1.
The sun’s energy feeds all people. Explain your choice.
2.
List one meal in which you ate at three tropic levels (if you’re vegetarian, make up one)
3.
Could autotrophs survive without heterotrophs? Why or why not?
4.
Define the following terms, Photosynthesis and Cellular Respiration. Explain the relationship of these two terms and its importance to us. You may include a diagram.
5.
Explain the movement of Energy in Ecosystems. Compare and contrast this movement to matter (nutrients). You may use diagrams in your answer.
6.
Mr. and Mrs. Anderson both have tightly curled hair. (The hair form gene shows incomplete dominance. There are two alleles, curly and straight. The heterozygote has wavy hair.) The Andersons have a child with wavy hair. Mr. Anderson accuses Mrs. Anderson of being unfaithful to him. Is he necessarily justified? Why or why not?
7.
Colorblindness is an X-linked trait, and the normal allele is dominant to the colorblindness allele. Ethan is colorblind. His wife, Edna, is homozygous for the normal color vision allele. If they have eight children, how many of them would you expect to be colorblind? Using Punnett squares, find and compare the genotypic and phenotypic ratios expected for the offspring of this marriage.
8.
An allele that prevents other alleles from expressing traits is
Correct Answer
A. Dominant
Explanation
The correct answer is dominant because dominant alleles are able to express their traits even in the presence of other alleles. In other words, if an organism carries one dominant allele and one recessive allele for a particular trait, the dominant allele will be expressed. This is because the dominant allele masks the expression of the recessive allele. Therefore, the dominant allele prevents other alleles from expressing their traits.
9.
In terms of evolution, a species can be defined as
Correct Answer
B. A group of individuals that can interbreed and produce fertile offspring
Explanation
In terms of evolution, a species is defined as a group of individuals that can interbreed and produce fertile offspring. This definition is based on the concept of reproductive isolation, which means that members of the same species are able to successfully mate and produce offspring that are capable of reproducing themselves. This reproductive compatibility ensures that genetic material is shared within the species, allowing for the transmission of traits and adaptations over generations. This definition also distinguishes one species from another, as individuals from different species are typically unable to produce fertile offspring when they interbreed.
10.
If a pea plant’s alleles for height are tt, what is true of its parents?
Correct Answer
C. Both parents contributed a recessive allele.
Explanation
If a pea plant's alleles for height are tt, it means that both alleles for height in the plant are recessive. Since an individual inherits one allele from each parent, if both alleles are recessive, it means that both parents must have contributed a recessive allele for height.
11.
The process of survival and reproduction of organisms becoming most fit to their environment is
Correct Answer
D. Natural selection
Explanation
Natural selection is the process by which organisms that are best adapted to their environment are more likely to survive and reproduce, passing on their advantageous traits to future generations. This process leads to the gradual evolution of species over time, as individuals with beneficial characteristics are selected for and become more prevalent in a population. Natural selection is driven by the variations that exist within a population, with those individuals possessing traits that increase their fitness being more likely to survive and pass on their genes.
12.
In pea plants, smooth pods are dominant to wrinkled pods, and green pods are dominant to yellow pods. Two pea plants with smooth green pods are crossed.Both plants are heterozygous for pod texture and pod color.Which phenotype ratio in the offspring is most likely?
Correct Answer
A. 9 smooth green : 3 smooth yellow : 3 wrinkled green : 1 wrinkled yellow
Explanation
When two pea plants with smooth green pods are crossed, the phenotype ratio in the offspring is most likely 9 smooth green : 3 smooth yellow : 3 wrinkled green : 1 wrinkled yellow. This is because smooth pods and green color are dominant traits, so the offspring will have a higher chance of inheriting these traits. The ratio is determined by the combination of alleles from the parents, with the heterozygous plants having a mix of dominant and recessive alleles.
13.
Which of the following statements could explain the change in population size in region X?
Correct Answer
A. Birth rate is greater than death rate
Explanation
The population size in region X is likely increasing because the birth rate is greater than the death rate. This means that more individuals are being born than are dying, resulting in a net population gain.
14.
Which best describes the process illustrated below?
Correct Answer
B. The process of artificial selection
Explanation
The process illustrated in the image is artificial selection. Artificial selection is a process where humans intentionally select certain traits in plants or animals through breeding in order to produce offspring with desired characteristics. In the image, it appears that specific traits or features are being deliberately chosen and bred, which aligns with the concept of artificial selection.
15.
A purebred tall pea plant is crossed with a purebred short pea plant, and the offspring are all tall. What is the genotype of the offspring (assuming pea plant height is a single gene trait)?
Correct Answer
A. Heterozygous
Explanation
When a purebred tall pea plant is crossed with a purebred short pea plant and all the offspring are tall, it suggests that the tall trait is dominant over the short trait. Therefore, the genotype of the offspring is heterozygous, meaning they have one dominant allele (T) for tallness and one recessive allele (t) for shortness.
16.
Ms. Conklin hypothesizes that a study guide will help her students do better on their final exams. She only gives period 6 a study guide. The students who do not get the study guide are her
Correct Answer
D. Control group
Explanation
In this scenario, Ms. Conklin is conducting an experiment to test her hypothesis. She wants to determine if providing a study guide will improve her students' performance on their final exams. To do this, she divides her students into two groups - period 6, which receives the study guide, and the other group, which does not receive the study guide. The group that does not receive the study guide is called the control group. By comparing the performance of the control group with the period 6 group, Ms. Conklin can determine if the study guide had any effect on the students' final exam scores.
17.
The students’ performance on the midterm is Ms. Conklin’s
Correct Answer
A. Dependent variable
Explanation
The students' performance on the midterm is the dependent variable because it is the outcome that is being measured and is expected to change based on the independent variable, which is not mentioned in the question. The dependent variable is the variable that is influenced or affected by the independent variable.
18.
Which of the following most likely resulted when (invasive) brown tree snakes were introduced to Guam?
Correct Answer
B. Many bird populations disappeared.
Explanation
When invasive brown tree snakes were introduced to Guam, many bird populations disappeared. This is likely because the brown tree snakes prey on birds, eggs, and nestlings, leading to a decline in bird populations. The snakes have caused significant ecological disruption on the island, where they have no natural predators and have negatively impacted the native bird species. Their introduction has resulted in a loss of biodiversity and a decrease in the number of bird species on Guam.
19.
Brad jumps into a cold swimming pool and his body temperature goes down. His muscles, blood vessels and nervous system work together to restore his body temperature. Which term best describes this process?
Correct Answer
C. Homeostasis
Explanation
Homeostasis is the best term to describe the process of Brad's muscles, blood vessels, and nervous system working together to restore his body temperature. Homeostasis refers to the body's ability to maintain a stable internal environment despite external changes. In this case, Brad's body is working to regulate his body temperature and bring it back to a normal level after jumping into the cold swimming pool.
20.
A particular genetic disorder leads to very high levels of cholesterol (a fat) in the blood. The gene linked to this trait has only two alleles, N and S. The table below shows the three possible combinations of how these alleles can be expressed. GenotypePhenotypeNNNormal cholesterol levelsNSSlightly elevated cholesterol levelsSSGreatly elevated cholesterol levels Which of the following statements describes the inheritance pattern of the N and S alleles?
Correct Answer
B. The N allele is incompletely dominant to the S allele.
Explanation
The N allele is incompletely dominant to the S allele because individuals with the NN genotype have normal cholesterol levels, individuals with the NS genotype have slightly elevated cholesterol levels, and individuals with the SS genotype have greatly elevated cholesterol levels. This indicates that the phenotype of the heterozygous NS genotype is intermediate between the two homozygous genotypes, suggesting incomplete dominance.
21.
Wolves were reintroduced into Yellowstone National Park in 1995. Wolves hunt elk, but the elk population in the park has declined more than it was expected to decline from direct predation by wolves.Other than direct predation, which of the following factors most likely contributed to the decline in elk population?
Correct Answer
A. Decreased birth rate in elk
Explanation
The most likely factor contributing to the decline in elk population, other than direct predation by wolves, is the decreased birth rate in elk. With the reintroduction of wolves, elk may experience increased stress levels, leading to a decrease in their reproductive success. This can result in a lower birth rate among elk, ultimately contributing to the decline in their population.
22.
A student views cells from several different prokaryotic and eukaryotic organisms under a microscope. Which of the following statements describes how the prokaryotic cells appear different from the eukaryotic cells?
Correct Answer
B. The prokaryotic cells do not have nuclei.
Explanation
The correct answer is that the prokaryotic cells do not have nuclei. This is because prokaryotic cells, such as bacteria, lack a membrane-bound nucleus. In contrast, eukaryotic cells, which make up plants, animals, and fungi, have a distinct nucleus that houses their genetic material. The absence of a nucleus is a key characteristic that distinguishes prokaryotic cells from eukaryotic cells.
23.
Fossils typically provide evidence for evolution because
Correct Answer
C. They show patterns of biological change over time.
Explanation
Fossils provide evidence for evolution because they show patterns of biological change over time. Fossils are the preserved remains or traces of ancient organisms, and by studying them, scientists can observe how species have changed and evolved over millions of years. Fossils can reveal the existence of extinct species, transitional forms, and the gradual development of traits. This evidence supports the theory of evolution, as it demonstrates the gradual transformation of life forms over time. The other options are incorrect because Charles Darwin did not invent fossils, fossils can be found in various places besides oceans, and not all fossils contain hair with DNA.
24.
Genes are found on which parts of a cell?
Correct Answer
C. Chromosomes (DNA)
Explanation
Genes are found on chromosomes, which are composed of DNA. Chromosomes are the structures that carry genetic information in the form of genes. Genes are specific segments of DNA that contain instructions for the synthesis of proteins. Therefore, the correct answer is chromosomes (DNA).
25.
Which of the following is NOT a monomer of nucleotides?
Correct Answer
A. Sugar (ribose)
Explanation
The correct answer is sugar (ribose). Nucleotides are composed of three components: a sugar molecule (ribose or deoxyribose), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). Lipids, on the other hand, are not monomers of nucleotides. They are a diverse group of molecules that include fats, oils, and waxes. Therefore, lipids are not a monomer of nucleotides.
26.
In a chemical reaction, the subscript tells us:
Correct Answer
B. The number of atoms in one molecule.
Explanation
The subscript in a chemical reaction tells us the number of atoms in one molecule. Subscripts are used to indicate the ratio of atoms in a compound. For example, in the chemical formula H2O, the subscript 2 indicates that there are two hydrogen atoms bonded to one oxygen atom in each water molecule. This information is important for understanding the stoichiometry of a reaction and determining the amounts of reactants and products involved.
27.
A buffer is
Correct Answer
C. Can either bind OH- or H+ ions.
Explanation
A buffer is a substance that can either bind OH- (hydroxide) ions or H+ (hydrogen) ions. By doing so, it helps to maintain the pH of a solution within a certain range, preventing drastic changes in acidity or alkalinity. This is important in biological systems, such as human blood, where maintaining a stable pH is crucial for proper functioning. A buffer can either accept or donate H+ ions to maintain the pH balance, making it capable of binding both OH- and H+ ions.
28.
Which of the following is NOT true of one water molecule:
Correct Answer
A. Contains hydrogen bonds
Explanation
A water molecule does not contain hydrogen bonds. Hydrogen bonds are formed between water molecules due to the attraction between the positively charged hydrogen atom of one water molecule and the negatively charged oxygen atom of another water molecule. However, within a single water molecule, there are covalent bonds between the hydrogen and oxygen atoms.
29.
Which of the following is the best general representation of a synthesis reaction?
Correct Answer
B. A + B --> AB
Explanation
A synthesis reaction is a type of chemical reaction where two or more substances combine to form a single product. In the given options, the reaction A + B --> AB represents a synthesis reaction because two reactants (A and B) combine to form a single product (AB). This reaction follows the general pattern of a synthesis reaction, making it the best representation among the given options.
30.
An acid added to a base reacts in a double displacement reaction. ____________
Correct Answer
A. True
Explanation
When an acid is added to a base, they undergo a double displacement reaction. In this reaction, the hydrogen ions (H+) from the acid combine with the hydroxide ions (OH-) from the base to form water (H2O). At the same time, the remaining ions from the acid and the base combine to form a salt. This reaction is commonly known as neutralization and is a characteristic property of acids and bases. Therefore, the statement "An acid added to a base reacts in a double displacement reaction" is true.
31.
A cation is formed when an element loses electrons. ____________
Correct Answer
A. True
Explanation
A cation is formed when an element loses electrons because cations are positively charged ions, and the loss of electrons results in a net positive charge.
32.
Ionic bond is to compound as covalent bond is to molecule. ____________
Correct Answer
A. True
Explanation
The statement is true because an ionic bond is a type of chemical bond that occurs between two oppositely charged ions, resulting in the formation of a compound. On the other hand, a covalent bond is a type of chemical bond that occurs when two atoms share electrons, resulting in the formation of a molecule. Therefore, the analogy presented in the statement is accurate, making the answer "True".
33.
Water with a pH of 8 is slightly acidic. ____________
Correct Answer
B. False
Explanation
Water with a pH of 8 is actually slightly alkaline, not acidic. Acidity increases as the pH value decreases, so a pH of 8 indicates a basic solution.
34.
Covalent bonds strongly hold atoms together because one or more electrons are transferred from one atom to the other. ____________
Correct Answer
B. False
Explanation
Covalent bonds strongly hold atoms together because they involve the sharing of electrons between atoms, rather than the transfer of electrons from one atom to another. In a covalent bond, the atoms involved share their electrons in order to achieve a more stable electron configuration. This sharing of electrons creates a strong bond between the atoms, resulting in a stable molecule. Therefore, the correct answer is False, as covalent bonds do not involve the transfer of electrons.
35.
​Electrons have approximately the same mass as protons, but they have the opposite charge. _______
Correct Answer
B. False
Explanation
Electrons have a significantly smaller mass compared to protons. While protons have a positive charge, electrons have a negative charge. Therefore, the statement that electrons have approximately the same mass as protons, but have the opposite charge, is false.
36.
The identity of a chemical element is determined by its atomic mass. ____________
Correct Answer
B. False
Explanation
The identity of a chemical element is not solely determined by its atomic mass. While the atomic mass is an important characteristic of an element, it is not the only factor that determines its identity. Other properties such as the number of protons in the nucleus (atomic number) and the arrangement of electrons also play a crucial role in identifying an element. Therefore, the statement is false.