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A farmer sprays insecticide on his crops to kill unwated insects. Most of the insects die, and the chemicals have the effect of damaging the DNA of the insects that are not killed. What has happened?
Mutations have arisen that may have altered allele frequencies.
The separation of populations by barriers such as rivers, mountains, or bodies of water is called
a plant evolves a high level of poison that enables it to defend itself agasint insects. Soon an insect that perfers to eat this plant evolves an enzyme that breaks down the poison. This is an example of
Charles Darwin called the ability of an organism to survive and reproduce in its specific environment
According to Darwin's theory of natural selection, individuals who survive are the ones best adapted for their environmet. Their survivel is due to the
possession of inherited adaptions that maximize fitness
According to Darwin's theory of natural selection, the individuals that tend to survive are those that have
variations best suited to environmental conditions
One scientist who attempted to explain how rock formations, such as rock layers, for and change over time was
The geographic isolation of two populations of a species tends to increase differences between their gene pools because it
prevents interbreeding between the populations
Darwin noticed that many organisms seemed well suited to
surviving in environments in which they lived
Based on the adaptions Charles Darwin observed in finches and tortoises in the Galapagos, he wondered
if species living on different islands had once been members of the same species
Darwin noticed that many organisms seemed well suited to
surviving in the environments in which they lived
In an experiment, suppose that the wings of fruit flies were clipped short for fifty generations. The fifty-first generation emerged with normal-length wings. This observation would tend to disprove the idea that evolution is based on
inheritance of acquired characteriscs
Which statement about evolution in the Galapagos finches are true
Natural selection on beak size and shape is driven by available food
In the past, mass extinctions encourages the rapid evolution of survivng species
by making new habitats available to them
The situation in which allele frequencies in the gene pool of a population remain constant is called
The species of finches that Charles Darwin found on different Galapagos Islands caried in certain structural adaptations. One of the most significant adaptations that Darwin noted was the
bird's different shaped beaks
In a fox population, the allele frequency of a gene for red fur changes from 20 to 30 percent. What can you say about that population of foxes?
The population is evolving
When a dairy farmer chooses to breed the cows that give the most milk in the herd, the farmers are following the principle of
According to the Hardy-Weinberg principle, genetic equilibrium would be more likely in a oopulation of mice if
no natural selection takes place
What situation might develop in a population having some plants whose flowers open at midday and other plants whose flowers open late in the day?
In a certain population of 100 individuals, one fourth of the individuals have the genotype AA, half have the genotype Aa, and one fourth have the genotype aa. One day, 10 individuals with the genotype aa leave the area and cross a river into a new habitat. Which process has changed the populations gene pool?
Which factor would most likely disrupt genetic equilibrium in a large population?
mating that is not random
The economist Thomas Malthus suggested that
without certain checks on population size, there would soon be insufficient food for the growing human population
The process by which two species evolve in response to changes in each other over time is called
A pattern in which species experience long, stable periods interrupted by brief periods of rapid evolutionary change is called
The type of genetic drift that follows the colonization of a new habitat by a small group of individuals is called
the founder effect
James Hutton's and Charles Lyell's work was important to Darwin because these scientists
suggested that Earth was old enough for evolution to have occurred
Lamarck's ideas about evolution include the concept that differences among the traits of organisms arise a resulf of
the actions of organsisms as they use or fail to use body structures
Which statement abou the members of a population that live long enough to reproduce is consistent with the theory of evolution by natural selection?
They are the ones that are best adapted to survive in their environment
The australian flying phalanger is a marsupial flying squirrel. Its appearance, behavior, environment and diet closely resemble those of the American flying squirrel, a placental mammal. This resembalence is most likely due to
If a mutation introduces a new skin color in a lizard population, which factor might determine whether the frequency of the new allele will increase?
whether the mutation makes some lizards more fit for their environment than other lizards
Although they often live in the same habitat, the American toad breeds earlier in the spring than the Fowler's toad does. What can be inferred from this information?
The two species do not interbreed because of temporal isolation
A single species that has evolved into several different forms that live in different ways has undergone
The frequency of phenotypes for a typical polygenic trait is most often illustrated as
a bell shaped curve
Of the follwoing locations, you would most likely find mosses growing in
shaded ground near a small pond
The flat structure of a leaf blade enables its functionas a photosynthetic organ by
exposing a great surface area to capture energy from sunlight
Bryophytes must live in moist areas because they lack vascular tissue. For what other reason do they need to live in moist areas?
The sperm of bryophytes need water to swim to an egg
If some of the xylem of a young oak tree were destroyed, it would first interfere with the tree's ability to
conduct water to the leaves
Many cacti, such as saguaros and barrel cacti, have large stems and no leaves. What function of leaves is taken on by the stems of such cacti?
They produce food by photosynthesis.
What is one reason that vascular plants are larger than nonvascular plants?
Vascular tissue carries water and nutrients much more efficiently than can be carried by diffusion.
During pollination in seed plants, pollen grains
are carried to female reproductive structures by wind or animals.
In seed plants, what is an important difference between gymnosperms and most angiosperms?
In gymnosperms, male gametophytes and female gametophytes are produced in different structures, while in angiosperms they are usually produced in the same structure.
Which type of vascular tissue carries solutions of nutrients and carbohydrates produced by photosynthesis?
How have the sporophyte and gametophyte changed as plants have evolved?
The gametophyte has become smaller, and the sporophyte has become larger.
Lichens play an important role in soil formation because they
are often the first organisms to enter barren environments.
If plants need oxygen for cellular respiration, then why do plants release oxygen into the atmosphere?
More oxygen is produced during photosynthesis than the plant needs for cellular respiration, so the plant needs to release the extra oxygen.
Seed-bearing plants differ from all other plants in that
their gametes do not require water for fertilization to occur.
Which of the following describes the heartwood of a tree?
old xylem that is no longer conducting water
During fungal reproduction, which of the following processes is first to occur after the nuclei of opposite mating types fuse in order to reduce the chromosome number back to normal for a fungus ?
Which of the following are areas of unspecialized cells in which mitosis produces new cells that are ready for differentiation?
Compare the prey catching (detecting, pursuing, and catching) tools of a jellyfish and a flatworm. Which is the better hunter? Justify your conclusion.
A jellyfish has nematocysts on the tentacles that allow it to "harpoon" prey items that contact it. To assist in moving prey to the tentacles, jellyfish swim using their muscles and nerve net to coordinate movement. This movement has the effect of pulling food particles toward the jellyfish tentacles. A flatworm on the other hand, has chemosensors that detect prey items, a brain to coordinate input from sensors and muscles and cilia to propel the flatworm toward prey. Once it has found the prey, the pharynx will move food into the gastrovascular cavity.
The flatworm would be the better hunter because it not only has effective tools to handle prey, but unlike the jellyfish, it can move toward prey. The jellyfish has to wait in hopes of encountering food items.
Oxygen constantly diffuses from water into a flatworm's body. For this to happen, the concentration of oxygen in its body must be
lower than the concentration of oxygen in the water.
The difference between a protostome and a deuterostome is that
the blastopore in a deuterostome develops into the animal's anus.
A marine biologist discovers a new tiny aquatic invertebrate species that lacks gills.The most reasonable hypothesis would be that the animal gets oxygen through
diffusion across its skin.
Which of the following animals has a body covering that allows for the diffusion of oxygen and carbon dioxide?
Many flatworms can detect changes in the amount of light in their environment using groups of cells called
Parthenogenesis is a method of reproduction in which
an egg develops without being fertilized by a sperm.
The hydrostatic skeleton of a cnidarian depends on which feature in order to support the animal?
Cnidarians evolved a truly unique capability that allowed them to capture prey and defend themselves called the:
Cattle depend on microorganisms in their digestive tract to digest the cellulose in their diets. The cattle and the microorganisms are
When an animal's environment changes, sexual reproduction improves a species' ability to
adapt to new living conditions.
In an animal that is bilaterally symmetrical, which two halves mirror each other?
the left and right sides
A student looks at a slice of tissue on an unlabeled microscope slide. The student concludes the tissue is not from an animal because the cells in the tissue have
Synchronizing gamete (eggs and sperm) release during external fertilization increases the chance that
eggs will be fertilized.
Which chordate characteristic is visible on the outside of an adult cat?
a tail that extends beyond the anus
A gastrovascular cavity is the
body space in some invertebrates where digestive and circulatory functions occur.
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