EOC Practice Test #1

Prophase (chromosomes condense & nuclear membrane disappears)
Metaphase (chromosomes line up in the MIDDLE)
Anaphase (chromosomes are pulled APART)
Telophase (2 nuclear membranes form & cytokinesis occurs

The average number of eggs laid per day over the 5 days can be calculated by adding up the total number of eggs laid over the 5 days and then dividing it by 5 (the number of days). In this case, the researcher recorded the number of eggs laid per day for 5 days and found that the total number of eggs laid was 50. Therefore, the average number of eggs laid per day is 10.

Urine has the greatest concentration of hydroxide ions (OH-) because it has a higher pH value of 6.0 compared to the other solutions. pH is a measure of the concentration of hydrogen ions (H+), and a higher pH indicates a lower concentration of H+ ions. Since hydroxide ions (OH-) are formed by the reaction of water with H+ ions, a higher pH means a lower concentration of H+ ions and therefore a higher concentration of OH- ions. Therefore, urine with a pH of 6.0 has a greater concentration of hydroxide ions compared to rainwater, tomato juice, and gastric juice with lower pH values.

The Golgi apparatus is responsible for processing and packaging cellular materials prior to export. It consists of smooth-sided channels or cisternae that modify, sort, and package proteins and lipids into vesicles for transport to their final destinations within or outside the cell. This activity is distinct from the other options provided, which are not directly related to the Golgi apparatus.

The given answer correctly states that the difference in the mRNA sequences between Person A and Person B results in a replacement of Lysine (Lys) with Glutamic acid (Glu) in the resulting protein. This is because the codon for Lysine (AAA) in Person A's mRNA sequence is changed to the codon for Glutamic acid (GAG) in Person B's mRNA sequence due to the difference in a single nucleotide. Therefore, the amino acid sequence of the resulting protein is affected, leading to the replacement of Lysine with Glutamic acid.

An individual with albinism has a genotype of homozygous recessive. This means that both alleles for the pigmentation gene are recessive, resulting in the absence of pigment in the skin.

Early autotrophs had an advantage over early heterotrophs because they were capable of producing their own food through photosynthesis or chemosynthesis. This ability allowed them to obtain energy directly from the environment, without relying on consuming other organisms. In contrast, early heterotrophs had to rely on consuming other organisms for their energy needs. By being able to produce their own food, autotrophs had a more reliable and sustainable source of energy, which gave them a competitive edge in their environment.

The example that best illustrates the process of natural selection is when giraffe necks varied in length, and the shorter-necked giraffes were at a disadvantage. This scenario demonstrates the key elements of natural selection, where there is variation in a population and certain traits provide a disadvantage or advantage in survival and reproduction. In this case, the shorter-necked giraffes have a harder time reaching food, which reduces their chances of survival and passing on their genes. As a result, over time, the population will have a higher proportion of giraffes with longer necks, as they are better adapted to their environment.

The statement "They produce fertile offspring" most likely indicates that the two populations of animals are the same species. This is because the ability to produce fertile offspring is a key characteristic of a species. If two populations can successfully mate and produce offspring that can also reproduce, it suggests that they share enough genetic similarity to be considered the same species. The other statements, such as inhabiting the same area, having a similar appearance, or consuming the same type of diet, do not necessarily indicate that the populations are the same species.

A scientific theory is the best definition because it provides an explanation for how and why a natural phenomenon behaves the way it does. It goes beyond just describing an invariable relationship or making a speculation or guess. It is also different from an unproven fact, as a scientific theory is supported by evidence and has undergone rigorous testing and scrutiny.

The key factor that distinguishes organic compounds from inorganic compounds is the presence of carbon. Carbon is the fundamental element that is found in all organic compounds, while inorganic compounds do not contain carbon. Carbon forms the backbone of organic molecules, allowing for the vast diversity and complexity of organic compounds. This characteristic of carbon allows organic compounds to exhibit unique properties and participate in various chemical reactions that are essential for life processes.

Papain is an enzyme found in papaya that belongs to the protease family. Proteases are responsible for breaking down proteins into smaller peptides and amino acids. Therefore, papain helps in the digestion of proteins.

The most likely explanation for the cell's gain in mass is that the solution is hypotonic to the cell. In a hypotonic solution, the concentration of solutes is lower outside the cell compared to inside the cell. As a result, water moves into the cell by osmosis, causing it to swell and gain mass.

Based on the graph, the elephant is approximately 1/3 as fast as the cheetah. This can be determined by comparing the speeds of the animals on the graph. The graph shows that the cheetah has the highest speed, and the elephant's speed is significantly lower, indicating that it is approximately 1/3 as fast as the cheetah.

Metaphase I = homologous chromosomes are pulled to the middle of the cell

The molecules move into the cell through the channel protein. The diagram shows a cell membrane composed of a phospholipid bilayer with a channel protein. Facilitated diffusion is a process that allows molecules to pass through a cell membrane with the help of specific channel proteins. Therefore, the molecules in this case will move into the cell through the channel protein.

In this cricket population, the number of males with flat wings has increased over generations. This change in the population is due to the selective pressure imposed by the parasitic flies. The flies detect and kill male crickets that produce mating songs by rubbing their curved wings together. As a result, the males with flat wings, who do not sing, have a higher survival rate and are able to mate with females. This leads to a directional selection, where the population is shifting towards a specific trait (flat wings) that provides a selective advantage in the presence of the parasitic flies.

The correct answer is "How does the chemistry of the soil affect the color of hydrangea blossoms?" because Lydia conducted her investigation to understand the relationship between the pH of the soil and the color of the hydrangea blossoms. She noticed that hydrangeas in Container 1 with a pH of 6.0 had pink blossoms, while hydrangeas in Container 2 with a pH of 5.0 had blue blossoms. This suggests that the acidity of the soil, determined by its pH, affects the availability of certain pigments in the plant, resulting in different flower colors.

The electron transport chain is responsible for generating the majority of ATP during cellular respiration. This process occurs in the inner mitochondrial membrane and involves the transfer of electrons from electron carriers to oxygen. As the electrons pass through a series of protein complexes, energy is released and used to pump protons across the membrane. This creates an electrochemical gradient that drives the synthesis of ATP by ATP synthase. Overall, the electron transport chain is the final step in cellular respiration and produces the most ATP compared to glycolysis, fermentation, and the Krebs cycle.

The scientist is studying the interactions between barnyard grass, other weeds, rice, and insects. These organisms are all living in the same area and are interacting with each other. Therefore, the correct answer is "Community," which refers to a group of different species living and interacting in the same location.

This example best illustrates Mendel's law of independent assortment because it shows the inheritance of two different traits (tallness and flower color) that are independently inherited. The fact that the offspring include tall white-flowered pea plants indicates that the genes for these traits are segregating independently, as predicted by Mendel's law.

In a dihybrid cross, the genotype of the F1 individuals is AaBb x AaBB. When these individuals are crossed, the possible genotypes in the F2 generation are AABb, AaBb, AABb, and AaBB. Out of these four possible genotypes, only one genotype (AaBb) has the combination of alleles AaBb. Therefore, the expected ratio of AaBb individuals in the F2 generation is 1 out of 4, which is equivalent to 4/16.

The most accurate conclusion about the growth rate of the bacteria is that the 30-day old culture grows faster regardless of the strain. This can be inferred from the information provided in the question, where in both experiments, when Strain Y is the 30-day old culture, it consistently shows a higher number of bacterial colonies compared to Strain X. This indicates that the 30-day old culture has a faster growth rate, regardless of the strain being used.

Round eye shape is a recessive trait because Jeanine inherited 2 alleles for round eye shape and has round eye shape, while her brother inherited 1 allele for round eye shape and 1 allele for almond eye shape and has almond eye shape. This indicates that the almond eye shape allele is dominant over the round eye shape allele, and round eye shape is only expressed when an individual has two copies of the recessive allele.

Testing 5 similar groups of cows with 5 different feed mixtures and measuring their weight gain at the end of a 6-week trial would provide scientists with the best data for investigating which type of feed yields the greatest gain in lean muscle mass in cattle. This design allows for a direct comparison between different feed mixtures, as each group of cows is exposed to a different feed. By using similar groups of cows, any variations in weight gain can be attributed to the different feed mixtures rather than other factors. This design also allows for a larger sample size, increasing the statistical power of the study.

The scatterplot shows that as height increases, weight also tends to increase. This suggests a positive relationship between height and weight, indicating that taller individuals tend to be heavier. However, it is important to note that this conclusion is based on the data collected and may not apply universally to all individuals in the population.

The basic assumption of science that Ella is operating under is that nature is orderly. This means that there are consistent patterns and laws that govern the natural world, including the movement of celestial bodies like the sun and moon. Ella's statement about the sun setting at 6:30 p.m. and there being a full moon on Thursday night suggests that she believes in the predictability and regularity of natural phenomena.

Both parents must be heterozygous for the trait because they produced both black and albino offspring. If both parents were homozygous for black fur, then all of their offspring would also have black fur. However, since they produced albino offspring, it indicates that at least one of the parents carries the recessive allele for albinism. Therefore, both parents must be heterozygous for the trait.

The experiment's results support Paul's statement because they show that exercise increases both the pulse and the systolic pressure. This indicates that the heart is pumping more blood during exercise, as a higher pulse rate and systolic pressure are both indicators of increased blood flow.

When the pH in the stomach increases from 2 to 4, it means that the solution becomes less acidic. pH is a logarithmic scale, so each unit represents a tenfold difference in acidity. Therefore, an increase of 2 units in pH corresponds to a decrease in hydrogen ion concentration by a factor of 100.

The question is asking for the genotype of Individual 1 in the diagram. The diagram is not provided, so we cannot determine the specific alleles present in Individual 1. However, we know that Alkaptonuria is determined by 2 alleles at 1 locus. Therefore, the genotype for Individual 1 could be either AA or Aa, as both of these genotypes have the potential to carry the alleles responsible for Alkaptonuria.

The fossil record indicates that the size of horses increased over time. This suggests that larger horses were more successful in reproducing and passing on their genes to the next generation. As a result, they produced a slightly greater number of surviving offspring compared to smaller horses. Over many generations, this led to an overall increase in the size of horses.

The best comparison for this experiment would be placing another piece of bread in a closed Petri dish on the countertop. This is because the student is testing the effect of temperature on mold growth, so it is important to have a control group that is exposed to the same conditions as the experimental group (bread in the refrigerator), but without the variable being tested (temperature). By placing the bread in a closed Petri dish on the countertop, it ensures that both the experimental and control groups are in the same environment, but only the experimental group is exposed to the colder temperature in the refrigerator.

To determine whether temperature influences the population size of Paramecium, it is necessary to compare the growth of Paramecium at different temperatures. By repeating the procedures described using 2 flasks and incubating one flask at 15oC and the other at 25oC, it allows for a direct comparison of the population sizes under different temperature conditions. This experimental setup controls for other variables and allows for a clear evaluation of the impact of temperature on the population size of Paramecium.

In dark conditions, Chlorella cannot perform photosynthesis due to the absence of light. As a result, it relies on cellular respiration to generate energy. During cellular respiration, CO2 is released as a byproduct. Therefore, under dark conditions, there is a negative uptake (release) of CO2 because Chlorella is actively undergoing cellular respiration.

To accurately test the effects of temperature on starch digestion, Edison should begin a second test with the same amount of starch (2g) in a test tube. Since the first test was incubated at 25oC for 20 minutes, the second test should have a different temperature condition to observe the effects. Among the given options, the only one that meets this requirement is "1 mL of enzyme suspension incubated at 37oC for 20 min". This will allow Edison to compare the effects of different temperatures on starch digestion by keeping the enzyme suspension amount constant and changing only the temperature.

During yeast respiration, glucose is broken down in the absence of oxygen, leading to the production of ethanol, carbon dioxide, and ATP. The presence of ethanol in the yeast culture indicates that glucose fermentation has occurred. Carbon dioxide is also produced as a byproduct of this process. ATP is generated through the breakdown of glucose and is used as a source of energy by the yeast cells. Therefore, the yeast culture contains carbon dioxide and ATP.

not-available-via-ai

Enzymes speed up chemical reactions by reducing the activation energy required for the reaction to occur. Activation energy is the energy needed to start a chemical reaction. Enzymes lower this energy barrier by binding to the reactant molecules and bringing them closer together, making it easier for them to collide and react. This allows the reaction to proceed more rapidly, ultimately increasing the rate of the chemical reaction.

When the pH of the stomach increases due to the use of antacids, the active site of pepsin, which is responsible for binding and breaking down proteins, undergoes a conformational change. This change in shape of the active site makes it less effective in binding to and digesting proteins, thus reducing the efficiency of protein digestion.

The presence of chloroplast indicates that cells are photosynthetic bacteria. Chloroplasts are organelles found in plant cells and some bacteria that are responsible for photosynthesis, the process by which plants convert sunlight into energy. Therefore, if cells do not have chloroplasts, it indicates that they are not capable of photosynthesis and are not photosynthetic bacteria.

The most appropriate unit of measure for Chan to use in determining the mass of fungus growing on a nutrient agar plate over an 8 hr period would be milligram. Milligram is a unit of mass that is commonly used for small measurements, making it suitable for measuring the mass of the fungus. Kilogram and kilometer are units of measure for distance and larger masses respectively, while millimeter is a unit of measure for length.

Cyclohexamide acts on the ribosome. Ribosomes are responsible for protein synthesis in cells. By adding cyclohexamide, which is an inhibitor of protein synthesis, Naomi is able to observe the formation of short incomplete segments of proteins in the cells. This suggests that the ribosomes are being affected by the cyclohexamide, leading to the production of incomplete proteins.

The functional group -NH2, also known as the amino group, is absent from monosaccharides, polysaccharides, fatty acids, and glycerol. Monosaccharides are simple sugars and do not contain an amino group. Polysaccharides are made up of multiple sugar units and also lack an amino group. Fatty acids, which are the building blocks of lipids, and glycerol, a component of triglycerides, do not have an amino group. The absence of -NH2 in these molecules distinguishes them from amino acids, which contain this functional group.

DNA and RNA both contain purine bases, which are a type of nitrogenous base. Purine bases include adenine (A) and guanine (G). These bases are responsible for the genetic information carried by DNA and RNA. Therefore, the structure of purine bases is similar in both DNA and RNA.

Assigning the subjects to groups at random is important in order to ensure scientifically valid results because it helps to eliminate bias and ensure that the two groups are comparable. Random assignment helps to distribute potential confounding factors evenly across the groups, making it more likely that any differences observed between the groups are due to the medication and not other factors. This increases the internal validity of the study and allows for more accurate conclusions to be drawn.

Glucose is the correct answer because during the process of muscle contraction, glucose is broken down through a series of chemical reactions in a process called glycolysis. This breakdown of glucose releases energy in the form of ATP (adenosine triphosphate), which is used as the primary source of energy for muscle contraction. Therefore, the hydrolysis of glucose provides the necessary energy for muscle contraction.

During aerobic cellular respiration, ATP molecules form in the mitochondrial matrix and inner mitochondrial membrane. This is because the mitochondrial matrix is where the Krebs cycle occurs, which produces high-energy molecules that are used to generate ATP through oxidative phosphorylation in the inner mitochondrial membrane. The cytoplasm does not directly produce ATP molecules during aerobic cellular respiration. The outer mitochondrial membrane is not directly involved in ATP production, as its main function is to separate the mitochondria from the rest of the cell.

During glycolysis, glucose is broken down into pyruvate molecules. These pyruvate molecules are then used as substrates in both the aerobic and anaerobic pathways of cellular respiration. NADH is also produced during glycolysis as a result of the oxidation of NADH to NAD+. Both pyruvate and NADH are essential for the subsequent steps of cellular respiration to occur, making them the required products of glycolysis for both aerobic and anaerobic respiration. ATP is also produced during glycolysis, but it is not specifically required for the pathways to proceed.

The regulation of gene expression leads to cell specialization because methylation of certain regions of DNA prevents transcription. Methylation is a process where methyl groups are added to the DNA molecule, which can inhibit the binding of transcription factors and RNA polymerase to the DNA, thus preventing the transcription of specific genes. This allows cells to selectively activate or deactivate certain genes, leading to the development of specialized cell types with different functions and characteristics.