Biology Second Semester Exam

Dihybrid crosses examine ____ trait(s) at a time.

• one
• two
• multiple
• no

An allele that is expressed only when there are two of the same kind present is called ______

• a testcross
• a monohybrid cross
• recessive
• the law of independent assortment

What is the shape of DNA?

• straight ladder
• double helix
• X shape
• circle and squares

artificial selection

• humans select individuals with the traits they desire
• the ability of a trait to be passed down one generation to the next
• a process in which individuals that have inherited beneficial adaptations produce more offspring than do other individuals

heritability

• humans select individuals with the traits they desire
• the ability of a trait to be passed down one generation to the next
• a process in which individuals that have inherited beneficial adaptations produce more offspring than do other individuals

natural selection

• humans select individuals with the traits they desire
• the ability of a trait to be passed down one generation to the next
• a process in which individuals that have inherited beneficial adaptations produce more offspring than do other individuals

fitness

• a measure of the ability to survive and reproduce
• the study of the distribution of organisms around the world
• resulting in good; helpful

homologous structures

• features that are similar in structure but appear in different organisms and may have different functions
• structures that perform a similar function but are not similar in origin
• small leftover organs or structures that had a function in an early ancestor

analogous structures

• features that are similar in structure but appear in different organisms and may have different functions
• structures that perform a similar function but are not similar in origin
• small leftover organs or structures that had a function in an early ancestor

vestigial structures

• features that are similar in structure but appear in different organisms and may have different functions
• structures that perform a similar function but are not similar in origin
• small leftover organs or structures that had a function in an early ancestor