1.
Which of the following statements about cells is true?
Correct Answer
D. All of the above
Explanation
The statement "All of the above" is the correct answer because it accurately summarizes the preceding statements. The first statement states that cells contain all the materials necessary for life, which is true as cells are the basic units of life. The second statement states that cells are found in all organisms, which is also true as cells are the building blocks of all living organisms. The third statement states that cells are sometimes specialized for particular functions, which is true as different cells in an organism can have specific roles and functions. Therefore, all three statements are true, making "All of the above" the correct answer.
2.
Which of the following statements about all living things is true?
Correct Answer
B. All living things have one or more cells
Explanation
All living things have one or more cells because cells are the basic building blocks of life. All living organisms, from single-celled bacteria to complex multicellular organisms, are composed of cells. Cells carry out essential functions necessary for life, such as metabolism, growth, and reproduction. Therefore, it is true that all living things have one or more cells.
3.
Organisms must have food because
Correct Answer
A. Food is a source of energy
Explanation
Food is a source of energy for organisms. When organisms consume food, it is broken down through digestion, and the nutrients are absorbed into the bloodstream. These nutrients, such as carbohydrates, proteins, and fats, are then used by cells to produce energy through cellular respiration. This energy is essential for various biological processes, including growth, repair, and movement. Therefore, food is necessary for organisms to obtain the energy they need to survive and function properly.
4.
A change in an organism's environment that affects the organism's activities is a
Correct Answer
B. Stimulus
Explanation
A stimulus refers to a change in an organism's environment that triggers a response or affects the organism's activities. It can be any external factor such as temperature, light, sound, or chemical substances that elicits a reaction from the organism. This response can be behavioral, physiological, or developmental. The stimulus can either be positive, promoting a response, or negative, inhibiting a response. Therefore, the correct answer is stimulus.
5.
Organisms store energy in
Correct Answer
C. Lipids
Explanation
Lipids are molecules that store energy in the body. They are a type of organic compound that includes fats, oils, and waxes. Lipids are an efficient way to store energy because they contain more than twice as much energy as carbohydrates or proteins. When the body needs energy, it can break down lipids through a process called lipid metabolism, releasing the stored energy for use. Therefore, lipids are the correct answer for this question.
6.
The molecule that contains the information about how to make proteins is
Correct Answer
C. DNA
Explanation
DNA is the correct answer because it carries the genetic information that contains instructions for making proteins. DNA molecules consist of nucleotides, which are made up of a sugar, a phosphate group, and a nitrogenous base. The sequence of these bases in DNA determines the sequence of amino acids in proteins, thus encoding the information needed for protein synthesis. ATP is a molecule that provides energy for cellular processes, carbohydrates are a source of energy, and phospholipids are structural components of cell membranes, but they do not contain the specific information required for protein synthesis.
7.
The subunits of nucleic acids are
Correct Answer
A. Nucleotides
Explanation
Nucleic acids are composed of repeating units called nucleotides. Nucleotides consist of three main components: a sugar molecule (either ribose or deoxyribose), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, guanine, or uracil). These nucleotides are joined together through phosphodiester bonds to form the backbone of DNA and RNA molecules. Therefore, nucleotides are the correct subunits of nucleic acids.
8.
Plants store extra sugar as
Correct Answer
B. Starch
Explanation
Plants store extra sugar as starch because starch is a complex carbohydrate made up of multiple glucose units. It is the most common form of stored energy in plants and serves as a reserve for later use. Starch is insoluble in water, allowing it to be stored in plant cells without affecting the osmotic balance. When energy is needed, starch can be broken down into glucose molecules and used for various metabolic processes, such as respiration or synthesis of other molecules.
9.
Homeostasis means maintaining
Correct Answer
A. Stable internal conditions
Explanation
Homeostasis refers to the ability of an organism to maintain a stable internal environment despite changes in the external environment. This includes regulating factors such as temperature, pH levels, and nutrient balance. By maintaining stable internal conditions, an organism can ensure proper functioning of its cells and organs, allowing it to survive and thrive in its environment.
10.
Which of the following is NOT a characteristic of living things?
Correct Answer
C. Living things make their own food
Explanation
Living things make their own food is not a characteristic of living things. This statement refers to the process of photosynthesis, which is only performed by autotrophic organisms such as plants and some bacteria. While many living things do make their own food, such as plants through photosynthesis, there are also many organisms that cannot produce their own food and rely on consuming other organisms for nutrition. Therefore, making their own food is not a universal characteristic of all living things.