Jordan Biosciences II Final Part 2

The explanation for the given correct answer is that the statement suggests that the finches on San Cristobal Island have a lower level of mitochondrial DNA diversity compared to their finch ancestors in the Americas. This implies that over time, the finches on San Cristobal have experienced genetic bottlenecks or a reduction in genetic variation. This reduction in diversity could be due to factors such as isolation, limited gene flow, or founder effects.

The theory that a meteor impact played a role in the mass extinction of dinosaurs is supported by the discovery of a crater dating to 65 million years ago, shock crystal distributions, a layer of the rare earth element iridium in deposits dating to the time of that mass extinction, and results of computer modeling of volcanic and nuclear incidents. However, the existence of caves near Lascaux in France with sketches, engravings, and paintings depicting events around the time of the event does not directly support the theory of a meteor impact.

The presence of two genetically-distinct morphs in the walking stick population, each with a preference for mating with individuals of the same color pattern, suggests that over time, the species will divide into two distinct species. This is because individuals with different color patterns are less likely to mate with each other, leading to reproductive isolation and the accumulation of genetic differences between the two groups. Eventually, these differences may become significant enough for the two groups to be considered separate species.

The fact that all eukaryotes have mitochondria (or remnants thereof), but not all eukaryotes have chloroplasts, suggests that mitochondria appeared in eukaryotes before the evolution of chloroplasts. This is supported by the observation that chloroplasts have ribosomes that are more similar to prokaryotic ribosomes than to ribosomes found in the cytosol of eukaryotic cells. Additionally, mitochondrial ribosomes vary extensively among different groups of eukaryotes, but they are generally more similar to prokaryotic ribosomes than to their counterparts in the eukaryotic cytoplasm.

The first photosynthetic organisms on earth must have been prokaryotes because they are the simplest and most ancient form of life. Prokaryotes lack a true nucleus and membrane-bound organelles, making them more primitive compared to eukaryotes. Photosynthesis is a fundamental process that converts sunlight into energy, and prokaryotes, such as cyanobacteria, are known to have developed this ability early in Earth's history. Therefore, it is logical to conclude that prokaryotes were the first organisms to carry out photosynthesis.

The correct answer is the ability of individuals to successfully breed with each other. The biological species concept defines a species as a group of organisms that can interbreed and produce fertile offspring. This concept focuses on reproductive compatibility as the key factor in distinguishing species. If individuals can successfully mate and produce viable offspring, they are considered to be members of the same species. This criterion helps to determine the boundaries between different species and assign individuals to specific taxa.

The two populations of flies are kept reproductively isolated because they find different fruits acceptable as stages for courtship dances. This means that each population of flies has specific preferences for the type of fruit they use during courtship rituals. Since they have different preferences, they are unlikely to come into contact with each other and mate, thus remaining reproductively isolated. This preference for different fruits plays a crucial role in preventing gene flow between the two populations, leading to the formation of separate species.

Based on the information provided, the correct answer is that the first true eukaryotic cells existed over 1 billion years ago. This conclusion can be drawn from the phrase "Judging from the fossil record and other evidence," which suggests that scientists have examined various sources of evidence to determine the timeline of the first eukaryotic cells. The fact that these cells are said to have existed over 1 billion years ago indicates that they are believed to have originated in the distant past.

The correct answer suggests that in a population of exclusively Mexican Hairless dogs, the frequency of the hairless allele ("-") would diminish over time but not be entirely lost. This is because individuals with the homozygous condition for the hairless allele do not survive, leading to a decrease in the frequency of this allele in the population. However, since the initial frequencies of the two alleles are equal and artificial selection is not a factor, it is expected that the hairless allele would still persist in the population, albeit at a lower frequency.

The correct answer is that India was a separate continent until about 55 million years ago. This explains why the animals and plants found in modern India differ greatly from those in nearby southeast Asia. The separation of India as a separate continent allowed for the evolution of unique species in India, resulting in the differences observed today.

Cyanobacteria are not chemoautotrophs. Chemoautotrophs are organisms that obtain energy by oxidizing inorganic molecules, while cyanobacteria are photosynthetic, meaning they obtain energy from sunlight. They are representatives of the Bacteria domain and there is genetic evidence suggesting that they are similar to the ancestors of chloroplasts. Their metabolism results in the production of molecular oxygen from water, making them significant contributors to Earth's oxygen levels.

The lack of an ozone layer in the early Earth would have made life in the terrestrial environment impossible. The ozone layer plays a crucial role in protecting life on Earth by absorbing most of the sun's harmful ultraviolet (UV) radiation. Without this protective layer, the intense UV radiation would have reached the surface, causing severe damage to living organisms and preventing the development of complex life forms. Therefore, the absence of an ozone layer would have made it impossible for life to exist on land.

C is also correct

The explanation for the correct answer is that the two populations of bower birds construct different types of bowers and do not interbreed. This suggests that they are reproductively isolated, meaning that they are no longer able to produce viable offspring with each other. This could be due to differences in behavior, mating preferences, or physical characteristics that prevent successful reproduction between the two populations. Reproductive isolation is often a key factor in the formation of new species.

The statement "They are found in New Zealand because the island was once part of a larger land mass which included what is now Europe" is not correct. Red deer are found in New Zealand due to human introduction, not because of a land connection with Europe. This answer choice provides a false explanation for the presence of red deer in New Zealand.

The answer suggests that RNA can act as a catalyst, which means it can facilitate chemical reactions without the need for enzymes. This is significant because it implies that complex organic molecules could have formed on prebiotic earth even in the absence of enzymes. This explanation provides a possible mechanism for the formation of these molecules before enzymes were present.

Mitochondria are membrane-bound organelles found in eukaryotic cells that are responsible for energy production through cellular respiration. Prokaryotes, on the other hand, lack mitochondria. They generate energy through other means, such as glycolysis. Therefore, the statement that "Only eukaryotes have mitochondria" is correct because prokaryotes do not possess this organelle.

If a student guesses at random for each of the 30 questions, there is a 1/4 chance of getting the correct answer for each question (assuming there are 4 choices for each question). Therefore, on average, the student would get 1/4 of the questions correct. Since there are 30 questions in total, the student would get an average of 30 * 1/4 = 7.5 questions correct. To convert this to a score out of 100, we can calculate (7.5/30) * 100 = 25. Therefore, the student would achieve a score of 25.

Fossils that date to 2.5 billion years old include prokaryotes, and eukaryotes including multicellular organisms.

The presence of RNA as the genetic material in both prokaryotes and subcellular organelles like mitochondria and plastids supports the theory that modern eukaryotes evolved from symbiotic relationships involving prokaryotes. This is because it suggests a common ancestry and genetic transfer between these organisms. The other options, such as the resemblance of genetic make-ups, the ability to divide by fission, and similar sizes of subcellular organelles to prokaryotes, also provide evidence for the theory of symbiotic evolution.

The presence of histones associated with genetic material is a characteristic shared by Archaea and Eukarya, but not by Bacteria. This suggests a closer evolutionary relationship between Archaea and Eukarya, as they both have a more complex genetic organization compared to Bacteria. This observation supports the idea that Archaea and Eukarya share a common ancestor and have a more recent common evolutionary history compared to Bacteria.

Based on the data provided, the answer suggests that female Pied flycatchers have a difficult time distinguishing between males of the two species when they are together. This is supported by the statement that male Pied flycatchers have a brown coloration when they appear with Collared males, making them distinct from the blue-grey Collared males. Therefore, the females may struggle to differentiate between the two species when they are in close proximity, leading to potential hybridization and the formation of a single species.

Stromatolites are not representatives of the Archaea. They are actually formed of cyanobacteria, which are a type of bacteria. Stromatolites are layered structures that are formed by the trapping, binding, and cementation of sediment by microbial communities, primarily cyanobacteria. They are known for their ability to carry out photosynthesis and are considered to be one of the earliest evidence of life on Earth.

In small populations with heightened inbreeding, the frequency of homozygous genotypes would increase. This is because inbreeding increases the likelihood of mating between individuals that are genetically similar, leading to an increase in homozygosity. In the Hardy-Weinberg equilibrium, where populations are assumed to be infinitely large, the frequency of genotypes remains constant over generations. However, in small populations with inbreeding, the frequency of homozygous genotypes would increase due to the limited genetic diversity and increased mating between genetically similar individuals.

Based on the two figures provided, it can be observed that there are 14 nucleotide substitutions that distinguish humans and gibbons.

The correct answer is "Differences in the levels of inbreeding and genetic drift are most likely the cause in the differences in reproductive isolation." This statement does not sound reasonable because inbreeding and genetic drift are factors that can lead to decreased genetic diversity within a population, but they are not directly related to reproductive isolation between populations. Reproductive isolation is typically caused by factors such as geographic barriers or differences in mating behaviors and preferences.

B is correct also

Genetic recombination refers to the process of combining genetic material from two different sources, resulting in the formation of new combinations of genes. The given answer states that genetic recombination as a result of transformation is more likely in prokaryotes than eukaryotes. Transformation is a process in which prokaryotic cells take up foreign DNA from their surroundings and incorporate it into their own genome. This ability to incorporate foreign DNA increases the likelihood of genetic recombination in prokaryotes. In contrast, eukaryotes have more complex mechanisms of genetic recombination, such as sexual reproduction and meiosis. Therefore, the statement suggests that prokaryotes have a higher likelihood of genetic recombination through transformation compared to eukaryotes.