Biology End Of Course Practice Test #2

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

According to the graph, the cheetah has the highest average fastest speed among the 5 animals. The graph does not provide specific values for the speeds of each animal, but it can be inferred that the elephant is approximately 1/3 as fast as the cheetah based on its position on the graph. The elephant is located significantly lower on the graph compared to the cheetah, indicating a much slower speed. Therefore, the elephant is the species that is approximately 1/3 as fast as the cheetah.

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 wants to determine the effect of temperature on the rate of mold growth. By placing one piece of bread in the refrigerator and another on the countertop, both in closed Petri dishes, the only variable that differs between the two treatments is the temperature. This allows the student to isolate the effect of temperature on mold growth. Placing the bread in an open Petri dish in the same refrigerator or on the countertop would introduce additional variables (such as air circulation) that could confound the results.

Urine has the greatest concentration of hydroxide ions (OH-) because it has a higher pH value (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 when water (H2O) dissociates, a higher pH means a higher concentration of OH- ions. Therefore, urine with a pH of 6.0 has a greater concentration of hydroxide ions compared to rainwater (pH 5.5), tomato juice (pH 2.0), and gastric juice (pH 2.0).

Early autotrophs had an advantage over early heterotrophs because they were able to produce their own food. Autotrophs, such as plants, algae, and some bacteria, are capable of photosynthesis or chemosynthesis, which allows them to convert sunlight or inorganic compounds into energy-rich organic molecules. This ability to produce their own food gave autotrophs a sustainable source of energy, while heterotrophs relied on consuming other organisms for their nutritional needs. By being self-sufficient in their food production, autotrophs had a greater advantage in surviving and thriving in their environment.

The given mRNA sequences differ by only 1 nucleotide, specifically at the 9th position. In Person A, the nucleotide is "A" while in Person B, it is "C". According to the genetic code chart, this change results in the substitution of the amino acid Lysine (Lys) in Person A with Glutamic acid (Glu) in Person B. Therefore, the correct answer is that Lys in Person A is replaced with Glu in Person B.

Both parents must be heterozygous. This is because in order for the offspring to have both black and albino phenotypes, the parents must have both black and albino alleles. Heterozygous individuals have two different alleles for a particular gene, in this case, one allele for black and one allele for albino.

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 members of the same species. If two populations can successfully reproduce and their offspring are capable of reproducing as well, it suggests that they share enough genetic similarity to be considered the same species.

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 a series of electron carriers that transfer electrons from NADH and FADH2 to oxygen. As electrons are passed along the chain, energy is released and used to pump protons across the membrane, creating an electrochemical gradient. This gradient is then used by ATP synthase to produce ATP. Therefore, the electron transport chain is the main source of ATP production in cellular respiration.

Since red-green color blindness is a recessive trait, it can only be expressed in individuals who have two copies of the color blindness allele (Xb). The father (XBY) does not have the color blindness allele, so he cannot pass it on to any of his children. Therefore, a color-blind daughter cannot be born to these parents.

The Golgi apparatus is responsible for processing and packaging cellular materials prior to export. It consists of smooth-sided channels that help in modifying, sorting, and packaging proteins and lipids into vesicles for transport to other parts of the cell or for secretion outside the cell. This activity is unique to the Golgi apparatus and distinguishes it from other organelles mentioned in the options.

In natural selection, certain traits become more or less common in a population over time based on their advantage or disadvantage in the environment. In this example, the fact that giraffe necks vary in length suggests genetic variation within the population. The shorter-necked giraffes being at a disadvantage indicates that their trait is less favorable for survival, which means they are less likely to pass on their genes to the next generation. This process of differential survival and reproduction leads to the gradual increase in the frequency of longer-necked giraffes in the population, illustrating natural selection.

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 the pulse measures the heart rate and the systolic pressure measures the force of blood against the artery walls when the heart beats. Therefore, the increase in both pulse and systolic pressure suggests that more blood is being pumped during exercise compared to rest.

Lydia conducted her investigation to answer the question of how the chemistry of the soil affects the color of hydrangea blossoms. She noticed that the hydrangeas in Container 1 had pink blossoms while those in Container 2 had blue blossoms. Despite receiving the same amount of light and water, she discovered that the soil in Container 1 had a pH of 6.0 while the soil in Container 2 had a pH of 5.0. This suggests that the pH of the soil plays a role in determining the color of the hydrangea blossoms.

The correct answer is "Nature is orderly." This assumption implies that there is a consistent pattern and order in the natural world, including the movement of celestial bodies like the sun and the 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.

The average number of eggs laid per day over the 5 days can be calculated by summing 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 total number of eggs laid over the 5 days is 50 (10 eggs per day * 5 days), and when we divide it by 5, we get the average of 10 eggs laid per day.

The scatterplot shows a positive relationship between height and weight, indicating that as height increases, weight also tends to increase. This means that taller individuals are more likely to be heavier than shorter individuals.

The molecules move into the cell through the channel protein. This is because facilitated diffusion is a passive process that allows molecules to move across the cell membrane with the help of specific proteins. In this case, the channel protein acts as a tunnel or pathway for the molecules to pass through, allowing them to move into the cell. The phospholipid bilayer, on the other hand, does not directly facilitate the movement of molecules in this scenario.

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

Organic compounds are distinguished from inorganic compounds by the presence of carbon. Carbon is a unique element that has the ability to form strong covalent bonds with other elements, including itself, to create a wide variety of complex molecules. This characteristic allows carbon to form the backbone of organic compounds, which are often associated with living organisms. In contrast, inorganic compounds may contain carbon, but they can also exist without it. Therefore, the presence of carbon is the key factor that sets organic compounds apart from inorganic compounds.

This example best illustrates Mendel's law of independent assortment because it shows the inheritance of two different traits (height and flower color) that are not linked or dependent on each other. The fact that tall and white-flowered pea plants are produced in the offspring indicates that the alleles for these traits have segregated independently during the formation of gametes. This supports the principle of independent assortment, which states that different genes for different traits segregate independently of each other during the formation of gametes.

The functional group -NH2, also known as the amino group, is absent from monosaccharides, polysaccharides, fatty acids, and glycerol. Amino acids contain this group, which is responsible for their role in protein synthesis and formation. Monosaccharides are simple sugars and do not have an amino group. Polysaccharides, such as starch and cellulose, are composed of monosaccharides and do not contain an amino group. Fatty acids and glycerol are components of lipids and lack an amino group. Therefore, the correct answer is -NH2.

An individual with albinism has a genotype of homozygous recessive. This means that both of their alleles for the pigmentation gene are recessive, resulting in the absence of pigmentation in their skin. Since pigmented skin is dominant to non-pigmented skin, individuals with albinism must have two copies of the recessive allele.

In order to accurately test the effects of temperature on starch digestion, Edison should begin a second test with 2 g of starch in a test tube and continue with the set of conditions where 1 mL of enzyme suspension is incubated at 37oC for 20 min. This is because the first test was conducted at 25oC for 20 min, so in the second test, Edison needs to change the temperature to see the effects. Additionally, the amount of enzyme suspension should remain the same (1 mL) to maintain consistency between the two tests.

When yeast undergoes respiration, it produces carbon dioxide and ATP. Carbon dioxide is a byproduct of cellular respiration and is released into the environment. ATP, on the other hand, is the energy currency of the cell and is produced during the process of respiration. Therefore, if ethanol is detected in the yeast culture, it suggests that the yeast is undergoing respiration and producing carbon dioxide and ATP as well.

Round eye shape is a recessive trait. This is indicated by the fact that 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. In genetics, a recessive trait is only expressed when an individual has two copies of the recessive allele. Since Jeanine has round eye shape, it means that both of her alleles for eye shape are round, indicating that round eye shape is a recessive trait.

In the absence of light, the green algae Chlorella cannot perform photosynthesis to convert CO2 into glucose. Instead, it undergoes cellular respiration, which is the process of breaking down glucose to release energy. During cellular respiration, CO2 is produced as a byproduct. Therefore, under dark conditions, Chlorella exhibits a negative uptake (release) of CO2 as it is actively undergoing cellular respiration.

To determine whether temperature influences the population size of Paramecium, it is necessary to compare the population growth at different temperatures. By repeating the procedures using 2 flasks and incubating one flask at 15oC and the other at 25oC, the experiment allows for a direct comparison of the population sizes under different temperature conditions. This will provide data to analyze the effect of temperature on the growth of Paramecium and determine if there is a correlation between temperature and population size.

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, and enzymes lower this energy barrier by providing an alternative pathway for the reaction to proceed. This alternative pathway has a lower activation energy, allowing the reaction to happen more easily and quickly. By reducing activation energy, enzymes increase the rate of the reaction without being consumed or permanently altered in the process.

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 through osmosis, causing the cell to swell and gain mass.

In a dihybrid cross, the F1 generation is produced by crossing two heterozygous individuals for two different traits. In this case, the F1 individuals have the genotype AaBb x AaBB. When these individuals are crossed in the F2 generation, the expected ratio of AaBb individuals can be determined using the Punnett square. The possible genotypes of the offspring are AaBB, AaBb, AABb, and AABb. Out of these four possible genotypes, only one is AaBb. Therefore, the expected ratio of AaBb individuals in the F2 generation is 1 out of 4, which is equivalent to 4/16.

The genotype for Individual 1 in the diagram is Aa. This is because the disorder is determined by 2 alleles at 1 locus, meaning that there are two possible forms of the gene for this disorder. Individual 1 has a combination of both alleles, which is represented by the genotype Aa.

The scientist is studying the interactions between barnyard grass, other weeds, rice, and insects. These organisms are all living together in a specific area and are interacting with each other. This indicates that they make up a community, which is a group of different species living in the same area and interacting with each other.

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 smaller unit of measure compared to kilogram and kilometer, and it is commonly used to measure small masses. Since the mass of the fungus is expected to be relatively small, milligram would provide a more precise measurement for Chan's experiment. Millimeter, on the other hand, is a unit of measure for length and not mass, so it is not appropriate in this context.

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 data recorded in the graphs, where the number of bacterial colonies is consistently higher for the 30-day old culture compared to the new culture, regardless of the strain being used.

In this cricket population, there is a clear shift towards the trait of flat wings over curved wings. This indicates that there is a directional selection occurring, where one extreme of the trait (flat wings) is favored over the other extreme (curved wings). The selection pressure is caused by the parasitic flies, as they target and kill the male crickets with curved wings who produce mating songs. The flat-winged crickets, on the other hand, are able to mate with females and avoid detection by the flies, allowing them to survive and pass on their genes.

The fossil record indicates that the size of horses increased over time, suggesting that larger horses had a higher chance of survival and reproduction. This implies that larger horses produced a slightly greater number of surviving offspring, leading to an overall increase in the size of the horse population. This explanation is supported by the principles of natural selection, where individuals with advantageous traits have a better chance of passing on those traits to future generations.

Assigning the subjects to groups at random is important in order to ensure scientifically valid results because random assignment helps to eliminate potential biases and ensure that the groups are comparable. This helps to ensure that any observed differences between the groups can be attributed to the medication and not to other factors. Random assignment helps to increase the internal validity of the study and strengthens the ability to make causal inferences.

A scientific theory is the best definition of a scientific theory because it provides an explanation of how and why a natural phenomenon behaves the way it does. It goes beyond a simple description of a relationship in nature and is not merely a speculation or guess. Additionally, a scientific theory is not an unproven fact, as it is based on extensive research, evidence, and experimentation.

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 comparison among different feed mixtures while controlling for other variables by using similar groups of cows. By measuring weight gain, scientists can directly assess the impact of each feed mixture on lean muscle mass in the cows.

When the pH of the stomach increases due to the intake of antacids, it causes the active site of pepsin to change shape. This change in shape makes it difficult for pepsin to bind with and break down proteins effectively. As a result, the efficiency of protein digestion is reduced.

Papain is a protease enzyme, which means it helps in breaking down proteins. Therefore, papain helps digest proteins.

DNA and RNA both contain purine bases, which are adenine (A) and guanine (G). These purine bases are responsible for the genetic information and coding in both DNA and RNA molecules. They play a crucial role in the formation of the complementary base pairs, where adenine pairs with thymine (in DNA) or uracil (in RNA), and guanine pairs with cytosine. Therefore, the similarity in the structure of purine bases is a significant characteristic shared by DNA and RNA.

During aerobic cellular respiration, ATP molecules form in the mitochondrial matrix and inner mitochondrial membrane only. This is because the process of aerobic respiration occurs in the mitochondria, specifically in the inner membrane and matrix. The inner mitochondrial membrane contains the electron transport chain, which plays a crucial role in generating ATP through oxidative phosphorylation. The matrix, on the other hand, is where the Krebs cycle occurs, producing high-energy molecules that are used in the electron transport chain to generate ATP. Therefore, ATP synthesis primarily occurs in the mitochondrial matrix and inner mitochondrial membrane.

Cyclohexamide acts on the ribosome. The ribosome is responsible for protein synthesis in cells. By adding cyclohexamide to the cells, Naomi is able to identify short incomplete segments of proteins. This suggests that cyclohexamide is inhibiting the ribosome's ability to complete protein synthesis, resulting in the formation of incomplete protein segments.

The presence of chloroplast indicates that cells are photosynthetic bacteria, as chloroplasts are the organelles responsible for photosynthesis. Therefore, the absence of chloroplasts suggests that the cells are not photosynthetic bacteria.

When the pH in a stomach increases from 2 to 4, it means that the stomach becomes less acidic. pH is a logarithmic scale that measures the concentration of hydrogen ions (H+) in a solution. As the pH increases by 2 units, it indicates a decrease in the hydrogen ion concentration by a factor of 100. This is because each unit on the pH scale represents a tenfold change in the concentration of hydrogen ions. Therefore, when the pH increases from 2 to 4, the hydrogen ion concentration decreases by a factor of 100.

ATP (adenosine triphosphate) is the molecule that provides energy for muscle contraction. When ATP is hydrolyzed (broken down) into ADP (adenosine diphosphate) and inorganic phosphate, energy is released. This energy is used by muscle cells to power the contraction process. Glucose is a source of energy for ATP production, but it is not directly involved in muscle contraction. Lactic acid and oxygen are not directly involved in providing energy for muscle contraction.

The aerobic and anaerobic pathways of cellular respiration require pyruvate and NADH as products of glycolysis. Pyruvate is the end product of glycolysis and is further broken down in the presence of oxygen during aerobic respiration. NADH is an electron carrier that is produced during glycolysis and is used in the electron transport chain to generate ATP. Therefore, both pyruvate and NADH are essential for the continuation of cellular respiration in both aerobic and anaerobic conditions.

The regulation of gene expression leads to cell specialization by methylation of some regions of DNA preventing transcription. Methylation is a process where methyl groups are added to specific regions of DNA, which can inhibit the binding of transcription factors and RNA polymerase to the DNA, thus preventing the transcription of genes in those regions. This selective methylation allows different genes to be expressed in different cell types, leading to the specialization and differentiation of cells in multicellular organisms.