Biology GMA Study Guide

23. Bromothymol blue (BTB) is a pH indicator that is also used to detect carbon dioxide (CO2). BTB is blue when pH is basic and CO2 is low. BTB is yellow when pH is acidic and CO2 is high. BTB is green when pH is neutral. A group of students are planning to perform an investigation in which they will place either a stalk of the aquatic plant elodea or a snail in a test tube that contains water with a neutral pH of 7 and BTB. The students will also include a test tube that contains elodea and a snail. Observing color change once the tubes have been placed under a growth light for several hours will allow the students to answer which TWO of the following questions?

• Does photosynthesis performed by elodea remove CO2 from the water?
• Does cellular respiration occur at a higher rate than photosynthesis in the tube with only elodea?
• Do both elodea and snails require oxygen to survive?
• Does elodea produce oxygen during photosynthesis?
• Do snails respire faster when placed in a tube with elodea?

25. Which row in the chart above represents the most likely changes in the atmosphere due to widespread deforestation?

• Row 1
• Row 2
• Row 3
• Row 4

26. Students created the following model using paper plates, flat wooden sticks, cotton swabs, and construction paper. Which statement correctly uses the model to explain how mitosis maintains genetic continuity?

• The chromosomes in cell 1 are the same as in cells 6 and 7.
• Option 2
• When the nuclear membrane reforms in cell 5, each nucleus becomes diploid in number.
• The independent assortment that is represented in cell 2 ensures that cell 3 has the correct number of chromosomes.

41. Which statement best explains the events represented in this diagram?

• A gene mutation caused the cells to become muscle cells.
• The growth resulted from the introduction of a vaccine.
• A gene mutation caused abnormal mitotic cell division.
• The growth results from uncontrolled meiotic cell division.

56. Which description explains the role of the tRNA in the process shown in this model?

• the model delivers amino acids to the ribosome so that they can be added to the developing peptide.
• The model recognizes the stop codon of a developing peptide so that no new amino acids are added.
• The model signals the release of the peptide from the ribosome once all of the amino acids have been added.
• The model scans the developing peptide to make sure that the sequence of the amino acids matches the mRNA.

58. Hemoglobin is a protein found in red blood cells of vertebrates and in the plasma of many invertebrates. The function of this protein is to transport oxygen throughout the body and to bring carbon dioxide back to be expelled from the organism. If the amino acid sequence of the protein is altered, the mutated protein is not as efficient at carrying oxygen as is the normal hemoglobin. Which argument is supported by this information?

• The mutated hemoglobin protein can still carry carbon dioxide to be expelled from the organism.
• Hemoglobin must be a simple molecule because it is found in both vertebrates and invertebrates.
• Structural changes of hemoglobin affect its ability to carry oxygen indicating that the shape of a protein is important to its function.
• Normal hemoglobin must be a larger molecule than the mutated hemoglobin since it has sufficient space to attach to and carry both oxygen molecules and carbon dioxide molecules.

59. 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?

• A mutation occurred when crossing over caused chromosome 18 to be replicated twice during meiosis, allowing one parent to donate two copies of chromosome 18 to the child.
• A nondisjunction mutation was caused by the improper separation of the genetic material during meiosis, allowing the gamete of one parent to donate two copies of chromosome 18 to the child.
• A substitution mutation during replication allowed the genetic material of chromosome 18 to replace the genetic material of a nearby chromosome, causing the child to have three copies of chromosome 18.
• An insertion mutation during replication allowed the genetic material of chromosome 18 to be inserted into the genetic material of another chromosome, causing three copies of chromosome 18 to be made.

64. Agriculture companies produce plants that have genetic modifications that give the plants desired traits, such as resistance to drought or pests. Which question would gather information about an ethical consideration of genetically modified plants?

• Will these plants cause pollinators to avoid large areas of land?
• Can the amount of excess food produced by these plants be calculated?
• Can the genetic modifications of these plants be acquired by noxious plants?
• Will these plants require more land to grow than an equal amount of non-genetically modified plants require?

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

• The loss of an adequate Cavendish banana seed supply could result in extinction of this variety.
• The changes in characteristics from a parent plant to a clone will produce inconsistent plants that are less healthy.
• The lack of genetic variability among clones puts the whole species at increased risk of extinction through a catastrophic disease or pest.
• The increasing number of homologous sets of chromosomes with each successive generation of clones will eventually result in widespread death of banana plants

69. 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 hairless mouse (ff). The students then created a Punnett square for a cross between two heterozygous F1 mice. Which question could be answered using the information from the Punnett squares?

• Can furred mice produce furless mice?
• How many mice will be produced in the F1 generation?
• Will fewer furless mice survive to adulthood than furred mice?
• Are furred mice the best organism to use for this investigation?