1.
The carbon cycle shows how carbon molecules move between the living and nonliving components of an ecosystem. Which 2 processes of living things move carbon in and out of the environment?
Correct Answer
C. pHotosynthesis and cell respiration
Explanation
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.
2.
Which of the following will decrease the amount of carbon in the environment?
Correct Answer
B. AutotropHs using the process of pHotosynthesis
Explanation
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.
3.
Which of the following are possible consequences of Global Warming? (check all that apply)
Correct Answer(s)
A. Melting of polar ice caps
C. Rising sea levels
D. Unusual climate changes destroying ecosystems
F. Loss of land mass
Explanation
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.
4.
Which best describes the greenhouse effect?
Correct Answer
D. The warming of earth's temperature due to gases that trap heat
Explanation
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.
5.
Which molecules are able to be used by some type of living organisms? Check all that apply.
Correct Answer(s)
A. Oxygen
B. Carbon Dioxide
C. Glucose
Explanation
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.
6.
Which is true about the nitogen cycle?
Correct Answer
A. Bacteria converts unusable nitrogen to a form usable by living things
Explanation
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.
7.
Humans increase the amount of nitrogen in the environment through
Correct Answer
C. Using fertilizer
Explanation
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.
8.
Which is an example of a haploid cell?
Correct Answer
C. Sperm cell
Explanation
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.
9.
Which of the following statements apply to this picture? (check all that apply)
Correct Answer(s)
A. These are homologous chromosomes
B. One chromosome has come from mom and one from dad
D. These chromosomes carry the genes for the same traits
F. These chromosomes are demonstrating the process of crossing over
G. These chromosomes are increasing genetic variation
Explanation
The given picture shows homologous chromosomes because they are paired and have similar size and shape. One chromosome comes from the mother and one from the father, indicating that they are not identical. These chromosomes carry the genes for the same traits, as homologous chromosomes contain similar genes at the same loci. The chromosomes in the picture are demonstrating the process of crossing over, which occurs during meiosis and increases genetic variation by exchanging genetic material between homologous chromosomes.
10.
The process of _____ produces sex cells, while _____ produces body cells
Correct Answer
A. Meiosis, Mitosis
Explanation
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.
11.
A mutation is
Correct Answer
B. A change in DNA
Explanation
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.
12.
Inherited mutations like PKU and sickle cell anemia are passed on through
Correct Answer
D. Sexual reproduction
Explanation
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.
13.
What can cause a mutation? (check all that apply)
Correct Answer(s)
A. Carcinogens
B. Chance
D. Heredity
Explanation
Carcinogens are substances that can cause mutations in DNA, leading to the development of cancer. Chance refers to random errors that can occur during DNA replication, which can also result in mutations. Heredity refers to the inheritance of genetic mutations from parents to offspring. Therefore, all three options - Carcinogens, Chance, and Heredity - can cause mutations. Organic food and long-term disease are not known to directly cause mutations, so they are not correct answers.
14.
The fusion of a sperm cell and egg cell first produces a
Correct Answer
A. Zygote
Explanation
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).
15.
As an embryo develops, cells will begin to become specialized and form tissues that perform certain functions. This is called
Correct Answer
C. Differentiation
Explanation
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.
16.
Your body sweating in order to maintain a certain temperature is an example of
Correct Answer
C. Homeostasis
Explanation
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.
17.
Which of the following allele combinations is homozygous dominant?
Correct Answer
C. GG
Explanation
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).
18.
When genes are located on the X or Y chromosomes the traits are called
Correct Answer
A. Sex-linked
Explanation
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.
19.
A cat with black whiskers (BB) is bred to a cat with white whiskers (bb). What is the probability of the offspring's genotype?
Correct Answer
D. 100% Bb
Explanation
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%.
20.
A cat with black whiskers (BB) is bred to a cat with white whiskers (bb). What is the phenotype of the offspring?
Correct Answer
A. Black whiskered
Explanation
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.
21.
Polygenic traits like skin color and height are
Correct Answer
B. Controlled by multiple genes
Explanation
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.
22.
If the color of seahorses is codominant, then a red sea horse crossed with a white seahorse would result in
Correct Answer
C. Red and white seahorses
Explanation
If the color of seahorses is codominant, it means that both the red and white alleles are equally expressed in the offspring. Therefore, when a red seahorse is crossed with a white seahorse, the offspring would inherit both the red and white alleles, resulting in red and white seahorses.
23.
If the color of seahorses is incompletely dominant, then a red sea horse crossed with a white seahorse would result in
Correct Answer
A. Pink seahorses
Explanation
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.
24.
What is true about the picture above? (check all that apply)
Correct Answer(s)
B. It is a karyotype
C. It is a male
G. It shows an individual with Down's Syndrome
H. It shows chromosomes affected by improper separation during meiosis
Explanation
The picture above is a karyotype because it shows a visual representation of an individual's chromosomes. It is a male because the karyotype displays a set of chromosomes typically found in males. It shows an individual with Down's Syndrome because the karyotype exhibits an extra copy of chromosome 21. It shows chromosomes affected by improper separation during meiosis because the karyotype displays abnormal chromosome arrangement.
25.
When the following strand of DNA replicates, what would the complimentary strand of DNA look like?
A T T C C C G A A T C C C
Correct Answer
B. T A A G G G C T T A G G G
Explanation
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.
26.
What are the base pairs for RNA nucleotides?
Correct Answer
A. A-U, C-G
Explanation
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.
27.
Check all of the following statements that are true about DNA
Correct Answer(s)
A. Stores hereditary information for production of proteins
C. It makes up chromosomes
D. It does not leave the nucleus
F. Replicates itself for cell division
Explanation
DNA stores hereditary information for the production of proteins. It makes up chromosomes, which are structures that contain genetic material. DNA does not leave the nucleus of a cell, as it is primarily located within the nucleus. It replicates itself in a process called DNA replication, which occurs before cell division. However, DNA is not a single strand of nucleotides, as it is actually a double helix structure composed of two strands of nucleotides. Additionally, DNA contains the sugar deoxyribose, not ribose.
28.
When DNA is copied into mRNA, it is called
Correct Answer
B. Transcription
Explanation
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.
29.
Transcription happens in the nucleus of a cell
Correct Answer
A. True
Explanation
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.
30.
When mRNA is read in order to make proteins, it is called
Correct Answer
A. Translation
Explanation
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.
31.
In order to make proteins, amino acids are joined by _____ bonds
Correct Answer
C. Peptide
Explanation
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.
32.
What would be the correct mRNA transcript from the following DNA sequence?
T A C A T G C C C T C A A G G
Correct Answer
D. AUG UAC GGG AGU UCC
Explanation
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".
33.
What is the correct tRNA sequence for the following mRNA sequence?
AUG UAA CCG AAC
Correct Answer
A. UAC AUU GGC UUG
Explanation
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.
34.
What is the correct amino acid sequence from the following mRNA strand? (use codon chart!)
AUG UCU GCU UAC GUA
Correct Answer
C. Met-ser-ala-tyr-val
Explanation
The correct amino acid sequence from the given mRNA strand is "met-ser-ala-tyr-val". This is determined by using a codon chart to translate each codon in the mRNA strand into its corresponding amino acid.
35.
Sometimes mutations do not effect the protein that is being assembled. These mutations
Correct Answer
B. Are silent
Explanation
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.
36.
Identify the type of mutation below:
Normal DNA: ATTCAAGGCATT
Mutated DNA: ATTGAAGGCATT
Correct Answer
C. Substitution
Explanation
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.
37.
Which of the following contribute to genetic variation? (check all that apply)
Correct Answer(s)
A. Jumping genes
B. Crossing over/recombination
C. Deletion or insertion of nucleotides
D. Independent assortment
E. Natural selection
Explanation
Jumping genes, crossing over/recombination, deletion or insertion of nucleotides, independent assortment, and natural selection all contribute to genetic variation. Jumping genes refer to the movement of genetic material within a genome, which can lead to new combinations of genes. Crossing over/recombination occurs during meiosis when genetic material is exchanged between homologous chromosomes, creating new combinations of alleles. Deletion or insertion of nucleotides can result in gene mutations, altering the genetic sequence. Independent assortment refers to the random alignment and separation of homologous chromosomes during meiosis, leading to different combinations of alleles in gametes. Natural selection acts on the variation present in a population, favoring certain traits and leading to evolutionary change.
38.
Which is NOT a reason that populations will evolve?
Correct Answer
C. Traits acquired over a lifetime
Explanation
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.
39.
A population of organisms with a wide variation of traits
Correct Answer
B. Will be more likely to survive a drastic change in the environment
Explanation
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.
40.
Which of the following are used as evidence for evolution? (check all that apply)
Correct Answer(s)
A. Molecular structure
B. Homology
D. Fossils
Explanation
Molecular structure, homology, and fossils are all used as evidence for evolution. Molecular structure refers to the similarities and differences in the DNA and proteins of different species, which can show how closely related they are. Homology refers to the presence of similar structures or traits in different species, suggesting a common ancestor. Fossils provide physical evidence of past life forms and their characteristics, allowing scientists to study the changes that have occurred over time. These three types of evidence provide support for the theory of evolution and the idea that species have changed and diversified over millions of years.
41.
Correct Answer
D. All of the above
Explanation
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.
42.
Genetic drift results in a change of the gene pool of a population. Genetic drift
Correct Answer
B. Increases the evolution of a species
Explanation
Genetic drift is a random process that can cause changes in the gene pool of a population over time. It occurs when certain individuals or traits become more or less common in a population due to chance events, rather than natural selection. This can lead to the evolution of a species by introducing new genetic variations and causing allele frequencies to change. Therefore, the statement "increases the evolution of a species" is a correct explanation of the effects of genetic drift.
43.
All of the following are examples of natural selection EXCEPT
Correct Answer
D. Building muscles with weights and having muscular offspring
Explanation
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.
44.
Check the statements that descibe Darwin's Theory of Natural Selection
Correct Answer(s)
A. Individuals who are better adapted to the environment pass on successful traits
B. Mutation and heredity increase variation in populations
D. Individuals who are most fit reproduce and increase population numbers
Explanation
Darwin's Theory of Natural Selection states that individuals who are better adapted to the environment pass on successful traits. This means that those individuals who have traits that allow them to survive and reproduce in their environment are more likely to pass on these traits to their offspring. Additionally, mutation and heredity increase variation in populations, leading to more diverse traits within a population. Lastly, individuals who are most fit, meaning those who have the best traits for survival and reproduction, will reproduce and increase population numbers.
45.
The finches on the Galapagos Islands have a tremendous diversity in the populations due to environmental pressures and available food sources. What is the likely cause for the beak variations in finch populations?
Correct Answer
A. Natural selection
Explanation
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.
46.
Organisms of the same species in an area is a
Correct Answer
D. Population
Explanation
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.
47.
Anything that restricts the growth of a population is called
Correct Answer
C. Limiting factors
Explanation
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.
48.
How does the introduction of an invasive species such as the zebra mussel affect the environment?
Correct Answer
B. They compete for resources with local populations
Explanation
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.
49.
Which graph shows a population meeting its carrying capacity?
Correct Answer
B. B
Explanation
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.
50.
What does exponential growth indicate about a population?
Correct Answer
D. Unlimited resources
Explanation
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.