1.
A student constructs several terrariums like the one shown. Each terrarium is exposed to a different amount of sunlight each day. In order to determine the ideal amount of sunlight, which of the following variables must be held constant?
Correct Answer
A. Types of plants
Explanation
To determine the ideal amount of sunlight for the terrariums, the variable "types of plants" must be held constant. This is because different types of plants have different sunlight requirements and can tolerate varying levels of exposure. By keeping the types of plants consistent across the terrariums, any differences in the growth and health of the plants can be attributed to the varying amounts of sunlight, allowing for a more accurate determination of the ideal amount.
2.
Bacteria adapt more quickly to environmental changes than elephants. Which best explains this difference?
Correct Answer
B. Bacteria reproduce more rapidly
Explanation
Bacteria reproduce more rapidly than elephants, which allows them to adapt more quickly to environmental changes. This is because bacteria have shorter generation times, meaning they can produce more offspring in a shorter period of time. With each new generation, there is an opportunity for genetic variation and mutations to occur, increasing the chances of beneficial adaptations. In contrast, elephants have longer generation times and produce fewer offspring, limiting their ability to adapt as quickly to changing environments.
3.
The structures labeled B are called ___.
Correct Answer
B. Fatty acids
Explanation
The structures labeled B in this question are called fatty acids. Fatty acids are organic molecules consisting of a hydrocarbon chain and a carboxyl group at one end. They are an important component of lipids, such as triglycerides, and play a crucial role in energy storage and metabolism in living organisms.
4.
The ___ form of this molecule is found in animals and is ___ at room temperature.
Correct Answer
A. Saturated… solid
Explanation
The correct answer is saturated... solid. In organic chemistry, saturated refers to a molecule that contains only single bonds between carbon atoms. These molecules tend to have a higher melting point and are solid at room temperature. Unsaturated molecules, on the other hand, contain at least one double or triple bond between carbon atoms, which results in a lower melting point and a liquid state at room temperature. Therefore, the saturated form of this molecule is found in animals and is solid at room temperature.
5.
If you ate bacon and fried eggs for breakfast, the largest component of the energy would come from the ___.
Correct Answer
D. Lipids
Explanation
If you ate bacon and fried eggs for breakfast, the largest component of the energy would come from lipids. Lipids, also known as fats, are a concentrated source of energy and are found in high amounts in bacon and eggs. Carbohydrates, proteins, and sugars also provide energy, but in this case, lipids would be the main contributor due to the high fat content in bacon and eggs.
6.
Organic compounds ALL contain the element carbon. Which organic compound, used for stored chemical energy, contains carbon, hydrogen, oxygen, and often phosphorous?
Correct Answer
B. Lipids
Explanation
Lipids are organic compounds that contain carbon, hydrogen, and oxygen, and often phosphorous. They are used for stored chemical energy in organisms. This is because lipids have a high energy content and can be broken down to release energy when needed.
7.
Water (H2O) is an example of a molecule whose atoms are held together by which of the following?
Correct Answer
B. Covalent bonds
Explanation
Water (H2O) is an example of a molecule whose atoms are held together by covalent bonds. Covalent bonds occur when atoms share electrons in order to achieve a stable electron configuration. In the case of water, the oxygen atom shares two electrons with two hydrogen atoms, resulting in a stable molecule. Hydrogen bonds, on the other hand, occur between molecules and are weaker than covalent bonds. Ionic bonds involve the transfer of electrons between atoms, and metallic bonds occur between metal atoms.
8.
The specific chemical that an enzyme will act on is called a(n)___.
Correct Answer
C. Substrate
Explanation
An enzyme is a protein that acts as a catalyst, meaning it speeds up chemical reactions. The specific chemical that an enzyme acts on is called a substrate. The enzyme binds to the substrate and helps convert it into a product. The substrate is the molecule that fits into the active site of the enzyme, allowing the enzyme to carry out its specific function. Therefore, the correct answer is substrate.
9.
A bond that is formed when two atoms share electrons is called a ___.
Correct Answer
A. Covalent bond
Explanation
A covalent bond is formed when two atoms share electrons. This type of bond occurs between nonmetal atoms, allowing them to achieve a stable electron configuration by sharing electrons. In a covalent bond, the shared electrons are attracted to both nuclei, creating a strong bond between the atoms. This type of bond is commonly found in molecules and compounds composed of nonmetals.
10.
The picture at the right is an example of a(n) ___.
Correct Answer
C. Atomic model
Explanation
The picture at the right is an example of an atomic model. This is because the picture represents the structure of an atom, showing the arrangement of its protons, neutrons, and electrons. Atomic models are used to visualize and understand the behavior and properties of atoms.