Assignment summary
in this project, you will analyze claims about the causes of inherited genetic variation. you will then make
your own claim based on prior knowledge. next, you will defend your claim by conducting research to
gather information that supports it. finally, you will present your claim and defense in a typewritten paper.
background information
genetic variation refers to the differences in traits among individuals within a species. genetic differences
populations change over time as they adapt to changes in their environment. individuals with traits
that allow them to adapt to their environment survive and pass their genetic information to offspring.
individuals with traits that do not allow them to survive in their changing environment eventually die out.
new gene combinations are formed during meiosis. meiosis is a cell division process involved in the
production of egg and sperm cells. in meiosis, two processes contribute to differences in genetic
sequence: crossing over and assortment. crossing over happens when genes are exchanged between
chromosomes. in assortment, variation occurs because chromosomes are randomly distributed to the egg
and sperm cells. the meeting of the sperm cell and the egg cell in sexual reproduction is also a random
process; therefore, it creates differences in traits among offspring.
mutations are permanent changes in the sequence of dna. mutations may affect organisms in three
ways. mutations may be beneficial, harmful, or neutral. mutations may occur during the dna replication
process or may be caused by environmental factors such as exposure to chemicals and high-energy light
such as x-rays. the changes in the sequence of a gene may affect the type of protein produced or the
function of a protein.
the expression of traits can be affected by the environment. for example, organisms of a species may
have different fur color based on the differences in the temperature of their habitat. other factors that can
affect variation within a species include diet and lifestyle.

your research paper should start with your claim.
b) in paragraph form, give two examples of scientific information that support each part of your
claim.
c) include a summary paragraph that reiterates your claim and explains how your research
defends your claim.
d) include a list of resources you used in defending your claim.