AECL 365: Vertebrate Biology: Exam 1: Iowa State University: Fall 2018: Dr. Dean Adams

What is a Scientific Hypothesis?

A proposed explanation for natural phenomena that can be falsified and make predictions.

True or False: Creativity plays no role in the scientific process.

False

More than half of all living vertebrates are ________

Fishes

True or False. Taxonomy is the scientific discipline of providing names for groups of organisms and placing them in a hierarchical classification system.

True

A necessary component of evolution by natural selection is that _____.

There is trait variation among individuals.

The Observation that endotherms tend to be larger in colder climates is called _____.

Bergmann's rule

What geologic period is known as the "Age of Fishes"?

Devonian

The class Chondrichthyes contains over 1,200 species of cartilaginous fish, whose common names include_____.

sharks, chimera, skates, and rays.

An extinct class of fish characterized by heterocercal tails and bony armor plating are the_____.

Placodermi

_____ are thought to be a part of the evolutionary lineage leading to terrestrial vertebrates.

Osteolepiform

Which of the following is not an order of extant Lissamphibia?

Gymnophiona.

True or False: The order Gymnophiona contains over 200 amphibian species that are legless and tailless.

True

Which part of the amniote egg is responsible for storing waste?

Allantois

An example of an extant anapsid is a:_____.

Turtle.

Name an example of an extant lepidosaur.

Tuatara.

In 1862 a fossil of _____ was discovered in a quarry in Germany that contained both reptile and bird-like characteristics. It is considered the first true bird in the fossil record.

Archaeopteryx

There are approximately _____ species of birds known.

10,000

The _____ is a lineage of flightless birds found with a Gondwanan distribution, and phylogenetically are basal to other bird lineages.

Struthioniformes

Mammals experienced an adaptive radiation in the Cenozoic. What is one probable reason for this adaptive radiation.

The demise of dinosaurs and many other reptiles.

True or False: In mammals, the quadrate and the articular bones have been modified from their ancestral condition, and are now found as the incus and stapes of the mammalian middle ear.

False

True or False: The evolution from a sprawling posture in reptiles to having limbs located under the body in mammals allowed for more rapid and more efficient locomotion.

True

_____ bones form with no cartilaginous precursor.

Dermal

The axial skeleton is comprised of all the following except _____.

Choices: Vertebrae, Phalanges, Cranium, Sternum. ANSWER: Phalanges.

List the major vertebrate lineages in terms of the number of bones in their skull, most-to-least.

Fish, amphibians, reptiles, mammals.

_____ muscle contains spindle-shaped fibers, is associated with many internal organs, and is typically under involuntary control.

Smooth

Muscles are made up of a series of nested unites. List them from largest to smallest.

Fiber, fascicle, myofibril, myofiliment

The muscles of a fish display little specialization and are arranged primarily in thin, vertical segmental bands called _____.

Myomeres.

The ______ are tiny blood vessels where the exchange of oxygen, nutrients, and waste takes place between the circulatory system and the tissue cells.

Capillaries

Which of the following vertebrate lineages have four chambered heart.

Choices: Aves, Crocodilia, Mammalia, All have a four-chambered heart.
ANSWER: All have a four-chambered heart.

The Bohr effect explains why _____.

Hemoglobin unloads its oxygen when it encounters low pH.

In fish, the _____ are thin projections of the gills which contain the capillary networks that are the site of gas exchange.

Lamellae

In diving mammals, which of the following is NOT an adaptation for extending time beneath the water's surface without breathing?

Options: They have much larger quantities of body mass, they store large amounts of oxygen in their lungs, they derive ATP from fermentation rather than respiration, The myoglobin in their muscles is capable of story oxygen.
ANSWER: They store large amounts of Oxygen in their lungs.

Evolution frequently proceeds by the process of natural selection. What are the four conditions/components that will result in evolution by natural selection within a population?

1. More individuals are born each generation than can survive and reproduce.
2. There is trait variation among individuals
3. At least some of this trait variation is heritable
4. Trait differences are tied to fitness.

Name the three main types of skull fenestration and briefly define what they are and which extant vertebrate groups exhibit them.

1. Anapsid - no fenestrations - testudines.
2. Synapsid - one fenestration - mammalians
3. Diapsid - two fenestrations - many reptiles/birds.

Muscle fibers contract in an all-or-none fashion. Therefore, how is continuous movement of a muscle achieved?

Not all fibers are activated. The more fibers that are activated, the more movement.

What are the three main ways of enhancing gas exchange? Discuss how of these are each accomplished in fish and tetrapods by comparing aspects of gills and lungs.

1. Increased surface area - many alveoli in lungs/lamellae in gills increase surface area to volume ratio.
2. High gas gradient - keeping different concentrations of CO2 and O2 between membranes.
3. Thin/moist membrane for exchange. Keep gills/alveoli/skin(cutaneous respiration only) moist.

Briefly Compare the structure of the heart (chambers) as found in a fish, amphibian, and mammal, and describe the circulation path the blood follows.

Fish: 2 chambers and have one way out and one way into their heart for blood and flows through the kills for gas exchange.
Amphibian: 3 chambered heart (4 chamber in crocodilians). Atrium (two present) pumps blood away from heart via arteries, ventricle (one present) receives deoxygenated blood via veins. Hemiseptum present (unclosable gap) between what would be the left and right ventricle in mammalian heart which is why there is only one ventricle.