Bio 1201 exam 1

Match each microbiome with its host. 1. brown bears 2. tunicates 3. tree 4. termites

1. Bacteroidetes help break down fat in winter. 2. Microbiome produces sterols and defensive molecules. 3. Ectomycorrhizae supply water and minerals. 4. Gut bacteria help digest plant matter.

Members of the Nostoc genus have large numbers of thylakoid membranes, and many have gas vesicles. What statement is also most likely true about Nostoc?

They are photoautotrophs.

Which statements are true regarding microbiomes? (Check all that apply.)

They can help facilitate human digestion. Horizontal gene transfer often occurs among members. They can be indicators of human health.

What is a characteristic of most animals?

They have Hox genes.

Which of the following statements does NOT describe a function of the cell walls of bacteria?

They prevent horizontal gene transfer.

What is the primary characteristic that groups phyla within the Ecdysozoa?

They shed their exoskeletons.

Which of the following statements DOES NOT characterize decomposers?

They synthesize organic molecules.

Place the correct terms into the sentences about protist movement.

Tiny hairlike structures called cilia are characteristic of certain protists. Certain protists use a long whip-like structures called flagella to swim. Amoeboid movement is carried out using structures called pseudopodia.

Which of the following is NOT a way that bacteria benefit humans?

Transferring nutrients across intestinal membranes

The graph above shows the reproductive capacity of a single bacterial cell over the course of only twelve cell divisions. Based on this information, how many more cells were there after the 11th division compared to the number of cells following the 10th division?

double the number

Germ layers are

embryonic layers with different developmental potentials.

An individual human can be thought of as a ________, consisting of a host and a variety of microbes. DNA from saliva or fecal samples, for example, would reveal the DNA genomes of both the host and its symbiotic microbes, known together as the ________.

holobiont, hologenome

The process by which genetic material is exchanged between different species, such as an endosymbiont and its host, is:

horizontal gene transfer.

Knowledge of a pathogen's genome is useful because:

it allows the development of drugs that target metabolic pathways unique to the pathogen.

Eutherian mammals are uniquely defined by

longer gestation periods because of more highly developed placentas.

A horseshoe-shaped crown of tentacles used by many invertebrates for feeding is called a

lophophore.

Plasmodium falciparum is a protistan parasite, borne by mosquitoes, that constitutes a serious health problem for humans. The disease it causes is:

malaria.

Ecdysis is

molting of the exoskeleton.

Place the correct terms into the sentences about fungal relationships with other organisms.

A saprobe is a fungus that decomposes organic matter. Plant diseases are caused by pathogenic fungi. Certain fungi form mycorrhizae with plant roots in a beneficial association. Fungi called endophytes live compatibly within the leaves of plants. A lichen is a cooperative association between fungi and certain types of algae.

Many insects make larvae that are very different from the adults. What do you think are advantages of this system? (Check all that apply)

Adults and offspring would not compete for food sources. Adults and offspring would not be vulnerable to the same predators. Adults and offspring would not compete for habitats.

What evolutionary trait do frogs and other amphibians lack (but reptiles have) that continues their association with water?

Amniotic egg

A mother ship arrives from Planet Lichen to take all lichens on Earth back to their home planet. What would be the consequences of the removal of lichens from Earth? Check all that apply.

An emergency food source would not longer be available to organisms such as reindeer and even humans. Nitrogen fixation will decrease.

The primates share several characteristics, which distinguish them from all other mammalian orders. Check all of the unique features that one would use to classify members into this order. (Check all that apply)

An opposable thumb A large and well-developed brain Binocular vision

Before the development of molecular techniques, scientists classified animals based on shared morphological and embryological characters. Complete the sentences discussing the basis for traditional animal classification.

Animals collectively known as the Eumetazoa possess specialized tissues. The Eumetazoa are divided into the Radiata and the Bilateria; this division is based upon each group's unique symmetry. The Bilateria are, in turn, divided into three major classifications based upon the structure of the body cavity. This feature is important because it allows for organs to be cushioned by fluid that is relatively incompressible. Lastly, animals can be classified by the way their zygotes subsequently divide to form a multicellular individual; the embryological pathway can proceed by either radial or spiral cleavage.

Consider a bean plant growing in a "Three Sisters" garden. The bean's stem twines up on corn plants, and its roots are shaded by squash plant leaves. The bean's roots have nodules with nitrogen-fixing bacteria, and a close association with mycorrhizal fungi in the soil. The bean flowers are pollinated by bees, and the seeds may be dispersed by rodents. Which species would be considered to comprise the bean's holobiont? (Check all that apply)

Bean, Nitrogen-fixing bacteria, mycorrhizal fungi

You have the pleasure of observing wood frog tadpoles in a pond on campus. You see them make the transition from gilled larvae into adults with lungs. In order to make this amazing transformation from an entirely aquatic life to one that includes time on land, your tadpoles will face a series of obstacles, not unlike those that the first vertebrate inhabitants of land faced. Complete the following sentences to correctly examine those changes.

Because of their large body size, ancestral amphibians likely faced challenges supporting themselves out of the aquatic environment. Although there was far more oxygen available to gills in air than in water, the delicate structure of gills couldn't be supported in the terrestrial environment. The costs of locomotion on land and greater oxygen demand from enlarged muscles led to modifications of the heart and circulatory system. These early amphibians could not venture too far away from water because egg deposition was restricted to moist environments.

Why would a researcher choose to engineer a synthetic gut microbiome, versus simply performing a fecal transplant?

Better control over the levels of helpful and harmful species.

What might be a desired agricultural outcome of engineering a microbiome? Choose all that apply.

Better nourished livestock Crops that are more resistant to fungal pathogens Higher crop yields More resilient honeybee colonies

What process is responsible for bacterial reproduction?

Binary fission

Which fish were thought to be extinct, but were actually found in living populations?

Coelacanth

You are presented with a newly discovered invertebrate species. As you observe individuals of the new species in your lab, you note that the animals shed their skin. Which designation might this lead you to consider?

Ecdysozoa

Which statement most accurately describes the evolutionary relationships among the three domains?

Eukarya and Archaea diverged from a common ancestor more recently than they diverged from their common ancestor with Bacteria.

What unique trait do bats have that no other mammal has?

Flight

The vertebrate chordates have several features that set them apart from their invertebrate chordate relatives and have allowed them to move into novel environments on land and in the air. Complete the following sentences discussing the features of the vertebrates.

For the majority of vertebrates, the notochord is replaced by the vertebral column during embryonic development. The cranium and vertebral column are parts of the endoskeleton. This structure is composed of either bone or cartilage. Vertebrates possess a great diversity of internal organs. These include a heart with at least two chambers.

While on a nature walk, a student finds fungal fruiting bodies growing along the trail. He decides to bring them home so he can consume them with dinner. Why is this unwise?

Fungal fruiting bodies may be toxic—only an expert can identify these toxic types.

Place the characteristic into the appropriate category of cell wall type.

Gram-Positive: acidic polysaccharides on surface, appears purple when stained, thick peptidoglycan layer, sensitive to penicillin Gram-negative: outer lipopolysaccharide layer, appears pink when stained, thin peptidoglycan layer, resists penicillin

Plants share a most recent common ancestor with what group of protists?

Green algae

What trend might result in delayed establishment of the gut microbiome by human infants?

High rates of birth by Cesarean section

Dragonflies, like all arthropods, have an exoskeleton. What are the possible advantages to this characteristic that has helped groups like the insects become so successful? (Check all that apply)

Inhibits water loss Muscle attachment Protection

Which of the following is NOT true of horizontal gene transfer?

It occurs when genes are transferred from parent to progeny.

Reptiles are better adapted to life on land than are amphibians. Which external characteristic would a reptile have to lose to make it roughly externally equivalent to an amphibian in terms of ability to tolerate dry land?

Keratin-rich scales

What are the characteristics of sharks? (Check all that apply)

Large oil-filled liver Powerful sense of smell Colorblind Able to sense movements in surrounding water

What is the source of energy for the synthesis of organic molecules in a photoautotroph?

Light

Which of the following traits are possessed by amphibians but are not present in fish?

Limbs

Place the item into the correct sentence about the industrial applications of bacteria.

Milk producers use bacteria to produce lactic acid for curdling milk. Bacteria are used by the pharmaceutical industries to produce antibiotics. In agriculture, bt toxin from bacteria is used to control plant pests. DNA amplification in the laboratory is facilitated by the bacterial production of DNA polymerase.

Your interest in the evolution of early animals from non-animal ancestors means that you have done a lot of reading on choanoflagellates. When asked what the evidence is by your roommate which of the following would you state to explain that choanoflagellates are thought to be the closest living relatives to animals? (Check all that apply)

Molecular comparisons between choanoflagellates and simple animals are similar. They are similar to the cells of simple animals.

All animal species have general characteristics in common. Check all of the characteristics that would apply to members of the animal kingdom. (Check all that apply)

Most animals have a muscle system that allows for active movement. Most animals undergo sexual reproduction where a small motile sperm cell unites with a larger egg to produce a zygote. All animals are heterotrophs.

In your zoology class, you are given a model of a lobe-finned fish to study. You immediately note that this fish is distinctly different from a ray-finned fish. Noting these differences and based on what you know about the differences between these two types of fish, what do you expect a lobe-finned fish might be able to do that a ray finned fish could not? (Check all that apply)

Move across land using fins Breathe air outside of water Possess lungs

What is the function of the molluscan foot?

Movement

A cosmetics company is researching a new type of sunscreen that would use both mineral protection (i.e. zinc oxide) and a secret ingredient harvested from bacteria. What is most likely to be the secret ingredient?

Mucilage

Which of the following is NOT a function of mucilage in bacteria?

Nitrogen fixation

Recent years have seen an increase in products with antimicrobial properties. The most common human pathogens are microbes—yet some people argue that these products may be counterproductive and actually harm human health. What correct statements would support this position? (Check all that apply)

Normal human skin has hundreds of bacterial genera, many of which provide beneficial functions. Antimicrobial chemicals may harm beneficial bacteria as well as pathogens. The proportion of specific bacteria types in the gut microbiome has been associated with growth rates in children.

Place the item into the correct sentence about prokaryotic metabolism.

Organisms called photoheterotrophs use light as an energy source but cannot synthesize their own organic compounds. A prokaryotic metabolism that uses inorganic compounds as an energy source to synthesize organic molecules is found in chemolithoautotrophs. Organisms called photoautotrophs use light for energy and CO₂ as a carbon source. A prokaryotic metabolism that uses organic compounds for energy and as a carbon source is found in chemoheterotrophs.

Which of these could be characterized as a microbiome? (Check all that apply)

Plaque scraped off a person's teeth The collection of archaea and bacteria species living in a deep-sea hydrothermal vent A broad collection of bacteria collected from an animal's intestinal tract

A newborn infant was treated with antibiotics due to an infection. The population of Bifidobacterium in her gut was greatly diminished. What would you predict could result from this change? (Check all that apply)

Poor digestion of milk. Slower growth rate.

What statements correctly describe this photograph? Choose all that apply.

Red color is a substance released by microbes Part of the cryosphere

In the Gulf of Mexico, red tides caused by the dinoflagellate Karenia brevis cause massive fish kills as well as respiratory problems in humans. As an environmental scientist, what would you suggest concerned citizens do to help prevent these red tides?

Reduce fertilizer use on lawns and gardens

Why are choanoflagellates considered to be the ancestor of animals?

Similarities in cell structure

One of the students in your study group is struggling with the idea that mammals and vertebrates are separate designations. To illustrate the two terms, you describe an animal that has the expected mammalian characteristics. What should you include in your description of this animal that would make it clear that the animal is specifically a mammal and not just a vertebrate? (Check all that apply)

Specialized teeth Enlarged skull Hair Three middle ear bones

Which of the following diseases is NOT caused by endospore-forming bacteria?

Strep throat

Unlike non-spore forming bacteria, bacteria that form spores are capable of what?

Survival under adverse environmental conditions

Which statement best explains nitrogen fixation carried out by prokaryotes?

The conversion of atmospheric nitrogen into a reduced form of nitrogen that can be used to produce amino acids

Place the item into the correct sentence about prokaryote classification.

The domain Eukarya shares a most recent common ancestor with the domain Archaea. Archaea and Bacteria are often grouped together because they have a prokaryotic structure, even though this group is not monophyletic. The maintenance of plastids within eukaryotic cells was facilitated by horizontal gene transfer following endosymbiosis. One characteristic shared by Bacteria and Eukarya is the presence of ester bonds in their membrane lipids. Cyanobacteria differ from other prokaryotes because they carry out photosynthesis and generate oxygen.

What is the fate of the embryonic germ layers?

The endoderm forms the gut, the ectoderm forms the epidermis and parts of the nervous system, and the mesoderm forms muscles and most internal organs.

Examine the significance of the evolution of the amniotic egg by completing the following sentences.

The evolution of the watertight amniotic egg with its series of membranes allowed reptiles to replace amphibians and become the dominant terrestrial vertebrate. Starting with the outermost membrane, the chorion lies just beneath the porous shell of the egg. The amnion encases the developing embryo within a fluid filled cavity. The yolk sac provides food for the embryo via blood vessels connecting to the embryo's gut. The allantois surrounds a cavity into which waste products from the embryo are excreted.

A frog loses its ability to undergo buccal pumping. What must happen to compensate for this loss?

The exchange of gases through the skin must increase.

There are advantages and disadvantages to having an exoskeleton. Complete the following sentences selecting from the terms provided.

The exoskeleton of arthropods is made of chitin, which is both strong and flexible. The exoskeleton provides points of attachment for muscle action. The exoskeleton protects against water loss. To grow the arthropod must undergo ecdysis, during which time they are extremely vulnerable to predators.

Why is ribosomal RNA so useful for cataloging species in microbiome research?

The genes for rRNA are universal and slow to evolve.

Which environment(s) do NOT host a microbiome, as far as we know? (Check all that apply)

The moon,

Which is an example of a microbiome?

The organisms of an individual human's digestive tract.

Based on the gut microbiome study by Blanton, Gordon, and colleagues, what would you predict about a possible therapy that provided the "healthy microbiome" of well-nourished children?

The therapy might allow children in developing nations to extract more nutrition from the same amount of food.

Over 40% of amphibians are threatened with extinction. Considering an amphibian's lifestyle, which of the following explains why amphibians are called "indicator species" of environmental quality?

Their permeable skin and life cycle depends on both water and land.

Why does the microbiome contribute more genes to the hologenome than the host?

There may be thousands of species of microbes, but only one host.

What is the advantage to the segmentation that is exemplified in the Phylum Annelida? (Check all that apply)

Vital structures are repeated in each segment. The annelid may still survive if one segment is damaged. Locomotion is more efficient. Segments can be specialized.

Marsupials are distinguished by

a marsupium.

Bilateria are characterized by

a plane of symmetry that forms mirror images around a vertical plane in the midline.

The organisms of a microbiome may include __________. (Check all that apply.)

archaea bacteria fungi protists

The nearest living relatives of crocodiles and alligators are

birds.

Which of the following are functions of decomposer fungi? Check all that apply.

breakdown of leaf litter breakdown of wood breakdown of dead animals recycling of essential nutrients

Saccharomyces cerevisiae is known to be used for

brewing and winemaking.

Metamorphosis is

changing of one body form to another within a species, such as the change from an aquatic tadpole to a terrestrial frog.

The cell walls of most fungi are composed of

chitin

Some vertebrates like frogs and humans do not have a conspicuous tail, yet even humans have the remnants of one known as the

coccyx.

Cephalization is

concentration of the sensory organs on the anterior end of the body.

The evolution of organisms that use oxygen in their respiration was possible only because of the action of a group of bacteria that produced oxygen and changed the Earth's atmosphere from an anoxic one to one rich in oxygen. That group of bacteria was:

cyanobacteria.

What characteristics are shared by animals and fungi? Check all that apply.

derived from protists absorptive nutrition secrete digestive enzymes

Archaea, Bacteria, and Eukarya are:

domains

The collars on the cells of choanoflagellates have the function of:

filtering bacterial food from the water.

Rhodobacter spheroides has the ability to swim quickly through water toward light, which is necessary for photosynthesis. Such quick swimming is characteristic of __________.

flagella

Birds are different from all other living vertebrates because they

have feathers.

Functions of the mucilage secreted by bacteria include __________. (Check all that apply.)

serving as a defense mechanism contributing to the buoyancy of aquatic species facilitating communication among cells for biofilm formation

Phagocytosis is:

the capture and ingestion of food particles by a cell.

The group of protists to which you are most closely related is:

the choanoflagellates.

The human microbiome is:

the collection of symbiotic microbes living on or within the human body, often performing functions that humans do not possess.

Evolutionarily, the jaws of vertebrates developed from

the third and fourth gill arches of primitive jawless fishes.

Bioremediation is:

the use of microorganisms to break down harmful substances in the environment.

AM fungi are so named because

they produce arbuscular mycorrhizae in the cells of plant roots.

The photosynthetic activity of cyanobacteria takes place in their:

thylakoids.

In addition to the frog, what other organisms are classified as modern amphibians?

toads, salamanders