Biology GMA Study Guide

Ruby-throated hummingbirds are found throughout eastern North America. They are omnivores, feeding on nectar, pollen, tree sap, insects, and spiders. They get all the water they need from nectar. Most nests are in forested areas, citrus groves, marshes, and scrubland. The hummingbirds breed in the spring and the summer, and females raise one to three broods per breeding season. Most of the hummingbirds migrate to Mexico or Central America for the winter. Many fly nonstop for 20 hours to cross the Gulf of Mexico. However, increasing numbers of the hummingbirds have begun to winter north of the gulf. Researchers have documented that the hummingbirds’ winter range has expanded northward by about 300 km in recent years. Which explanation BEST predicts the ability of the hummingbirds to survive their first winter in this new environment?

• Finding suitable nesting materials and sites is the most important task the hummingbirds must accomplish because they must produce offspring.
• Finding a sufficient supply of flowering plants, flowering trees, and insects is the most important task for the hummingbirds because they need food to survive.
• Finding bodies of water is the most important task for the hummingbirds because they need to supplement the supply of nectar if it is inadequate to provide all the calories the hummingbirds need to survive.
• Finding mates to allow the hummingbirds to lay fertile eggs and have two parents to feed the new hatchlings is the most important task for the hummingbirds because they need to ensure there is a new generation of hummingbirds in the region

Scientists have studied a type of phytoplankton species. These phytoplankton are an important part of marine food webs and are major primary producers. As all organisms are regulated by their environment, so are the plankton. The scientists looked at the relationship between the populations of the phytoplankton and viruses found in the same environment. They created three environments in a laboratory setting to collect data on the growth of the plankton population and the viruses for a period of time and graphed the results once they were averaged, as shown below. The scientists claim that the growth and stability of the population of plankton were affected by the viruses. Using the information given, which TWO arguments support this claim?

• As the phytoplankton population increased, the number of viruses increased because the phytoplankton were the hosts to the viruses and replicated the viruses’ genome.
• The plankton population decreased as the number of viruses increased because the cells of the phytoplankton were destroyed as the viruses used them to increase the number of viruses in the environment.
• The phytoplankton population was unable to absorb the light necessary for growth because the viruses covered the surface of the water.
• The phytoplankton population was affected by the viruses because the viruses were competitors for the food sources in the environment.
• As the phytoplankton population increased, the number of viruses began to increase because the phytoplankton were consumed by the viruses.

Students are studying factors that affect population sizes. They plan an investigation to explore the effect of the starting population size on growth rate and on the carrying capacity of the environment. The students select duckweed for the experiment because it has continuous growth. Duckweed is a free-floating aquatic plant that at times clogs waterways. It most commonly reproduces asexually by producing a new leaf-like structure that breaks off from the parent plant once the new structure has roots. The students agree on a hypothesis stating that the greater the number of individuals of the starting population, the faster the population will reach carrying capacity. The following procedure is developed by the students. Analyze the data from the investigation to identify which statement BEST explains the results.

• Each population reached the carrying capacity at different weeks.
• Populations 9 and 10 were unable to reach the carrying capacity before the end of the investigation period.
• Populations 11 and 12 reached carrying capacity at week 5 because there were fewer plants for the rest of the investigation period.
• The populations had different starting population numbers that grew at the same rate and reached their carrying capacities at the same time.

Invasive insect species can cause severe damage to native trees and plants. Some insects bore into live trees and then get transported when trees are cut for use in numerous products. Wooden crates used for packing materials may be infested with insects or eggs that are then transported over long distances. What is one safe and practical way that people can act responsibly to prevent spreading potentially harmful and invasive insects?

• Store unused firewood from one winter until the next winter in a shaded grassy area to starve the insects and stop their propagation.
• Spray all wooden products with pesticide before bringing them into homes or other buildings to kill the insects before they can enter structures.
• Chop down trees suspected of being infected and use a wood chipper to make mulch for landscaping to chop up some of the insects before they can infect other trees.
• Buy local firewood near campsites instead of transporting raw wood from one area to another and then leave any extra for the next camper to prevent transferring the insects in infected wood.

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

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?

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.
• Crossing-over occurs in cell 4, which increases the genetic diversity in cells 6 and 7.
• 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.

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.

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.

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.