1.
If an organism has a vestigial structure, that structure likely once had a function in a(n)
Correct Answer
A. Earlier ancestor.
Explanation
If an organism has a vestigial structure, it means that the structure is present in the organism but no longer serves a function. This suggests that the structure was once functional in an earlier ancestor but has become reduced or lost its original purpose over time. Therefore, the correct answer is "earlier ancestor."
2.
Which of the following is a term for a group of similar organisms that can reproduce and produce fertile offspring?
Correct Answer
C. Species
Explanation
A species is a term used to describe a group of similar organisms that can reproduce and produce fertile offspring. This means that members of the same species are capable of mating and producing offspring that can also reproduce. This concept is important in biology as it helps classify and understand the diversity of life on Earth.
3.
The difference in the physical traits of an individual from those of other individuals in a group is called a(n)
Correct Answer
A. Variation.
Explanation
The correct answer is variation. Variation refers to the differences in physical traits among individuals within a group. It is a natural occurrence that allows for diversity within a species and can be caused by genetic factors, environmental influences, or a combination of both. Change refers to a difference over time, adaptation refers to a trait that helps an organism survive in its environment, and species refers to a group of organisms that can interbreed and produce fertile offspring.
4.
Which of the following is a fossil?
Correct Answer
A. A preserved trace of an dead organism.
Explanation
The correct answer is "a preserved trace of a dead organism." A fossil is a remnant or evidence of an organism that lived in the past, such as bones, shells, imprints, or tracks. It is formed through the process of fossilization, where the remains or traces of the organism are preserved in sediment or rock over time. Fossils provide valuable information about the history of life on Earth and can help scientists understand the evolution and biodiversity of different species.
5.
What type of selection occurs when individuals in a population with the intermediate phenotype are selected for?
Correct Answer
B. Stabilizing selection
Explanation
Stabilizing selection occurs when individuals with the intermediate phenotype are selected for. This means that extreme phenotypes are selected against, leading to a reduction in genetic variation within the population. This type of selection favors the average phenotype and helps to maintain the stability of the population's characteristics over time.
6.
The combined alleles of all the individuals in a population is called the ___.
Correct Answer
B. Gene pool
Explanation
The combined alleles of all the individuals in a population is referred to as the gene pool. This term encompasses the total genetic variation present within a population and includes all the different alleles for each gene. The gene pool is important for understanding the genetic diversity of a population and how it can change over time through processes such as natural selection, genetic drift, and gene flow.
7.
Which effect of natural selection is depicted in the graph?
Correct Answer
A. Directional selection
Explanation
The effect of natural selection depicted in the graph is directional selection. This is because the graph shows a shift in the population towards one extreme phenotype over time. This indicates that individuals with that particular phenotype have a higher fitness and are more likely to survive and reproduce, leading to a directional change in the population's characteristics.
8.
Which effect of natural selection is depicted in the graph?
Correct Answer
A. Disruptive selection
Explanation
The graph shows that individuals with extreme traits have higher fitness compared to those with intermediate traits. This indicates that disruptive selection is occurring. Disruptive selection favors the survival and reproduction of individuals at both ends of the trait spectrum, leading to the divergence of the population into two distinct groups.
9.
Which effect of natural selection is depicted in the graph?
Correct Answer
C. Stabilizing selection
Explanation
Stabilizing selection is depicted in the graph because it shows that individuals with intermediate phenotypes have the highest fitness, while individuals with extreme phenotypes have lower fitness. This means that natural selection is favoring the average phenotype and selecting against extreme variations. As a result, the population becomes more genetically uniform over time, leading to a reduction in phenotypic variation.
10.
When a few individuals start a new colony, it most likely results in ...
Correct Answer
A. Genetic drift through the founder effect.
Explanation
When a few individuals start a new colony, it most likely results in genetic drift through the founder effect. This is because the small group of individuals that establish the colony will have a limited genetic diversity compared to the original population. As a result, certain traits and alleles may become more or less common in the new population due to chance alone, leading to genetic drift. This process is known as the founder effect.
11.
The movement of alleles from one population to another is called ___.
Correct Answer
C. Gene flow
Explanation
Gene flow refers to the movement of alleles from one population to another. This can occur through the migration of individuals, who carry their genetic material with them and introduce it to a new population. Gene flow is an important mechanism in evolution as it introduces new genetic variation into populations and can counteract the effects of genetic drift or natural selection. It helps to maintain genetic diversity and can lead to the spread of beneficial alleles throughout a species.
12.
Which of the five mechanisms of evolution is illustrated in the following scenario: A change in body color enabled animals to better hide from predators.
Correct Answer
A. Natural selection
Explanation
The correct answer is natural selection. Natural selection is the mechanism of evolution that favors individuals with traits that increase their chances of survival and reproduction. In this scenario, the change in body color allowed animals to better hide from predators, increasing their chances of survival. Over time, individuals with this advantageous trait would be more likely to survive and pass on their genes, leading to a higher frequency of the trait in the population. This process is an example of natural selection.
13.
When a male bird of paradise displays its tail feathers, it is exhibiting ____ behavior.
Correct Answer
B. Intersexual selection
Explanation
When a male bird of paradise displays its tail feathers, it is exhibiting intersexual selection behavior. This is because intersexual selection refers to the process in which individuals of one sex choose mates based on certain desirable traits or behaviors displayed by the opposite sex. In this case, the male bird is displaying its elaborate and colorful tail feathers to attract and impress the female birds, thus increasing its chances of mating.
14.
When an individual ___ from its population, the genetic diversity of the population decreases.
Correct Answer
A. Emigrates
Explanation
When an individual emigrates from its population, it means that it leaves and moves to a different location or population. This results in a decrease in the genetic diversity of the original population because the genetic material of the emigrant is no longer present. As a result, there is a loss of genetic variation within the population, which can have implications for the overall health and adaptability of the population in the long run.
15.
___ is a type of reproductive isolation in which differing mating rituals prevent individuals from different populations from mating.
Correct Answer
B. Behavioral isolation
Explanation
Behavioral isolation is a type of reproductive isolation where individuals from different populations are prevented from mating due to differences in their mating rituals. This means that the behaviors and signals used by individuals during courtship and mating are specific to their own population and may not be recognized or responded to by individuals from other populations. As a result, individuals from different populations are unable to successfully mate and produce offspring, leading to reproductive isolation between these populations.
16.
___ is a type of evolution in which organisms change in response to other organisms with which they have ecological relationships.
Correct Answer
A. Coevolution
Explanation
Coevolution is the correct answer because it refers to the process in which two or more species evolve in response to each other. This can occur through mutualistic relationships, such as the coevolution between flowers and their pollinators, or through antagonistic relationships, such as the coevolution between predators and their prey. In coevolution, the changes in one species can drive adaptations in another species, leading to a reciprocal evolutionary relationship between them.
17.
The process by which new species arise from prior species is known as ___.
Correct Answer
C. Speciation
Explanation
Speciation refers to the process by which new species emerge from existing ones. It involves the accumulation of genetic changes over time, leading to the development of distinct populations that can no longer interbreed and produce fertile offspring. This process can occur through various mechanisms such as geographic isolation, genetic mutations, and natural selection. Speciation is a fundamental concept in evolutionary biology and helps to explain the incredible diversity of life on Earth.
18.
The differences between members of the same species are known as ___.
Correct Answer
A. Variations
Explanation
Variations refer to the differences that exist among individuals of the same species. These differences can be in terms of physical attributes, behavior, or genetic makeup. Variations are a result of genetic and environmental factors, and they contribute to the diversity within a species. Adaptations, on the other hand, are specific traits that help an organism survive and reproduce in its environment. Mutations are changes in the DNA sequence that can lead to variations. Genetic isolation refers to the separation of a population from others, leading to the development of unique genetic characteristics.
19.
A ___ is a group of individuals of the same species in the same geographic area.
Correct Answer
B. Population
Explanation
A population refers to a group of individuals of the same species that occupy the same geographic area. This term is commonly used in ecology and biology to describe the number and characteristics of organisms within a specific area. It helps scientists study the dynamics, distribution, and interactions of a particular species within a given habitat.
20.
The process by which individuals that are better suited to their environment survive and reproduce more successfully than others is known as ___.
Correct Answer
A. Natural selection
Explanation
Natural selection is the process by which individuals that are better adapted to their environment have a higher chance of survival and reproduce more successfully, passing on their advantageous traits to the next generation. This leads to the gradual accumulation of favorable traits in a population over time. Sexual selection refers to the selection of traits based on their attractiveness to potential mates, genetic drift refers to the random change in allele frequencies in a population, and gene flow refers to the transfer of genetic material between different populations.
21.
Scientists attemp to date fossils by examining the radioactive isotopes. This method is called ___.
Correct Answer
A. Radiometric dating
Explanation
Radiometric dating is the correct answer because it refers to the method of determining the age of fossils by analyzing the radioactive isotopes present in them. This technique relies on the decay of unstable isotopes into stable ones at a known rate, allowing scientists to estimate the age of the fossil based on the amount of decay that has occurred. Relative dating and geologic time scaling are other methods used to determine the age of fossils, but they do not involve the analysis of radioactive isotopes. Speed dating is unrelated to the scientific process of dating fossils.
22.
A population that is not undergoing natural selection displays what type of distribution?
Correct Answer
D. Normal
Explanation
A population that is not undergoing natural selection displays a normal distribution. This means that the majority of individuals in the population have traits that fall within the average range, with fewer individuals having extreme or unusual traits. In a normal distribution, the traits in the population are evenly distributed around the mean, creating a bell-shaped curve. This indicates that there is no selective pressure favoring specific traits, resulting in a balanced distribution of traits within the population.
23.
Which term means the crossing of two different species that share common genes?
Correct Answer
A. Hybridization
Explanation
Hybridization refers to the process of crossing two different species that share common genes. This can occur naturally or be intentionally done by humans for various purposes such as creating new plant varieties or studying genetic traits. Through hybridization, genetic material from both parent species combines, resulting in offspring that exhibit traits from both species. This process is commonly used in agriculture and breeding programs to introduce desirable traits into new generations.
24.
Genetic variation can arise from a random change in the DNA of a gene. This change is called a(n) ___.
Correct Answer
A. Mutation
Explanation
Genetic variation can occur when there is a random change in the DNA of a gene, which is known as a mutation. Mutations can introduce new genetic material or alter existing genetic material, leading to differences in traits among individuals. This variation is essential for the process of evolution, as it provides the raw material for natural selection to act upon. Gene flow refers to the transfer of genetic material between different populations, gene pool refers to the total collection of genes in a population, and allele refers to the different forms of a gene that can exist.
25.
The development by scientists of a new color in a rose is the result of
Correct Answer
A. Artificial selection
Explanation
Artificial selection refers to the process in which humans intentionally select and breed certain organisms with desirable traits to produce offspring with those traits. In the context of the question, scientists developing a new color in a rose would involve selectively breeding roses with specific color traits over multiple generations, ultimately resulting in the desired color. This process is a deliberate manipulation by humans and not a natural occurrence, hence the correct answer is artificial selection.
26.
A measure of how commonly a particular allele occurs in a population is known as the ___.
Correct Answer
B. Allele frequency
Explanation
Allele frequency refers to the proportion of a specific allele in a population. It is a measure of how commonly an allele occurs within a population. This frequency is determined by the number of individuals in the population carrying that allele. By studying allele frequencies, scientists can gain insights into the genetic diversity and evolution of a population.
27.
Two organisms that are closeley related would have ___.
Correct Answer
A. Very similar DNA sequences
Explanation
Two organisms that are closely related would have very similar DNA sequences. This is because DNA contains the genetic information that determines the traits and characteristics of an organism. Organisms that are closely related share a common ancestor and therefore have a high degree of similarity in their DNA sequences. These similarities can be observed through various techniques such as DNA sequencing and comparison. By comparing the DNA sequences of closely related organisms, scientists can gain insights into their evolutionary relationships and understand how they have diverged over time.
28.
Approximately how long has Homo sapiens been on Earth?
Correct Answer
B. 200,000 years
Explanation
Homo sapiens, the modern human species, has been on Earth for approximately 200,000 years. This is supported by scientific evidence and archaeological findings that suggest the emergence of anatomically modern humans around this time. Through the study of fossils, genetic analysis, and other scientific methods, researchers have been able to estimate the age of our species and trace our evolutionary history back to this timeframe.
29.
In the following scientific name, which word indicates the genus of the organism?
Panthera tigris
Correct Answer
A. Panthera
Explanation
The word "Panthera" indicates the genus of the organism.