things that are hydrophilic into the cell while proteins help move large substances that cannot pass the membrane, into the membrane.

·      Cells are selectively permeable. Discuss each point below and how it allows the cell to be selectively permeable.

o   Discuss the following structures and the role the play in the cell membrane: phospholipids, embedded proteins, cholesterol, glycoproteins and glycolipids

·      Phospholipids are a key component of the cell membrane that has both a hydrophobic and hydrophilic regions. The hydrophilic or “head” of the Phospholipid is faced towards water environments on the outside a d internal environments.  Temperature can affect phosphate movement.

·      There are three types of Embedded Proteins. There is internal membrane proteins that are connected into the phospholipid layer, trans membrane proteins that connected across the whole membrane and allow substances across the membrane, and Peripheral proteins that are bound to the membranes surface.  Membrane proteins help transport substances, signal other cells, and join the cell to the cytoskeleton and intercellular joining.

·      Cholesterol molecules increase firmness and integrity to keep the membrane regulated from becoming too fluid or firm.

·       Glycolipids: are located on the outside of the cell membrane and help Cells to recognize other cells.

·      Glycoproteins: are located on the outside of the cell membrane and assist in recognizing other cells, but are more common than a glycolipid.

·      Discuss the properties of a phospholipid (hydrophobic/phallic, polar/non, and fatty acids/phosphates.

·      A phospholipid is divided into two regions. The hydrophobic area that is phosphate and allows water to pass through it.  The hydrophilic area is lipid and does not allow water to pass through it.

·      Embedded proteins – how do they allow transport?

·      Embedded proteins allow transport by giving a passage for substances that cannot pass through the membrane. The transport protein allows certain molecules that are hydrophilic to pass through the tunnel.

·      Discuss which molecules can easily pass through the membrane and which can’t. Why?

·      Molecules that are hydrophilic can pass through the membrane easily because the phosphate that attract these certain type of molecules while other molecules cannot pass through because they are not attracted to those hydrophilic molecules and need the help of proteins to force there way in

·      Cell walls are a structural boundary that provides extra barrier for some organisms.

o   Discuss the cell wall of plant cells, prokaryotes and fungi, and what they are composed of.

o   Cell walls provided structure to a cell as well as a permeability barrier.  Plant cells are composed of cellulose and are on the outside of the cell membrane. Prokaryotic cell wars are composed of peptidoglycan. Fungal cell walls are made of chitin.

o    

2.B.2

·      Passive transport does not require the input of energy; the net movement of molecules is from high to low. Discuss the following factors relating to passive transport.

o   Discuss how primary transport allows for export of waste.

o   Passive transport allow for the export of waste by diffusing the molecules from high concentration to low concentration areas.

o   Discuss how membrane proteins play a role in facilitated diffusion of charged/polar molecules in the membrane. Use the examples of glucose and Na/K transport

·      Proteins play a role in facilitated diffusion by allowing charged molecules and polar molecules out and into the membrane. The example of the glucose transport is that electrochemical gradients help power a protein transport channel and allows for the channel to change its shape to move glucose molecules to the inside of the cell.

o   Discuss the following solutions and their effect on a cell. hypotonic, hypertonic, and isotonic.

o   A Hypotonic state is when there is more solute on the outside than inside the cell and can cause a cell to become shriveled and plasmolysis. 

o   A Hypertonic state is when there is more solute on the inside than the outside and can cause a cell to explode;

o   In Isotonic, the cell is at equilibrium and there is a same about of solute outside and inside

o   Discuss water potential and the formula for solving for it.

o   Water potential is defined as the potential energy of water transfer and the formula solves where the water will flow either in or out of a cell.

·     

o    TP is the pressure potential of the water while Solute potential is solution potential. The solute potential of regular water is 0.

·      Active transport requires free energy to move molecules against their concentration gradient from areas of low to high. Discuss the following factors relating to active transport:

o   Discuss where the free energy used in active transport comes from.

o   The free energy is found in the form of ATP

o   Discuss the membrane proteins needed for active transport.

o   The membrane proteins need for active transport is a protein pump

o   Explain how molecules are moved against their concentration gradient. Use the example of the Sodium Potassium Pump. 

o   Molecules are used  to move against the consentration gradient from a area of low concentration to a area of high concentration. In the Sodium Potassium pump, ATP powers the pump to change its shape to move the sodium and potassium against the gradient and move the Ions into or out of the cell.

o   Discuss the difference between endocytosis and exocytosis.

§  What happens in each?

§  In Endocytosis the cell membrane surrounds itself around a concentration of molecules and consumes it

§  In Exocytosis the membrane fuses molecules inside and force molecules out.

o   Discuss the difference between pinocytosis and phagocytosis.

o   Pinocytosis is when a cell consumes dissolved particles and is also know as cell drinking.

o   Phagocytosis is when a cell engulfs solid particles and material’s into the cell and is also known as “cell eating”

2.B.3

·      Discuss how internal membranes facilitated cell process by minimizing competing interactions by describing the activities of the lysosome.

·      Inside of a lysosome, the organelle contains thousands of enzymes that break down broken cell material and macromolecules. If there was no membrane around the lysosome then the cell would die from all the chemical reactions released from the enzymes.

·      Membranes and membrane bound organelles in eukaryotic cells processes. Discuss each of the following and how they compartmentalize: ER, mitochondria, chloroplast, Golgi, and nuclear envelope.

·      The ER is divided into two parts, the Rough ER and the Smooth ER. The rough ER is located near the nucleus and its job is to synthesize proteins from the ribosomes that are embedded on it. The smooth ER  detoxifies a cell, creates phospholipids and regulates metabolism

·      The mitochondria creates ATP for plant and animal cells  using the process of glycolysis, transition, the Krebs cycle and the electron transport chain  

·      The Chloroplast creates sugar for plant cells through the process of photosynthesis.

·      The Golgi apparatus ships proteins across the cell to where they need to be.

·      The nuclear envelope contains DNA, allows RNA to pass in and out of the nucleus and creates ribosomes

·      Discuss how prokaryotic cells function since they have no membrane bound organelles.

·      Enzymes inside of prokaryotes float around inside of the cell.