Bio 111 Exam 3 Rochester

Front 1

What is the echinoderm endoskeleton made of?

Back 1

Calcium Carbonate

Front 2

What is the diagnostic trait of vertebrates?

Back 2

vertebrae and a cranium

Front 3

Why are the pharyngeal jaws found in many ray-finned fishes important?

Back 3

they help process food

Front 4

Which of the following lineages make up the living Amniota?

Back 4

reptiles and mammals

Front 5

What is the relationship between the dorsal hollow nerve cord and the spinal cord?

Back 5

The spinal cord is a type of dorsal hollow nerve cord

Front 6

Most species of hominins are known only from Africa. Which species have been found in other parts of the world as well?

Back 6

H. erectus, H. neanderthalensis, and H. floresiensis

Front 7

Explain how the water vascular system of echinoderms functions as a type of hydrostatic skeleton

Back 7

It is an enclosed, fluid-filled structure surrounded by muscle. Muscular contraction forces water into the tube feet, resulting in extension of the podia.

Front 8

Explain why each of the four key synapomorphies that distinguish chorates is important in feeding or movement. Why is it possible to say that an animal is "invertebrate chordate?

Back 8

Pharyngeal gill slits function in suspension feeding. The notochord furnishes a simple endoskeleton that stiffens the body; electrial signals that coordinate movement are carried by the dorsal hollow nerve cord to the muscles in the tail, which beats back and forth to make swimming possible.

Front 9

The cells that make up jaws and gill arches are derived from the same population of embryonic cells. Why does this observation support the hypothesis that jaws evolved from gill arches in fish?

Back 9

If jaws are derived forms of gill arches, then the same genes and the same cells should be involved in the development of the jaw and the gill arches.

Front 10

Describe genetic evidence that supports the hypothesis that the tetra limb evolved from the fins of lobe-finned fishes.

Back 10

Homologous genes are involved in the formation of the fins of ray-finned fish and the limbs of tetrapods. This observation supports a prediction of the fins-to-limbs hypothesis.

Front 11

The text that claims that "homo sapiens is the sole survivor of an adaptive radiation that took place over the past 7 million years" Do you agree with this statement?

Back 11

The hominins fulfill the criteria for an adaptive radiation: over a short time interval, many species that occupy an array of foods and habitats evolved. Chages in tooth and jaw structure, tool use, and body size suggest that different hominin species exploited different types of food.

Front 12

Explain how the evolution of the placenta and lactation in mammals improved the probability that thier offsping would survive compared to species without parental care.

Back 12

Increased parental care allows offspring to be better developed, and thus have increases chances of survival, before they have to live on there own.

Front 13

There is some evidence that pharyngeal gill slits occur in certain species of echinoderms that appear early in the fossil record. Explain the significance of this observation.

Back 13

If confirmed, it means that pharyngeal gill slits were present in the earliest echinoderms and lost later.

Front 14

When feathers first evolved, did they function in flight? Explain your logic

Back 14

No - the first feathers may have functioned in display or as insulation.

Front 15

The mycelial growth habit leads to a body with a high surface-area-to-volume ratio. Why is this important?

Back 15

Mycelia have a large surface area for absorption

Front 16

What is plasmogamy?

Back 16

fusion of the cytoplasm from different individuals, without nuclear fusion

Front 17

The Greek root ecto means "outer". Why are ectomycorrhizal fungi, or EMF, apty named?

Back 17

Their hyphae form dense mats that envelop roots but do not penetrate the walls of cells inside the root.

Front 18

The hyphae of AMF form bushy of ballon-like structures after making contact with the plasma membrane of a root cell. Why?

Back 18

They increase the surface area available for the transfer of nutrients

Front 19

What does it mean to say that a hypha is dikaryotic or heterokaryotic?

Back 19

Two or more independent nuclei, derived from different individuals, are present.

Front 20

Very few organisms besides fungi have a heterokaryotic stage in their life cycle. Which of the following is another unusual aspect of fungal life cycle?

Back 20

Most varieties undergo sexual reproduction without producing eggs or sperm.

Front 21

Explain why fungi that degrade dead plant materials are important to the global carbon cycle. Do you accept the text's statement that, without these fungi, "Terrestrial environments would be radically different than they are today and probably much less productive? Why or why not?

Back 21

Along with a few bacteria, fungi are the only organisms that can digest wood completely. If the wood is not digested, carbon remains trapped in wood. Without fungi, CO2 would be tied up and unavalialbe for photosynthesis, and the presence of undecayed organic matter would reduce the space available for plants to grow.

Front 22

Lignin and cellulose provide rigidity to the cell walls of plants. But in most fungi, chitin performs this role. Why is it logical that most fungi don't have lignin or cellulose in their cell walls?

Back 22

Fungi produce enzymes that degrade cellulose and lignin

Front 23

Biologists claim that EMF and AMF species are better than plants at acquiring nutrients because they have a higher surface area and because they are more effective at acquiring phosphorus (P) and/or nitrogen (N). Compare and contrast the surface area of mutualistic fungi and plant roots. Explain why fungi are particulary effefienct at acquiring P and N, compared to plants.

Back 23

Plant roots have much smaller surface area than EMF or AMF. Hyphae are much smaller than the smallest portions of plant roots so can penetrate dead material more efficiently. Extracellular digestion - which plant roots cannot do - allows fungi to break large molecules into small compounds that can be absorbed.

Front 24

List 3 key macromolecules found in plants that contain phosporus. Explain why plant growth might be limited by access to P.

Back 24

DNA, RNA, and ATP all contain phosphorus. Without adequate amounts of phosphorus, plants cannot grow by synthesizing more DNA, RNA and ATP.

Front 25

Compare and contrast the way that the fungi degrade lignin with the way that they digest cellulose

Back 25

Both compounds are processed via extracellular digestion. Different enzymes are involved, however. the degradation of lignin is uncontrolled and does not yield useful products; digestion of cellulose is controlled and produces useful glucose molecules.

Front 26

How is it possible for thousands of mating types to exist in a single species of fungus, instead of just two sexes like other eukaryotes?

Back 26

Most fungi do not make gametes. Instead the products of specific alleles identify mating types -- probably to encourage fusion between hypae that are dissimilar genetically, resulting in the production of genetically diverse offspring. It is possible for thousands of different mating-type alleles to exist in a population.