Biology B - Practice Final Exam

Meiosis is the process that produces sex cells, such as sperm and eggs, through the division of cells. This process involves two rounds of division, resulting in four daughter cells with half the number of chromosomes as the parent cell. On the other hand, mitosis is the process that produces body cells, or somatic cells, through the division of cells. This process involves one round of division, resulting in two daughter cells that are genetically identical to the parent cell. Therefore, the correct answer is Meiosis, Mitosis.

A mutation refers to a change in the DNA sequence. It can occur due to various factors, such as errors during DNA replication or exposure to mutagens. Mutations can have different effects on living things, ranging from being neutral or having no noticeable impact to being harmful or beneficial. Therefore, it is not accurate to say that mutations are always harmful to living things.

A population of organisms with a wide variation of traits will be more likely to survive a drastic change in the environment because they have a higher chance of possessing traits that are advantageous in the new conditions. This diversity allows for some individuals to have traits that enable them to adapt and thrive in the changed environment, increasing the overall survival rate of the population.

The fusion of a sperm cell and an egg cell is known as fertilization. This process results in the formation of a zygote, which is the earliest stage of development of a new individual. The zygote contains the genetic material from both the sperm and egg, and it will undergo cell division to form an embryo. A polar body is a small non-functional cell that is produced during the process of oogenesis, and a gonad refers to the reproductive organ that produces gametes (sperm or eggs).

Homeostasis refers to the ability of an organism to maintain a stable internal environment despite external changes. Sweating is a mechanism by which the body regulates its temperature. When the body gets too hot, sweat glands are activated to produce sweat, which evaporates from the skin and cools the body down. This process helps maintain a constant body temperature, which is a key aspect of homeostasis. Genetic diversity, evolution, and recombination are not relevant to the given scenario.

Omnivores are organisms that have the ability to consume both plants and animals as part of their diet. This means that they have the flexibility to obtain nutrients and energy from a variety of sources, including both producers (plants) and other consumers (animals). Unlike herbivores that only eat plants or carnivores that only eat animals, omnivores have a wider range of food options available to them, allowing them to adapt to different environments and obtain a more diverse diet.

Graph A shows human population growth because it displays an upward trend over time. The y-axis represents the population size, while the x-axis represents time. As time progresses, the population steadily increases, indicating growth. On the other hand, Graph B may represent a different variable or unrelated data, as it does not show a clear pattern of population growth. Therefore, Graph A is the correct answer.

When genes are located on the X or Y chromosomes, the traits are called sex-linked. This means that the inheritance of these traits is determined by the sex of the individual. In humans, for example, traits such as color blindness and hemophilia are sex-linked and are more commonly seen in males because they only have one X chromosome. Females, on the other hand, have two X chromosomes, so they have a higher chance of being carriers of sex-linked traits without showing the phenotype.

Transcription is the process by which genetic information from DNA is copied into RNA molecules. This process occurs in the nucleus of a cell. The nucleus is the compartment within a cell that contains the DNA. It is where the DNA is transcribed into RNA by the enzyme RNA polymerase. Therefore, the statement "Transcription happens in the nucleus of a cell" is true.

The correct answer is GG. In genetics, homozygous dominant refers to an individual having two copies of the same dominant allele for a particular trait. In this case, the allele combination GG represents homozygous dominant because both alleles are uppercase and represent the dominant form of the gene. The other options, gg, Gg, and GY, do not represent homozygous dominant because they either have lowercase alleles (gg), a combination of uppercase and lowercase alleles (Gg), or include a different allele (GY).

The correct answer is "shows the position of an organism in an ecosystem as to how they receive energy." This is because a trophic level is a hierarchical level in an ecosystem that represents the position of an organism in the food chain and indicates how it obtains energy. Organisms at lower trophic levels, such as producers, obtain energy directly from the sun or other inorganic sources, while organisms at higher trophic levels, such as carnivores, obtain energy by consuming other organisms.

If a local farmer poisons the rodents in the area, killing most of the mice, shrews, and rabbits, the homeostasis of the area would change by causing a decrease in snake populations. Since snakes primarily feed on rodents, a decline in their prey population would result in a decrease in snake numbers. This disruption in the predator-prey relationship would lead to a decrease in snake populations, affecting the balance of the ecosystem.

The likely cause for the beak variations in finch populations is natural selection. Natural selection is the process by which organisms that are better adapted to their environment are more likely to survive and reproduce, passing on their advantageous traits to future generations. In the case of the finches on the Galapagos Islands, the variations in beak size and shape are likely a result of different food sources available on the islands. Finches with beaks that are better suited for a particular type of food are more likely to survive and reproduce, leading to the diversification of beak characteristics in the population.

The introduction of an invasive species like the zebra mussel affects the environment by competing for resources with local populations. This competition can lead to a decrease in the availability of resources for native species, causing disruptions in the ecosystem. The zebra mussels can outcompete native species for food and habitat, potentially leading to a decline in their population. This can have cascading effects on other species that depend on the native species for food or other interactions within the ecosystem.

The greenhouse effect refers to the process in which certain gases in the Earth's atmosphere trap heat from the sun, causing the Earth's temperature to increase. This is the correct answer because it accurately describes the phenomenon of the greenhouse effect and its impact on the Earth's temperature.

Bacteria play a crucial role in the nitrogen cycle by converting unusable nitrogen into a form that can be utilized by living organisms. This process, known as nitrogen fixation, involves certain bacteria converting atmospheric nitrogen into ammonia or nitrate. These nitrogen compounds can then be taken up by plants and other organisms to synthesize proteins and other essential molecules. Without the action of bacteria, the nitrogen present in the atmosphere would be largely inaccessible to living things, leading to a shortage of this vital nutrient in ecosystems.

Translation is the process by which mRNA is read and used as a template to synthesize proteins. During translation, the ribosome binds to the mRNA molecule and reads the sequence of nucleotides, using it to assemble the corresponding amino acids into a protein chain. This process occurs in the cytoplasm of the cell and is essential for the expression of genetic information and the production of functional proteins. Transcription, on the other hand, refers to the synthesis of mRNA from DNA. Crossing over and recombination are processes that occur during meiosis and involve the exchange of genetic material between homologous chromosomes.

Photosynthesis is the process by which plants and some other organisms convert light energy into chemical energy in the form of glucose. During this process, carbon dioxide is taken in from the environment and oxygen is released. Cell respiration, on the other hand, is the process by which cells break down glucose to release energy. During this process, carbon dioxide is released into the environment. Therefore, both photosynthesis and cell respiration are processes that move carbon in and out of the environment.

Autotrophs, such as plants and algae, use the process of photosynthesis to convert carbon dioxide from the environment into glucose and oxygen. This process decreases the amount of carbon dioxide in the environment, as carbon is incorporated into glucose and oxygen is released. Therefore, autotrophs using the process of photosynthesis will decrease the amount of carbon in the environment.

The given mutation involves a change in a single nucleotide, where the nucleotide "T" in the normal DNA sequence is replaced by "G" in the mutated DNA sequence. This type of mutation is known as a substitution.

A haploid cell is a cell that contains only one set of chromosomes, as opposed to the usual two sets found in most cells. Sperm cells are an example of haploid cells because they contain only half the number of chromosomes found in other cells of the body. This is important for sexual reproduction, as when a sperm cell fuses with an egg cell during fertilization, the resulting zygote will have the correct number of chromosomes. Liver cells, cheek cells, and zygotes are not examples of haploid cells as they contain the usual two sets of chromosomes.

Limiting factors are any factors that restrict the growth of a population. These factors can include availability of resources, competition for resources, predation, disease, and environmental conditions. They act as constraints on population growth, preventing the population from reaching its maximum potential size. Density-dependent factors, on the other hand, are limiting factors that become more significant as the population density increases. Equilibrium factors and growth factors are not accurate terms to describe factors that restrict population growth.

The cougar is classified as a secondary consumer because it feeds on herbivores, which are primary consumers. Secondary consumers obtain their energy by consuming primary consumers, and they are positioned one level higher in the food chain.

When a cat with black whiskers (BB) is bred to a cat with white whiskers (bb), the possible genotypes of the offspring are Bb and Bb. This is because the black whiskers (B) are dominant over the white whiskers (b), so even if one parent has the dominant allele and the other has the recessive allele, the offspring will still have the dominant trait. Therefore, the probability of the offspring having the genotype Bb is 100%.

Transcription is the process by which DNA is copied into mRNA. During transcription, the DNA sequence is transcribed into a complementary mRNA sequence by RNA polymerase. This mRNA molecule can then be used as a template for protein synthesis during translation. Therefore, transcription is the correct term for the process of copying DNA into mRNA.

When a cat with black whiskers (BB) is bred to a cat with white whiskers (bb), the offspring will inherit one allele from each parent. Since black whiskers (B) is dominant over white whiskers (b), the offspring will have the genotype Bb. The phenotype of the offspring will be black whiskered, as the dominant allele B determines the expression of black whiskers.

Polygenic traits are controlled by multiple genes. This means that the phenotype of these traits is influenced by the interaction of multiple genes, rather than a single gene. For example, traits like skin color and height are determined by the combined effects of several genes. Each gene contributes a small amount to the overall phenotype, resulting in a wide range of variation in these traits within a population. This is why these traits often show a continuous distribution rather than distinct categories, as seen in Mendelian traits.

Graph B shows a population meeting its carrying capacity. In this graph, the population initially increases rapidly, but eventually levels off and stabilizes at a certain point. This indicates that the population has reached its maximum sustainable size, or carrying capacity, where the available resources can support the population without further growth.

The given answer, "building muscles with weights and having muscular offspring," is not an example of natural selection because natural selection refers to the process by which certain traits become more or less common in a population over time due to their impact on survival and reproduction. In this case, building muscles with weights and having muscular offspring is not a result of genetic variation or adaptation to the environment, but rather a result of intentional human intervention through exercise and training.

Using fertilizer is the correct answer because fertilizers contain nitrogen compounds that are added to the soil to provide essential nutrients for plant growth. When these fertilizers are applied to crops or gardens, they release nitrogen into the environment. This excess nitrogen can leach into water bodies, leading to water pollution and harmful effects on aquatic ecosystems. Additionally, nitrogen from fertilizers can also be converted into nitrogen oxides, contributing to air pollution and the formation of smog. Therefore, the use of fertilizers is a significant human activity that increases the amount of nitrogen in the environment.

Mutations that do not affect the protein being assembled are called silent mutations. These mutations occur when there is a change in the DNA sequence, but it does not result in a change in the amino acid sequence of the protein. Silent mutations are often caused by substitutions in the DNA sequence where the new codon still codes for the same amino acid as the original codon. Therefore, these mutations have no effect on the final protein product and are considered neutral in terms of their impact on the organism.

Traits acquired over a lifetime are not a reason that populations will evolve because evolution occurs through changes in the genetic makeup of a population over generations, not within an individual's lifetime. Traits acquired during an individual's lifetime, such as skills or knowledge, are not passed on to offspring and therefore do not contribute to the genetic variation necessary for evolution. Evolution is driven by factors like mutation of DNA, genetic drift, and natural selection, which affect the genetic composition of populations over time.

If the color of seahorses is incompletely dominant, it means that neither the red color nor the white color is completely dominant over the other. When a red seahorse is crossed with a white seahorse, the offspring will have a blending of both colors, resulting in pink seahorses. This is because neither color is able to fully overpower the other, leading to a mixture of the two colors in the offspring.

The given answer "All of the above" is correct because homologous structures are evidence of common ancestry and they are similar in structure but have different functions. This means that organisms with homologous structures share a common ancestor and have evolved to have similar body parts with different functions. Therefore, all of the statements provided are true.

The complementary strand of DNA would have the same sequence as the original strand, but with the nucleotides paired in a complementary way. In DNA, adenine (A) pairs with thymine (T) and cytosine (C) pairs with guanine (G). Therefore, the complementary strand would be T A A G G G C T T A G G G.

RNA nucleotides are composed of four different bases: adenine (A), uracil (U), cytosine (C), and guanine (G). The base pairing in RNA follows a specific pattern: adenine (A) always pairs with uracil (U), and cytosine (C) always pairs with guanine (G). Therefore, the correct base pairs for RNA nucleotides are A-U and C-G.

An ecosystem is defined as the biotic and abiotic factors interacting in an area. This means that it includes both living organisms (biotic factors) and non-living components such as temperature, sunlight, soil, and water (abiotic factors) that interact and influence each other within a specific geographical area. This definition highlights the interconnectedness and interdependence of all the components within an ecosystem, emphasizing the importance of studying and understanding these interactions for ecological research and conservation efforts.

Peptide bonds are the type of bonds that join amino acids together to form proteins. These bonds are formed through a dehydration synthesis reaction, where the carboxyl group of one amino acid reacts with the amino group of another amino acid, resulting in the formation of a peptide bond. This bond is essential for the structural integrity and function of proteins.

Inherited mutations like PKU and sickle cell anemia are passed on through sexual reproduction because these mutations occur in the DNA of reproductive cells (sperm and egg). During sexual reproduction, the sperm and egg combine to form a new individual with a combination of genetic material from both parents. This means that if one or both parents carry the mutated gene, there is a chance that the offspring will inherit the mutation. Mitosis of body cells, building of proteins, and incomplete separation of chromosomes do not involve the transfer of genetic material from one generation to the next, so they are not responsible for passing on inherited mutations.

Exponential growth indicates that a population is able to continuously increase in size without any limitations or constraints. This suggests that the population has access to abundant resources that can support its growth and reproduction. The availability of unlimited resources allows individuals to thrive and reproduce at a rapid rate, leading to exponential population growth.

As an embryo develops, cells undergo a process called differentiation, where they become specialized and take on specific functions. This is essential for the formation of different tissues and organs in the body. Mitosis refers to the division of cells to produce two identical daughter cells, while meiosis is a type of cell division that occurs in reproductive cells to produce gametes. Cleavage refers to the rapid cell division that occurs during the early stages of embryonic development. Therefore, differentiation is the correct answer as it accurately describes the process of cell specialization during embryo development.

Photosynthesis and cellular respiration are the processes that transfer both matter and energy through an ecosystem. Photosynthesis is the process by which plants convert sunlight, water, and carbon dioxide into glucose and oxygen, thereby transferring energy and matter from the environment into the ecosystem. Cellular respiration, on the other hand, is the process by which organisms break down glucose and oxygen to release energy and produce carbon dioxide and water as waste products, thus transferring energy and matter within the ecosystem. Meiosis and natural selection do not directly involve the transfer of matter and energy through an ecosystem.

Global warming is the increase in Earth's average temperature due to the buildup of greenhouse gases in the atmosphere. This leads to the melting of polar ice caps and rising sea levels, as the increased temperature causes the ice to melt and the water to expand. Global warming also causes unusual climate changes, such as more frequent and intense heatwaves, storms, and droughts, which can destroy ecosystems. Loss of land mass can occur due to coastal erosion and flooding caused by rising sea levels. However, global warming does not lead to a decrease in overall temperatures on Earth.

The correct answer is population. A population refers to a group of organisms of the same species that live in the same area and can interbreed. It represents the number of individuals of a species in a given location and is a fundamental unit in ecology. A community refers to the interaction of different species in a particular area, an ecosystem includes the community and its physical environment, and a habitat is the specific place where an organism lives. Therefore, population best describes the concept of organisms of the same species in an area.

The correct tRNA sequence for the given mRNA sequence is UAC AUU GGC UUG. The tRNA sequence is complementary to the mRNA sequence, with each codon on the mRNA being matched with its corresponding anticodon on the tRNA. The tRNA carries the amino acids that will be used to build the protein during translation.

Oxygen, carbon dioxide, and glucose are molecules that can be used by some types of living organisms. Oxygen is essential for cellular respiration, which is the process by which cells generate energy. Carbon dioxide is produced as a waste product during cellular respiration and is also used by plants during photosynthesis. Glucose is a simple sugar that serves as a source of energy for cells. Nitrogen gas, on the other hand, is not directly usable by most organisms and needs to be converted into other forms, such as ammonia or nitrate, before it can be utilized.

The given DNA sequence "T A C A T G C C C T C A A G G" is transcribed into mRNA by replacing each DNA base with its complementary RNA base. Therefore, the correct mRNA transcript would be "AUG UAC GGG AGU UCC".