Biology Chapter 19

Front 1

A ______________ is defined as a period of unconsciousness that lasts over an hour, during which the patient’s eyes are closed.

Back 1

coma

Front 2

One reason why humans and other animals have been successful is because of their ________________ body plan.

Back 2

Bilateral

Front 3

The Swedish botanist Carolus Linnaeus invented the classification system that is used by modern biologists, which relies on __________________ traits to distinguish among species.

Back 3

morphological

Front 4

These proteins which act like cellular “glue” to hold cells together is called _________________.

Back 4

collagen

Front 5

This protein was first used by the group of animals known scientifically as __________________.

Back 5

Porifera

Front 6

Although sponges have no muscle, no neurons, and no brain, they do have specialized cells for eating and moving water. This specialization occurred first in this group and is known as ___________________.

Back 6

cell differentiation

Front 7

Muscle tissue is the same in all animals, from the jelly fish to humans. The two types of proteins which enable muscles to contract are _______________ and ______________.

Back 7

actin, myosin

Front 8

To coordinate the motion of muscles, the cnidarians have a simple network of ________________ that allow the muscle fibers to communicate using a combination of electrical impulses and chemical signals.

Back 8

nerve cells

Front 9

Most marine flatworms produce both eggs and sperm, a condition known as __________.

Back 9

(hermaphroditism)

Front 10

What happens if the brain is not supplied with blood?

Back 10

The delivery of oxygen to the brain is dependent on an adequate blood supply. When this supply is stopped the cells begin to die. Cells within the cerebral cortex are affected first. Damage to the cerebral cortex leads to loss of memory and cognitive behavior. If the blood supply cut off is severe enough the brain stem is affected causing loss of basic functions.

Front 11

How does a bilateral body plan help humans?

Back 11

The human body can be divided into 2 halves producing mirror images of each other. All sensory organs are paired and arranged symmetrically. This arrangement allows for the development of stereoscopic sensing which helps in determining the direction of stimuli. By having paired appendages we can move with greater swiftness and stability.

Front 12

Explain what is involved in a muscle contraction.

Back 12

Muscle fibers contain individual contractile units known as sarcomeres. Each sarcomere contains thick (myosin) and thin (actin) filaments. The thick myosin filaments have protrusions like oars that connect with the thin filaments. When stimulated, the oars utilize the energy from ATP and pull the thin filaments toward it, similar to rowing a boat. A large muscle contracts only when millions of sarcomeres work together.

Front 13

Describe the radial body plan. Describe the bilateral plan and what are its advantages? For each body plan, give the first organism that first evolved this body plan. Once the bilateral body plan evolved, what advantage did it have for feeding?

Back 13

Radially body plan has regular repeating pattern around a central axis (like a wagon wheel), or completely symmetrical (like a dinner plate) with no left or right orientation but possessing top and bottom orientation.

The bilateral body plan can be divided into two halves, each being a mirror image of the other.

All sensory organs are paired and are arranged symmetrically with this arrangement animals were able to develop stereoscopic sensing that allows the direction of stimuli to be determined. Having paired appendages means that animals can move with a greater swiftness and stability. The paired sensory organs are located adjacent to the brain, the control center. This placement allows for the information that is obtained from the sensory organs to be rapidly communicated to the brain.

The Cnidarians were the first animal to have a radial body plan, whereas the flat worm were the first to have a bilateral body plan.

The bilateral body plan allowed for the first hunters to evolve, which could seek out prey.