A mycologist performed an experiment to determine the effect of methanol on the mold Neurospora crassa.

1,500 Neurospora spores were divided evenly into five groups of three large glass test tubes each. Then each test tube was filled with 5.0 mL of liquid nutrient solution and either 0 mL, 0.5 mL, 1.0 mL, 1.5 mL, or 2.0 mL of methanol. The tubes were placed in an incubator at 28oC overnight to germinate, and then their aerial growth was marked beginning the next morning and every twelve hours thereafter for two days.

Table 1 shows the average growth data with hours representing the morning after germination and hours representing the end of the two-day experiment.

In general, the results of the study suggest that Neurospora cultures prepared in liquid media can tolerate at least how many milliliters of methanol and still grow?

| | G | g | | | ---- | -- | -- | | g | Gg | gg | | g | Gg | gg |

Scientist’s believe they have found the gene accountable for intelligence. The allele “G” is dominant, and the allele “g” is recessive. The intelligence gene is optimally expressed in the homozygous recessive form. The chart above shows the trait in the heterozygous form and the homozygous form. The form “gg” is from the mother, and “Gg” is from the father. The parents want to know what the gene might look like in their child.

According to the chart above, what are the chances of the child inheriting the optimal form of the gene?

| | G | g | | | ---- | -- | -- | | g | Gg | gg | | g | Gg | gg |

Scientist’s believe they have found the gene accountable for intelligence. The allele “G” is dominant, and the allele “g” is recessive. The intelligence gene is optimally expressed in the homozygous recessive form. The chart above shows the trait in the heterozygous form and the homozygous form. The form “gg” is from the mother, and “Gg” is from the father. The parents want to know what the gene might look like in their child.

According to the data given, what could one infer about the phenotype for "Gg?"

| | G | g | | | ---- | -- | -- | | g | Gg | gg | | g | Gg | gg |

Scientist’s believe they have found the gene accountable for intelligence. The allele “G” is dominant, and the allele “g” is recessive. The intelligence gene is optimally expressed in the homozygous recessive form. The chart above shows the trait in the heterozygous form and the homozygous form. The form “gg” is from the mother, and “Gg” is from the father. The parents want to know what the gene might look like in their child.

What genotypes would two parents want to have to increase their chances of a child exhibiting an optimal intelligence phenotype?

The chart above shows the height growth of three different plant species after a period of 2 weeks. Each plant species was grown in 4 different soil mediums. All the plants were grown in the same environment with equal amounts of light, water, and oxygen.

What could be added to this experiment to improve the data representation?

A group of scientists wanted to test the effects of Nitra-Grow, a chemical additive that can be given to plants to help them grow. 3 test groups of plants were given all the same time of sunlight, the same type of soil, and the same amount of water. Plant A was given no extra chemicals. Plant B was given 5g of Nitra-Grow. Plant C was given 5g of Ammonia to see if Nitra-Grow worked any better than a basic nitrogen-based household product. The plants are then measured on 5 consecutive days to find their average height (in cm).

On Day 7, what would be plant A’s approximate height?

The table above shows measurements for tumor size growth over time within three different possible treatment methods. Each tumor was first documented at an initial size of 2 inches. Every month each tumor was measured, for a total of five measurements of each tumor.

Based on the table above, which single method is most effective at reducing tumor size in the shortest period of time?

A group of scientists wanted to test the effects of Nitra-Grow, a chemical additive that can be given to plants to help them grow. 3 test groups of plants were given all the same time of sunlight, the same type of soil, and the same amount of water. Plant A was given no extra chemicals. Plant B was given 5g of Nitra-Grow. Plant C was given 5g of Ammonia to see if Nitra-Grow worked any better than a basic nitrogen-based household product. The plants are then measured on 5 consecutive days to find their average height (in cm).

Which plant is the control group?

Understanding the biological features of different bacteria that allow them to grow in unwelcoming environments is necessary to treat and prevent human disease. Modern scientific laboratories, such as those in major hospitals, take blood, urine, and mucus samples from patients and culture them for bacterial growth. During the culturing process, laboratory technicians stain the growing bacteria for a component of their cell wall, the structure that provides shape and rigidity to the bacterium, through a process called Gram staining. Bacteria are typically classified as Gram Positive or Gram Negative, a distinction that is important in selecting the most effective antibiotic for treatment. Gram Positive bacteria appear purple under a microscope, while Gram Negative bacteria appear red. However, some bacteria do not Gram Stain and cannot be seen under a microscope when prepared this way.

Technicians also grow the bacteria on various types of plates containing special growth nutrients to determine which bacteria are causing a specific illness. If a bacterium is able to grow on a selective plate, meaning a plate that contains additional nutrients required for a specific bacterium to grow if it is present in the culture, doctors are able to determine the exact cause of a patient’s illness and prescribe targeted antibiotics to eliminate the infection. Bacteria that commonly cause human illness, their growth requirements, and their appearance on specific growth media are presented below in Table 1.

Table 1

Scientists can take the bacteria cultured on the plate and further analyze their enzymes. Three enzymes—urease, catalase, and beta-lactamase—are important for bacterial survival against the human immune system. Urease is responsible for producing urea, a basic molecule that can counteract the bactericidal (bacteria-killing) activity of stomach acid. Catalase, on the other hand, helps bacteria neutralize toxic substances released from human immune cells, allowing them to survive oxidative stress in high-oxygen areas. Finally, beta-lactamase allows Gram Positive bacteria to break down antibiotics called penicillins. While this ability to break down penicillin and its related antibiotic ampicillin was not initially present, bacteria, especially E. coli, have adapted by developing the new enzyme beta-lactamase that opens the ring responsible for penicillin’s bactericidal activity, rending the antibiotic ineffective. This and other examples of antibiotic resistance are becoming more common and are making treatment of serious human diseases very challenging.

According to information presented in the passage, which bacterium or bacteria is/are not susceptible to penicillin?

A new drug is in its clinical trial phase. The graph below shows the data for participants sleep patterns before medication use and then after using the medication for three months. Series 1 shows the average hours slept a night for each participant prior to medication. Series 2 shows the average hours slept a night for each participant after three months of use. The average hours slept a night was obtained by recording sleep every night for one month, and then finding the average. Patients one through five took a placebo pil, not the actual Moonlight medication. Note: The y-axis is measured in hours slept a night, while the x-axis lists each anonymous patient numerically.

What information would strengthen the experiment?