Exam #3

Which of the following features are used to identify chordates?

A notochord A tail during embryonic development A hollow nerve cord

Imagine you were able to travel back in time to any place you wanted to witness the evolution of humans. Answer the following question related to your journeys. On which continent would you have seen the very earliest members of Homo sapiens?

Africa

Which protist group includes members with plantlike traits such as chloroplasts and multicellularity?

Algae

What is the leading hypothesis for what might have brought about the extinction of the dinosaurs?

An asteroid impact

Serial repetition of segments is a defining characteristic of which worm phylum?

Annelids

What is an exception to the standard biological species concept used to define a species?

Asexual species cannot be distinguished using this concept.

Which evidence supports the hypothesis that four-limbed animals came from fish?

Both fish and four-limbed animals are vertebrates. Fish and four-limbed animals have very similar embryos. DNA analysis shows that fish are tetrapods' closest relatives. The fossil record shows more and more tetrapod-like fish before the appearance of tetrapods about 365 million years ago.

Which of the following best defines microevolution?

Changes in genes within a population over time

Which classification grouping includes the greatest number of species?

Domain

Which grouping includes all of the protists?

Domain Eukarya

Which species is threatening the natural wildlife on the Galapagos Islands?

Humans

Which statement correctly describes the evolution of antibiotic-resistant bacteria?

The presence of an antibiotic in an environment leads to the selection of those individuals that are most resistant to it.

What is a major role that fungi play in ecosystems?

Recycling nutrients from dead organisms back into the food chain

What field of science has as its goal to classify all living things into a hierarchical system of relatedness that runs from most broad to most narrow?

Taxonomy

Prior to the publication of Charles Darwin's book, On the Origin of Species, what was the prevailing public consensus regarding species evolution?

That species were permanent and unchanging

What is radiometric dating?

The process of determining the age of the fossils from radioactive isotopes

Which of the following phyla is the most diverse and numerous?

The arthropods

Many, though not all, mollusks have a shell. What secretes the shell?

The mantle

Which of the following is not an assumption that Darwin made about how evolution acts on populations?

The most fit individuals will always have the most offspring.

What is the smallest unit that can evolve?

The population

A zombie apocalypse wipes out almost the entire human species before the zombie threat is eliminated. Only a group of 100 people who were at a family reunion on an uninhabited island survived. They returned to the mainland completely unaware of what had happened to everyone. Answer the following question regarding the few survivors that now begin to rebuild the human population. Despite an abundance of habitat, why will it be difficult for the human species to recover?

The reduced genetic diversity will make it difficult for the population to adapt to new diseases or other environmental changes.

According to the phylogenetic tree above, which bear is most closely related to the sun bear?

The sloth bear (top of tree)

How did the great transition from fish to tetrapod occur?

The transition occurred gradually over time, so there are many intermediate forms.

Which of the following best describes sponges?

They are asymmetrical, lack tissues, and do not move.

What characteristic do plants, algae, and some bacteria have in common that is not shared with fungi or animals?

They can do photosynthesis.

Which of the following best describes cnidarians?

They have radial body symmetry, tissues, and stinging cells.

Why did Shubin and Daeschler search in the Canadian arctic for fossil evidence of the transition from fish to tetrapods?

They hypothesized that the transitional fossils were in sedimentary rocks older than 365 million years ago, when the first tetrapods appear in the fossil record.

What kind of habitat did tiktaalik live in?

Tiktaalik lived in a warm, freshwater swamp.

Why have we NOT found examples in the fossil record of every animal that ever lived on Earth?

To become a fossil, an animal must be quickly and completely buried in ash or sediment before it has a chance to decompose. Many fossils remain buried. We can only find them when they are exposed by erosion or excavation. To become a fossil, an animal must remain buried for thousands or millions of years until it (and the layer around it) turns to rock.

What is a transitional fossil?

Transitional fossils have features that are intermediate between ancestors and descendants.

How do bony fish regulate buoyancy?

With an air-filled swim bladder

Which of the following is a tetrapod?

a bird a mammal a reptile an amphibian

Flatworms are most closely related to the ________.

annelids

All mammals ________.

have mammary glands

Gastropods are the most numerous group of mollusks and include the ________.

snails and slugs

If two organisms of different species share more similar DNA sequences with each other than with other species, we can conclude that ________.

these two species are very closely related

Which of the following sets of animals are likely to be found on the Galapagos Islands?

tortoises, finches, blue-footed boobies

Animal characteristics (fill in the blank words in caps)

1. One key adaptation of animals was the evolution of a(n) BODY CAVITY, a fluid-filled gap between the outer wall of the body and the outer wall of the digestive system. 2. Cnidarians are the only animal phylum to display RADIAL SYMMETRY, meaning that their bodies can be divided any way through the center point to yield two even halves.All other adult animals display BILATERAL SYMMETRY, meaning that their bodies can only be sliced lengthwise through the midline to produce two even halves. 3. All animals are EUKARYOTES, organisms with cells that are relatively large, complex, and contain membrane-enclosed organelles such as the nucleus. 4. All animals eat other organisms in order to gain building materials for the body. This makes them HETEROTROPHS, since they obtain necessary energy and chemical building blocks from the environment. 5. All animals except sponges have TISSUES, groups of cells that work together to perform a specific function.

How long ago were the organisms that produced the oldest fossil records alive?

3.5 Billion

Where are the Galapagos Islands located?

600 miles west of Ecuador, near the equator

Natural selection

Environmental change- drought causes a habitat to turn dry and brown Selective pressure- Green beetles are more visible than brown beetles, so the birds eat more green beetles Change in population- Brown beetles survive to reproduce more than green beetles do. The brown allele increases in frequency

What term describes the failure of one species' sperm to fertilize the egg of a different species?

Gametic incompatibility

Mechanisms of evolution

Gene flow- new individuals move into a population Natural selection- camouflage enables this insect to evade predators Genetic drift- by chance, some wildflowers in this population reproduce, while others do not

Which of the following mechanisms can drive evolution?

Genetic drift Natural selection Mutations

Which of the following most often should lead to allopatric speciation?

Habitat isolation

Which one of the following is a defining characteristic of animals but not of plants?

Heterotrophic

What does "fitness" mean when speaking in terms of evolution?

How many offspring an individual produces

Tiktaalik had a combination of fishlike and tetrapod-like characteristics. Which were the tetrapod-like characteristics?

Interlocking ribs flat head with eyes on top a neck

What characterizes terrestrial tetrapods?

Lives on land, has four limbs

The older fossils are typically found in the ________ sediments.

Lower

Which of the following is evidence for evolution?

Mosquitoes becoming resistant to pesticides Cells with common features and chemically similar DNA Bacteria becoming resistant to antibiotics over time (All)

What is the original source of variation that natural selection can act upon?

Mutation

The Galapagos Islands were the first place on Earth to _____.

be declared a world heritage site

Tourism on the Galapagos Islands is being restricted by requiring tourists to _____.

be escorted by trained guides at all times

Evolution can be best defined as ________.

change in allele frequency in a population

The echinoderms are most closely related to the ________.

chordates

The rapid diversification of species seen in the fossil record followed by long periods of stasis is part of the ________ model of evolution.

punctuated equilibrium