Biology 102 Final Set 3 Questions

Why is it critical for the body to get rid of or detoxify ammonia?

Ammonia interferes with ATP formation and production in mitochondria

What are the tradeoffs in mechanisms of ammonia excretion?

Ammonia- most aquatic animals; need access to lots of water; secrete from the body surface Urea- most terrestrial mammals and some aquatic animals; produced in the liver; energetically expensive (needs ATP) but conserves water. Uric Acid - insects, snails, reptiles, birds; relatively nontoxic; extremely ATP expensive but conserves the most water; waste is like a paste Energy Expense: Ammonia < Urea < Uric Acid Water Loss (and toxicity): Uric Acid < Urea < Ammonia

How do aquatic animals, insects, and terrestrial vertebrates acquire oxygen?

Aquatic animals use gills Insects use tracheal tubes that supply oxygen directly to body cells Terrestrial vertebrates use lungs

What is the function of the endocrine system?

Chemical signaling by hormones. Endocrine signaling maintains homeostasis, mediates responses to stimuli, regulates growth and development.

What are the barriers/filters to community assembly of species?

Dispersal (getting there) Adaptions to local conditions (having the traits that allow you to live where you got) Interactions with competitors, consumers, pathogens Priority effects (basically means when you get there is important; example: a goat swimming to the island with no plants)

What is the purpose of the Loop of Henle?

Reabsorption of water and salt from filtrate

Describe the process of antigen recognition and adaptive immune response

T or B cells bind to antigens via antigen receptors specific to part of one molecules of that pathogen

Be able to trace the path of an O2 molecule, from its entry to the nasal or mouth cavity, until it leaves the body as CO2?

(In order) Air passes through the nasal/mouth cavity, pharynx, larynx, trachea, bronchi, and the bronchioles to the alveoli, where gas exchange occurs

What drives fluid out and back into the capillaries?

Blood pressure drives fluid out of capillaries Osmotic pressure drives fluid into capillaries at the venule end

How does blood pressure change from the aorta, arteries, capillaries, venules, veins to the vena cava?

Blood pressure is highest in the arteries and veins, gets lower in the arterioles and venules, and is lowest in the capillaries. Ex: Arteries (high) -> arterioles (mid) -> capillaries (low) -> Venules (mid) -> veins (high)

How do erythrocytes (red blood cells) carry oxygen?

Erthrocytes contain hemoglobin, which is the iron-containing protein that transports oxygen

What are the homeostatic mechanisms of regulating arterial blood pressure?

Homeostatic mechanisms regulate arterial blood pressure by altering the diameter of arterioles (this occurs with negative feedback) Vasoconstriction is the contraction of smooth muscle in arteriole walls; it increases blood pressure (like putting a thumb over a hose opening) Vasodilation is the relaxation of smooth muscles in the arterioles; it causes blood pressure to fall

How do antibodies directly and indirectly effect a detected pathogen?

In neutralization, antibodies bind to viral surface proteins preventing infection of a host, causing a direct effect (Like a spider covering an insect with silk) Antibodies may also bind to toxins in body fluids and prevent them from entering body cells Opsonization, antibodies bind to antigens on bacteria, triggering phagocytosis; indirect (Basically like attaching a flag to a bacteria to make it noticeable so that macrophages can recognize them and eat them)

What is the site of vertebrate excretion and osmoregulation?

Kidneys

Why is the immune response different for previously encountered pathogens than novel pathogens?

The first exposure to a specific antigen represents the primary immune response During this time, selected B or T cells give rise to their effector forms Secondary immune response, memory cells facilitate a faster, more efficient response

How can a host cell infected by a pathogen alert the immune system?

The immune system recognizes bacteria and fungi structures on their cell walls Usually specific proteins, polysaccharides, or polymers

How is involuntary breathing controlled?

The involuntary breathing control centers are found in the medulla oblongata of the brain (basically our thermostat for breathing) The medullla oblongata regulates the rate and depth breathing in response to pH changes in the cerebrospinal fluid

How is fluid lost by capillaries returned to the circulatory system?

The lymphatic system returns fluid that leaks out from the capillary beds

If climate shifts have occurred in the Earth's past, what is different about the current shift?

The rate at which the climate is shifting is a lot greater than in Earth's past Ex: before, it took 1,000 years for Earth's climate to raise 4 degrees C. Now, it appears that it will only take 10 years to raise 4 degrees C.