Biology District Unit 3 Exam

Which table correctly describes the difference between DNA and RNA?

The process by which DNA is transferred to a messenger RNA (mRNA) is called

What is the process by which DNA copies itself into new cells?

What is the function of RNA?

Which molecule is produced during transcription?

How do the functions of DNA and RNA differ?

Sickle-shaped red blood cells result from a mutation in the gene that codes for hemoglobin. This mutation results in
sickle-cell anemia. A partial sequence of bases from a normal hemoglobin gene and a sequence that results in sicklecell anemia are shown below.

Normal hemoglobin:         T-G-A-G-G-T-C-T-C-C-T-C

Sickle-cell hemoglobin:    T-G-A-G-G-T-C-A-C-C-T-C

What type of mutation is depicted in this sequence?

A mouse in a field eats food containing high amounts of a certain pesticide. The pesticide causes a mutation
to occur in the liver cells of the mouse. Which of the following statements is most likely correct?

Ezra was born with an extra chromosome number 21 due to a process called nondisjunction, which is shown
below.

Ezra has Down syndrome. Ezra’s sister does not have an extra chromosome number 21 and so does not have
Down syndrome. What conclusion about nondisjunction can be drawn?

The diagram shows the process of crossing over.

Which claim about crossing over in chromosomes is best supported by the diagram?

Which statement is true about mutations?

The Punnett square in the figure above shows that the gene for pea shape and the gene for pea color assort independently.  Which statement summarizes the law of independent assortment?

A boy has brown hair and blue eyes. His brother has brown hair and brown eyes. The fact that they have
different combinations of traits is best explained by the concept of

Why is the process of meiosis so important?

A red rose bush cross-pollinates a white rose bush. The offspring have white flowers with red streaks. What type of inheritance is this?

In the dihybrid cross for pea plants shown below, R is dominant for round peas, r is recessive for wrinkled
peas, Y is dominant for yellow peas, and y is recessive for green peas.

Which statement could be accurately made about the offspring of this cross?

Which Punnett square demonstrates a pattern of incomplete dominance?

A student draws a Punnett square where two parents that are heterozygous for dimples are crossed. Dimples (D) are dominant to no dimples (d).

Using the Punnett square, what is the percent chance that the offspring will have dimples?

Which of the following BEST explains an advantage in a rapidly changing environment of species that utilize
sexual reproduction over those that utilize asexual reproduction?

The diagram shows a single-celled organism reproducing.

What is an advantage of this type of reproduction?

Being genetically identical to the parent is most advantageous for organisms in which situation?

A male and female have a child that has three copies of chromosome 18. Although both parents are unaffected, their
doctor claims that the disorder associated with having an extra chromosome 18 is the result of a chromosomal mutation
in cells that carry inherited material. Which argument supports this claim?

Today, the common type of banana we buy and eat is a Cavendish banana.  They arose from chance mutants that were produced sexually from wild banana plants.  The Cavendish banana is infertile and can only be produced by cloning from root shoots.  Large commercial growers worldwide now plant only the mutant type.  Some information about both types of banana is recorded in the table.

Part A

Why are scientists warning that exclusively growing this mutant type by asexual reproduction presents a serious disadvantage?

Today, the common type of banana we buy and eat is a Cavendish banana.  They arose from chance mutants that were produced sexually from wild banana plants.  The Cavendish banana is infertile and can only be produced by cloning from root shoots.  Large commercial growers worldwide now plant only the mutant type.  Some information about both types of banana is recorded in the table.

Growers on large banana farms that supply food commercially have chosen to limit their plantings exclusively to Cavendish banana plants.  What advantage is likely cited by the growers for continued planting of these asexually produced crops year after year?

Students studied Mendel’s laws of segregation and independent assortment.  They created a Punnett square to show a cross between a homozygous furred mouse (FF) and a homozygous furless mouse (ff).  The students then created a second Punnett square for a cross between two heterozygous F1 mice.

Which question could be answered using the information from the Punnett squares?