Second Midterm Flashcards
Which of the following characteristics is true of all protists?
contain a nucleus
Biologists suspect that endosymbiosis gave rise to mitochondria before plastids partly because
all eukaryotes have mitochondria (or their remnants) whereas many eukaryotes do not have plastids
A particular species of protist has obtained a chloroplast via secondary endosymbiosis. How can you tell?
the chloroplasts have three or four membranes
Biologists have long been aware that the defunct kingdom Protista is paraphyletic. Which of these statements is most consistent with this conclusion?
some protists, all animals, and all fungi share a protist common ancestor, but these organisms are currently assigned to three different kingdoms
What does the presence of a coal mine in an area indicate about that region’s geologic history?
marsh or boggy habitats were once found there
The phylogenetic tree supports which scientific understanding of evolution of green plants?
the transition from water to land occurred just once
Biologists hypothesize that the first land plants had a low, sprawling growth habit. Which of the following statements is part of the logic behind this theory?
to obtain water, early plants had to keep their tissues in direct contact with moist soil
Artificial selection has produced a distinct set of changes that have been observed as wild forms of plants have been brought under cultivation. Which of the following represents an example of artificial selection?
diversification of the wild species Brassica oeracea into the domesticated varieties of cabbage-family plants
Consider the following points (a) All excavates live in environments where oxygen is low, (b) All excavates lack mitochondria, and (c) All excavates have some mitochondrial genes. Based on this info which of the following is true of excavates?
Their ancestors had mitochondria but they were lost over time
According to the endosymbiotic theory, why was it adaptive for the larger (host) cell to keep the engulfed cell alive, rather than digesting it as food?
the engulfed cell provided the host cell with ATP
Sequence for alternation of generations
gametophyte, gamete, fusion, sporophyte, spore
Encouraging the growth (via nutrient fertilization) of photosynthetic protists in marine environments may help reduce global warming because ___
photosynthetic protists fix atmospheric carbon dioxide, decreasing atmospheric carbon dioxide levels
Imagine that there are 25 different species of protists living in a tide pool. Some of these species reproduce both sexually and asexually, and some of them can reproduce only asexually. The pool gradually becomes infested with disease-causing viruses and bacteria. Which species are more likely to thrive in the changing environment?
the sexually reproducing species
According to the endosymbiotic theory, why was it adaptive for the larger (host) cell to keep the engulfed cell alive, rather than digesting it as food?
the engulfed cell provided the host cell with ATP
Which of the following was derived from an ancestral cyanobacteria?
chloroplast
A snail-like, coiled, porous (test) of calcium carbonate is a characteristic of
foraminiferans
Which of the following situations would be most favorable to the reestablishment of resident zoochlorellae, assuming compatible Chlorella are present in P. bursaria’s habitat?
abundan light, abundant bacterial prey
Which of the following is most likely to lead to paralytic shellfish poisoning?
dinoflagellates
According to the fossil record, plants colonized terrestrial habitats ___
in conjunction with fungi that helped provide them with nutrients from the soil
About 450 mya, the terrestrial landscape on Earth would have ___
had non-vascular green plants similar to liverworts forming green mats on rock
What evidence do paleobotantists look for that indicated the movement of plants from water to land?
waxy cuticle to decrease evaporation from leaves
Which set contains the most closely related terms?
megasporangium, megaspore, egg, ovule
Dicots
2 seed leaves, netlike veins, ring vascular bundle, taproot, multiples of 4 or 5
Monocots
1 seed leaf, parallel veins, complex vascular bundles, fibrous roots, multiples of 3
If a fern gametophyte has both male and female gametangia on the same plant, then it ___
belongs to a species that is homosporous
In plants, which of the following are produced by meiosis?
haploid spores
Arrange male pine tree structures from largest to smallest
sporophyte, pollen cone, microsporangia, microspores, pollen nuclei
What is true about the genus Sphagnum?
it is an important carbon sink, reducing atmospheric carbon dioxide
The trees grew vigorously, produced healthy flowers in profusion but set no fruit. Consequently, what is the likely source of the problem?
pollination failure
Why are mycorrhizal fungi superior to plants at acquiring mineral nutrition from the soil?
Hyphae are 100 to 1000 times smaller than plant roots. Fungi secrete extracellular enzymes that can break down large molecules. Fungi can transport compounds through their mycelium from areas of surplus to areas of need (All of the above)
Based on the idea that fungi have pores between their cell walls allowing cytoplasm to move from one end of the mycelium to the other, which of the following hypotheses is the most plausible?
Carbon could travel from one plant to another through a single mycorrhizal fungus
Carbon 14 in birch and carbon 13 in Douglas. If sugars made by one plant can travel through a mycorrhizal fungus and be incorporated into the tissues of another plant then ___
Carbon 14 is found in the Douglas and carbon 13 in the birch
Imagine that sexual reproduction could occur between hyphae that were the same mating type. How might this affect rates of evolution in fungi?
rates of evolution would be lower because genetic variation would be lower
What would this mean for the evolution of fruiting bodies for the group Dikarya?
the group Dikarya has members that lost the trait of complex multicellular fruiting bodies
Why are terrestrial fungal mycelia nearly always found within their food sources (underground, within wood, inside the bodies of dead organisms)?
their high surface area, which is so efficient for absorptive feeding, makes them prone to drying out
Biologists once considered sponges to be colonies of single-celled protists because sponge cells are able to reaggregate after being dissociated. What evidence may have helped them to realize that sponges are actually animals and not colonial protists?
they have extracellular matrix surrounding their cells
Both animals and fungi are heterotrophic. What distinguishes animal heterotrophy from fungal heterotrophy is that only animals derive their nutrition by ___
ingesting it
What distinguishes a coelomate animal from a pseudocoelomate animal is that coelomates ___
have a body cavity completely lined by mesodermal tissue
You have before you a living organism, which you examine carefully. Which of the following should convince you that the organism is an acoelomate?
Muscular activity of its digestive system distorts the body wall
Biologists once hypothesized that animal limbs were not homologous. What changed their minds?
the discovery of the Dll gene is present and similarly expressed in a very wide variety of animals
At which stage of a basidiomycete’s life cycle would reproduction be halted if an enzyme that prevented the fusion of hyphae was introduced?
plasmogamy
A cell has two haploid nuclei
dikaryotic
Which of the following is an important role for fungi in the carbon cycle?
fungi help release fixed carbon back to the environment for other plants and photosynthetic organisms to utilize
Long, branching fungal filaments are called ___
hyphae
What do biologists cite as the primary benefit of the evolution of a coelom in animals?
the hydrostatic skeleton, allowing greater range of motion
Due to its unusual habitat (inside the digestive tracts of other animals), the tapeworm lacks
a mouth and a digestive tract
An organism that exhibits cephalization probably also ___
is bilaterally symmetrical
The digestive system of most animals is lined with cells through which nutrients are absorbed. What is the embryonic origin of these cells?
endoderm
Most fish deposit fertilized eggs, but some sharks keep the fertilized egg inside the female until she gives birth to a relatively well-developed pup. These sharks would be characterized as ___
ovoviviparous
What do sporophytes produce?
spores
T or F: All gymnosperms produce seeds.
true
T or F: Ferns are among the first vascular plants to evolve
true
The term “alternation of generations” refers to
the cycling between multicellular haploid and diploid stages of life
T or F: The haploid phase in animals only exists as a gamete (multicellularity), while the diploid phase is always a single cell phase
false
In plants, a gametophyte ___
is always haploid, produces gametes, is always multicellular
What is the endosperm in angiosperms?
a triploid tissue
Stamenopiles consists of two common photosynthetic groups
Diatoms and Phaeophyta
What is the evolutionary advantage of pollen?
fertilization does not require water
Which of the following plant structures or processes was not an important adaptation specific to life on land?
photosynthesis
Which of the following is an important role for fungi in the carbon cycle?
fungi release fixed carbon back to the environment for other plants and photosynthetic organisms to utilize
All fungi are
heterotrophic
Based on the idea that fungi have pores between their cell walls, which allow cytoplasm to move from one end of the mycelium to the other, which of the following hypotheses is most plausible?
If a single mycorrhizal fungus formed symbiotic associations with more than one tree, carbon could travel from one plant to another.
When a mycelium infiltrates an unexploited source of dead organic matter, what are most likely to appear within the food source thereafter?
fungal enzymes
The adaptive advantage associated with the filamentous nature of fungal mycelia is primarily related to ___
an extensive surface area well suited for invasive growth and absorptive nutrition
Basidiomycetes are the only fungal group capable of synthesizing lignin peroxidase. What advantage does this group of fungi have over other fungi because of this ability?
this fungal group can break down the tough lignin, which cannot be harnessed for energy, to get to the more useful cellulose
Some fungal species can kill herbivores while feeding off of sugars from its plant host. What type of relationship does this fungus have with its host?
mutualistic
What is the major difference between graph f and other plant species?
Bromus erectus is unaffected by AMF directly
In most fungi, karyogamy does not immediately follow plasmogamy, which consequently ___
results in heterokaryotic cells
To speed the arrival of conditions necessary for plant growth, the billionaire might be advised to aerially sow what over the island?
soredia
Animal kingdom is ___
monophyletic
The central nervous system is lacking in animals that have ___
radial symmetry
Endoderm is where on an earthworm body plan as a drinking straw within a pipe
lining the straw
What would you expect to happen if researchers supplied an enzyme that blocked the expression of the Dll gene?
the developing embryo would have no appendages
Which of the following would you use to label the horizontal axis?
number of choanocytes per sponge
Sponges are most accurately described as
suspension feeders
What feature of cnidarians most likely evolved simultaneously with the evolution of toxins?
a slow-moving or sessile lifestyle in the adult
A radially symmetrical animal that has two embryonic tissue layers is?
cnidaria
Which characteristic is shared by cnidarians and flatworms?
digestive system with a single opening
Studies fertilized eggs and find that the blastophore becomes the mouth. The embryo develops into a trochophore larva and eventually has a coelom.
mollusc
The heartworms that can accumulate within the heart of dogs and other mammals have a pseudocoelom, an alimentary canal, and an outer covering that is occasionally shed. To which phylum does the heartworm belong
nematoda
Skeletal structures that are entirely or partly composed of calcium carbonate can be found in some members of the following
sponges, coral, molluscs, arthopods,
An arthropod has all the following characteristics except A) protostome development. B) bilateral symmetry. C) a pseudocoelom. D) three embryonic germ layers. E) an open circulatory system.
C
All of the following are characteristics of adult arthropods except A) an exoskeleton. B) hemolymph. C) jointed appendages. D) a heart. E) a coelom.
E
Among the invertebrates, arthropods are unique in possessing A) a cuticle. B) a ventral nerve cord. C) open circulation. D) wings. E) segmented bodies.
D
The presence or absence of mandibles can be used to distinguish between A) insects and centipedes. B) insects and crustaceans. C) insects and millipedes. D) insects and spiders. E) centipedes and millipedes.
D
A shared derived characteristic for members of the arthropod subgroup that includes spiders would be the presence of A) chelicerae. B) an open circulatory system. C) an exoskeleton. D) a cuticle. E) a cephalothorax.
A
You find a small animal with eight legs crawling up your bedroom wall. Closer examination will probably reveal that this animal has A) antennae. B) no antennae. C) chelicerae. D) A and C E) B and C
E
Which of the following characteristics most likely explains why insects are so successful at dispersing to distant environments? A) hemocoel B) wings C) jointed appendages D) chewing mandibles E) internal fertilization
B
A terrestrial animal species is discovered with the following larval characteristics: exoskeleton, tracheal system for gas exchange, and modified segmentation. A knowledgeable zoologist would predict that its adults probably also would have A) eight legs. B) two pairs of antennae. C) a sessile lifestyle. D) an open circulatory system. E) parapodia.
D
Which of the following is a characteristic of adult echinoderms? A) secondary radial symmetry B) spiral cleavage during early embryonic development C) gastrovascular cavity D) exoskeleton E) a lophophore
A
What is true of echinoderms? A) They have an endoskeleton of hard calcareous plates. B) Tube feet provide motility in most species. C) They have a pseudocoelom. D) Only A and B are true. E) A, B, and C are true.
D
All of the following animal groups include terrestrial life forms except A) Mollusca. B) Crustacea. C) Echinodermata. D) Arthropoda. E) Annelida.
C
In a tide pool, a student encounters an organism with a hard outer covering that contains much calcium carbonate, an open circulatory system, and gills. The organism could potentially be a crab, a shrimp, a barnacle, or a bivalve. Which structure below would allow for the most certain identification? A) a mantle B) a heart C) a body cavity D) a lophophore E) eyes
A
Protostomes that have an open circulatory system and an exoskeleton of chitin
arthropods
protostomes with a unique drape of tissue that may secrete a shell
molluscs
diploblastic phylum of aquatic predators
cnidaria
deuterostomes that have an endoskeleton
enchinoderms
protostomes that have a closed circulatory system and obvious segmentation
annelids
