CFA #11 Corrections

Which TWO statements best describes a current understanding of natural selection?

• Natural selection influences the frequency of an adaptation in a population.

• New mutations of genetic material are due to natural selection.

• Natural selection has been discarded as an important concept in evolution.

• For natural selection to occur, some organisms must be more likely to survive and reproduce.

• Changes in the gene frequencies due to natural selection have little effect on the evolution of species.

The Canyon spotted whiptail and the Sonoran spotted whiptail are lizard species that live in the same desert. The Canyon spotted whiptail is composed of males and females that reproduce sexually. The Sonoran spotted whiptail is an all-female species that reproduces asexually.  Which lizard species is more likely to survive a drastic sudden change in climate?

• Sonoran spotted whiptail because all members of the species can reproduce

• The Sonoran spotted whiptail because their genetic similarities will keep the species stable

• The Canyon spotted whiptail because their genetic differences improve their chances of adapting

• The Canyon spotted whiptail because species with male and female members produce more offspring

The ptarmigan is a seed-eating Arctic bird that changes the color of its feathers with the change of the seasons. In the summer it is a brownish color, and in the winter it is white.  Which of the following provides the best explanation for this change?

• The color change helps it find food more easily.

• The color change helps protect it from predators.

• The color change helps it regulate its body temperature better.

• Brown feathers are better than white ones for flying during mating season.

Male fiddler crabs attract females by quickly waving their large front claw. If a claw is lost in a fight or accident, they quickly grow a hollow claw of equal length. Because the new claw is lighter, they can wave it faster. A male fiddler crab is shown below.  The new claw probably helps the male fiddler crab to-

• successfully reproduce

• fight more successfully

• maintain homeostasis

• evolve into a new species

The sequence A through E represents stages of ecological succession in a given area.  What caused succession to occur in stages A through E?

• importation of organisms that have no natural enemies

• each community modifying the environment

• urban development disrupting natural habitats

• technological oversights leading to air pollution

A gradual change in plant communities of a sand dune ecosystem can result in -----

• reduced symbiotic relationships between producers and bacteria

• reduced energy consumption by consumers

• greater erosion rates

• greater species diversity

Sand dunes along the coast are formed of bare sand. Eventually, grasses take root on the dunes. Over time, larger plants such as shrubs and trees are able to grow a the edge of the sand dune ecosystem. This gradual change in plant communities of a sand dune ecosystem best describes which of the following processes?

• Natural Selection

• Adapting

• Primary Succession

• Secondary Succession

Answer explanation

Key word =bare!!!

White clovers, Trifolium repens, are plants that are native to Europe and Central Asia and are able to produce the poison cyanide within their cells.  Skunk cabbage, Symplocarpus foetidus, is a plant that is native to eastern North America and can produce a chemical that makes it have a strong, foul odor and bitter taste.  

 

The chemicals produced by both the white clovers and skink cabbages are adaptations that allow them to ----

• attract more pollinators

• survive a long-term drought

• protect against herbivores

• grow better in colder habitats