Researchers are investigating the incidence of algal blooms in neighborhood ponds. In summer, they collect water samples from over 100 neighborhood ponds in Dallas, Texas and surrounding cities. They also surveyed residents in each neighborhood to collect data such as average lot size, average home value, average resident income, and lawn care methods. The researchers found that neighborhoods with large lots, high home values, and high income levels were likely to use automatic sprinklers and synthetic fertilizers on their lawns. These same neighborhoods were very likely to have abundant algae in their ponds. Based on this research, which conclusion below provides the best explanation for why algae proliferate in neighborhood ponds? a. Automatic sprinklers may house algae and may spray into neighborhood ponds.
b. High income neighborhoods are less likely to treat their ponds with chemicals that prevent algae growth.
c. Lawn fertilizer that washes into neighborhood ponds likely causes algae to become more abundant.
d. Neighborhoods with expensive homes typically have larger, deeper ponds that are more likely to support algae proliferation.
e. Large lot sizes likely provide algae with extra room to grow, and the algae then washes into the pond.

c. Lawn fertilizer that washes into neighborhood ponds likely causes algae to become more abundant.

Explanation:

Eutrophication is a natural phenomena in which the algal growth occurs in the water body due to increase in concentration of the fertilizers and manures being drained from the agricultural land into water. This causes decrease in oxygen level in water, and the aquatic animals in water will not survive due to scarcity of water.

According to the given situation, the growth of algae in the neighboring ponds is due to the drainage of lawn fertilizers into the neighboring ponds being washed from the lawns. This causes algae to grow abundantly in ponds.

the african cheetah.

this species has a relatively low level of genetic

variation because the population was reduced to a small size approxi-

mately 10,000 to 12,000 years ago.

chapter   outline

24.1

genes in populations and the hardy-

weinberg equation

24.2

factors that change allele and genotype

frequencies in populations

24.3     sources of new genetic variation

population   genetics

24

until   now,   we   have   primarily   focused   our   attention   on   genes  

within   individuals   and   their   related   family   members.   in   this  

chapter   and   chapters   25   and   26   ,   we   turn   to   the   study   of   genes   in  

a   population   or   species.   the   field   of

population   genetics

  is   con-

cerned   with   changes   in   genetic   variation   within   a   group   of   indi-

viduals   over   time.   population   geneticists   want   to   know   the   extent  

of   genetic   variation   within   populations,   why   it   exists,   and   how   it  

changes   over   the   course   of   many   generations.   the   field   of   popu-

lation   genetics   emerged   as   a   branch   of   genetics   in   the   1920s   and  

1930s.   its   mathematical   foundations   were   developed   by   theoreti-

cians   who   extended   the   principles   of   gregor   mendel   and   charles  

darwin   by   deriving   formulas   to   explain   the   occurrence   of   geno-

types   within   populations.   these   foundations   can   be   largely   attrib-

uted to three scientists: sir ronald fisher, sewall wright, and j. b. s.

haldane.   as   we   will   see,   support   for   their   mathematical   theories  

was provided by several researchers who analyzed the genetic com-

position   of   natural   and   experimental   populations.   more   recently,  

population   geneticists   have   used   techniques   to   probe   genetic  

variation   at   the   molecular   level.   in   addition,   staggering   advances  

in   computer   technology   have   aided   population   geneticists   in   the  

analysis   of   their   genetic   theories   and   data.   in   this   chapter,   we   will  

explore   the   genetic   variation   that   occurs   in   populations   and   con-

sider   the   reasons   why   the   genetic   composition   of   populations   may  

change over the course of several generations