FINAL BIO EXAM 112 - Lab 17 The Deuterostomes

What does the archenteron develop into in the adult?

The archenteron develops into the mouth in the adult.

What does the blastopore become in the adult?

The blastopore becomes the anus in the adult.

You can tell male from female by the appearance of the gonads. How do ovaries look different from testes?

Appearance-wise, the testes are whiter and smaller compared to the ovaries. Female gonads, when opened, have numerous amounts of ovaries inside whereas the testes have nothing inside.

The bipinnaria larva displays what type of body symmetry?

Bilateral symmetry

What is the blastocoel?

Blastocoels are fluid (segmentation cavity) in the blastomeres.

What are blastomeres?

Blastomeres are cells formed by cleavage of a fertilized ovum.

The esophagus is the opening into what body system?

It is an opening to the digestive system.

The glottis is the opening into what body system?

It is an opening to the respiratory system.

How and where are perch eggs fertilized?

Perch eggs are fertilized through the process of external fertilization, meaning that the perch eggs are fertilized outside the body and in the water environment.

What is the function of the spleen?

Spleen filters through our red blood cells and helps with immunity.

Tetrapods, such as amphibians, reptiles, and mammals, are terrestrial relatives of the bony fish. Which of your appendages are homologous to the pectoral fins of a perch? Hint: think about where your pectoral muscles are.

Tetrapod forelimbs are homologous to the pectoral fins of a perch.

Which of your appendages is homologous to the pelvic fins of a perch? Hint - Think about where your pelvis is.

Tetrapod hindlimbs are homologous to the pelvic fins of a perch.

How is the attachment of a frog's tongue different from ours?

The attachment of a frog's tongue is different from ours is that it is attached to the front of their mouths.

What is the benefit of the countershading (dark on top, light on bottom) seen in frog coloration?

The benefit of countershading seen in frog coloration is that it protects them from any predators.

When fish are swimming what part of their anatomy provides speed (forward motion)?

The caudal fin provides speed in a forward motion

Why might a chytrid skin infection be so deadly to frogs?

The chytrid skin infections can be deadly to frogs because it causes the skin to become thicker, making it harder for gas exchange to occur in frogs

The cloaca is a common opening for which three body systems?

The cloaca is a common opening for the digestive, reproductive, and urinary systems.

The cloaca is an opening into which body system(s)?

The cloaca is an opening into the reproductive, digestive, and urogenital systems.

What conditions are needed for efficient gas exchange?

The conditions that are needed for efficient gas exchange is that their skin must be moist

Speculate on the function of the canaliculi. (Hint: Think about the structure of the matrix and the structures found in each Haversian canal.)

The function of the canaliculi is that they link together through these small channels and the lacunae and they also navigate the nutrients to the osteocytes and expel any waste products.

The figure above shows an Amphioxus (Lancelet) whole mount. Give the labels for the following structures.

the dorsal fin myomeres oral tentacles pharynx intestine

List two anatomical features of the frog that make them good jumpers

1. Leg muscles 2. Skeletal bones in the legs

In the perch, eggs exit through which opening?

Eggs exit through the cloaca opening.

What are fish scales made of?

Fish scales are made of very thinned down bone.

Frogs may have a large tympanum, but the range of pitches that a frog can hear is quite limited. What do you think frog ears are adapted to hear?

Frog ears are adapted to hear mating calls.

Where do frogs do most of their gas exchange?

Frogs get the most of their gas exchange through their thin skin.

Which do you think would be more efficient at carrying oxygen, human or frog red blood cells? What can you infer about the metabolic needs of amphibians versus humans based on these observations?

I think that human red blood cells would be efficient in carrying oxygen than frog red blood cells due to the nucleus not being present. Amphibians do not require much energy for metabolic processes in comparison to humans. Humans require more energy because they move around more and have to constantly regulate internal temperatures.

Look at the slide of frog blood again. What do you notice that is present in frog red blood cells that is absent in human red blood cells?

In frog red blood cells, there is a nucleus present but in human red blood cells there is no nucleus present.

How can you differentiate between "early" and "late" blastulas?

Late blastulas are larger in size compared to early blastulas.

Why do male perch need to make a lot of sperm?

Male perch need to make a lot of sperm in order to increase their reproductive success and allow some sperm to reach the egg.

The striations in skeletal muscle are the result of the regular arrangement of what two proteins that function in contraction?

Myosin and actin function in contractions of the muscle therefore there are striations in the skeletal muscle.

What is the function of the epithelial layer that lines the lumen of the intestine? How is this function reflected in its structure?

The function of the epithelial layer that lines the lumen of the intestine is that they form barriers and change surfaces to maintain what passes through them. Since the epithelial layer is thick, it provides protection, and the thinner layers provide efficient exchange surfaces.

What is the function of the lateral line?

The function of the lateral line is detecting pressure changes and vibratory currents in the water.

This is a longitudinal section through cardiac muscle (above). Here you can see the nuclei as well as dark striations, called intercalated disks where two cardiac muscle cells meet (see arrows). These connections between cells contain many gap junctions. What do these gap junctions allow the cardiac muscle cells to do?

The gap functions allow cardiac muscle cells to initiate rapid communication between other cardiac muscle cells.

. The image above is a cross section through a frog intestine. On the right is an image at higher magnification looking at the muscles in the wall of the intestine. Here you can see two layers of smooth muscle: the inner layer is circular, and the outer layer runs longitudinally. What is the function of these muscles in the small intestine?

The inner circular layer and the outer longitudinal layer functions in contraction in the small intestine and both participate in the peristaltic wave where the circular muscle relaxes while the longitudinal muscle contracts.

Which stage of the tunicate life cycle displays all four chordate characteristics?

The larval stage of the tunicate life cycle displays are four-chordate characteristics.

What function do the nostrils serve in a fish?

The nostrils are sensitive to dissolved chemicals in the water, and it allows them to smell chemicals in the water.

The operculum covers the gills. It protects the gills, but what else does it do?

The operculum is used for breathing and pulls water into the gills.

Starting at the atrium, trace the path of blood through the fish body.

The path of blood through the fish body is single circuit, so it goes from the atrium to the ventricle, to the gills and then to the body tissues.

What part(s) provide maneuverability?

The pelvic and the pectoral fin provides maneuverability.

What is the primary function of frog teeth?

The primary function of frog teeth is to hold down their food so that they can swallow.

How does the size of a fish heart compare to the heart of invertebrates?

The size of a fish heart compares to the heart of the invertebrates is that the blood flows in a single circuit and it is two-chambered heart. Therefore, it is more complex and larger.

What has the swim bladder evolved into in other animals?

The swim bladder has evolved into the lungs in other animals.

Notice the five paired rows of perforations (pores) in the urchin shell in the figure above. What purpose do these small holes serve? In other words, what would you find coming out of them?

The tube feet come out of these holes and they function in locomotion.

What is the function of the tympanum?

The tympanum functions as the ear of the frog

Each ampulla is attached to a tube foot that emerges from the other side of the sea star. On a living sea star, each tube foot is small and seems fragile. How can you explain their ability to hold a sea star tightly onto a rock even in strong waves?

Their ability to hold a sea star tightly onto a rock is due to the suction of the tube feet (& there is a lot of tube feet)

Ray-finned fishes are the largest group of vertebrates. How many different species are there?

There are more than 20,000 different species in the ray-finned fishes.

What might be the advantage of this arrangement?

This flexible arrangement allows frogs to capture its prey like flies and to bring their prey to their mouth