Gaseous Exchange, Excretion, and Population Ecology Study Guide

Comprehensive practice questions covering gaseous exchange mechanisms, the human respiratory and urinary systems, homeostasis, and population ecology concepts.

How is cellular respiration defined in biological terms?

The breakdown of organic compounds like glucose/sugar in the mitochondria of cells into inorganic products ($CO_2$ and $H_2O$) with the release of cellular energy ($ATP$).

What is the mechanical process of inhalation and exhalation through which air moves in and out of the respiratory organs?

Breathing or ventilation.

What are the common requirements for an effective gaseous exchange surface across different organisms?

A large surface area, being thin and permeable, being moist, being well-ventilated, being protected, and having a transport system.

In terms of surface area to volume ratio, why do smaller organisms have an advantage for diffusion?

In general, the smaller the organism the larger the surface area to volume ratio, which optimizes the amount of surface relative to size for gas exchange.

How does the earthworm facilitate gas exchange and keep its respiratory surface effective?

It uses its thin skin as a respiratory surface and has mucous glands that keep the skin moist.

What structural adaptation protects the gills of a bony fish?

The operculum, which is a bony cover.

Which specific cells in the human nasal cavities are responsible for trapping dust and dirt?

Goblet cells, which produce mucus that works with cilia to sweep dirty particles out.

What is the function of the C-shaped cartilage rings found in the human trachea and bronchi?

They protect the trachea and keep the air passages open so they do not collapse during breathing.

Which structure prevents food particles from entering the trachea during swallowing?

The epiglottis, which is a cartilage structure on top of the larynx.

What occurs during the active phase of ventilation known as inhalation?

The diaphragm contracts and the thoracic cavity increases in volume, which decreases pressure so that air flows into the lungs.

Which part of the brain regulates the rate of breathing based on carbon dioxide levels in the blood?

The medulla oblongata.

By what mechanism is oxygen primarily transported in the human circulatory system?

It combines with the pigment haemoglobin in red blood cells (erythrocytes) to form oxyhaemoglobin.

What are the four main functions of the human urinary system?

Osmoregulation, excretion of nitrogenous waste, regulation of the pH of body fluids, and regulation of salt concentration in body fluids.

What is the structural relationship between the Bowman's capsule and the glomerulus?

The Bowman's capsule is a cup-shaped structure that encloses a dense capillary network called the glomerulus; together they form the Malpighian body.

What are podocytes and where are they located?

They are special cells with finger-like extensions and slits located in the inner lining of the Bowman’s capsule that wrap around the capillaries of the glomerulus.

What are the four processes involved in the formation of urine?

1. glomerular filtration or ultrafiltration, 2. tubular re-absorption, 3. tubular secretion, and 4. excretion.

Which hormone produced by the adrenal cortex promotes the reabsorption of sodium ions ($Na^+$) in the kidneys?

Aldosterone.

How does Antidiuretic Hormone (ADH) affect the kidneys when the body is dehydrated?

It increases the permeability of the cells in the walls of the distal convoluted tubule and the collecting duct, allowing more water to be re-absorbed into the blood.

What is the formula used in the mark-recapture technique to estimate population size?

$P = \frac{F \times S}{M}$ where $F$ is the number caught in the first sample, S$ is the number caught in the second sample, and M$$ is the number marked in the second sample.

What are the five phases of the logistic (S-shaped) growth curve?

1. Lag phase, 2. Exponential or accelerating growth phase, 3. Decelerating growth phase, 4. Equilibrium/stationary phase, and 5. Death/extinction phase.

What is the difference between interspecific and intraspecific competition?

Interspecific competition occurs between different species, while intraspecific competition occurs between members of the same species.

How is resource partitioning defined in the context of ecosystem niches?

It is a specialization where species use resources slightly differently or occupy different ecological niches to limit interspecific competition and coexist.

What is the symbiotic relationship where one organism benefits and the other is unaffected?

Commensalism.

What instrument is used to measure the volume of air entering and leaving the lungs?

A spirometer.