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Practice problems Case 21
The tiny water flea, Daphnia, is placed in a petri dish under a dissecting microscope. Two minutes after the light has been turned on, the heartbeat is counted for 15 seconds at two-minute intervals. After ten minutes, the Daphnia is removed from the dish and returned to a specimen jar. • What question is this experiment designed to test? • A. What is the effect of light on the movement of Daphnia? • B. What is the effect of increasing heat on the heart rate of Daphnia? • C. How is the circulation of Daphnia affected when placed in a petri dish? • D. How is the heart rate of Daphnia affected by different amounts of water?
Which tool would make the most accurate measurement of 0.5 mL of hydrogen peroxide? • A. 200-mL Erlenmeyer flask • B. 10-mL test tube • C. 2-mL pipette • D. 50-mL beaker
A farmer wants to sell his recipe for organic fertilizer to a farming supply company. To show its effectiveness, the farmer runs a comparison study against the leading commercial fertilizer. He sets up 3 groups of 5 tomato plants. One group is treated with the farmer’s fertilizer; one with the commercial fertilizer; and the other group is not treated. All other conditions are kept constant. • The farmer observed more tomatoes on the plants with his fertilizer. They were also bigger than the other plants. The supply company claims the farmer’s study is invalid. What scientific reason does the company have to make this claim? • A. The farmer’s study did not include data on the height of the plants. • B. The farmer did not promote his fertilizer to enough companies to receive an offer. • C. The farmer needed a chemist to write out the chemical formula • D. The farmer’s study should have included a larger sample of plants and multiple fertilizers
Students are conducting an investigation to see which plant food causes plants to produce the most flowers • Which of the following would make this a controlled experiment? • A. Use different plant foods on each group of plants. • B. Give one group of plants water without plant food. • C. Give all plants equal amounts of water with plant food. • D. Use a different variety of plants for each type of plant food.
Students investigate how soil pH affects the height of tomato plants. Each of the 6 tomato plants receives the same amount of light each day and is planted in the same size pot and given the same amount of water. Each plant is planted in soil with a different pH. • What is the dependent variable? • A. The size of the pot in which the plants are grown • B. The pH of the soil in which the plants are grown • C. The amount of water given to the tomato plants • D. The height to which the tomato plants grow.
John Needham performed a series of experiments based on Redi’s experiment to support the theory of spontaneous generation. In his experiment, Needham boiled different kinds of broth in flasks, sealed them, and then let the broth cool. Microorganism developed in the broth, providing Needham with the evidence of spontaneous generation. • Even though Needham’s results supported the theory, what criticism did other scientists have about the experiment? • A. The experiments were conducted only once. • B. A greater variety of broth should have been tested • C. Sterile flasks should have been used in the experiments • D. The broth was contaminated before the flasks were sealed.
After a protein is constructed at the ribosome, it can be transported to the Golgi complex for modification • What cell structure is used in this transport? • A. Lysosome • B. Mitochondrion • C. Nuclear pore • D. Endoplasmic reticulum
In a water molecule, the oxygen atom has a slightly negative charge and the hydrogen atoms have a slightly positive charge. • This charge difference gives rise to which type of bonds between water molecules? • A. Ionic bonds • B. Hydrogen bonds • C. Single covalent bonds • D. Double covalent bonds
In a cell, which molecule is used as a messenger to carry instructions from the nucleus into the cytoplasm? • A. ADP • B. DNA • C. RNA • D. ATP
What part of the cell has a similar function to a school security guard, whose job is to control who enters and leaves the school? • A. Nucleus • B. Golgi body • C. Mitochondrion • D. Cell membrane
Which of the following correctly sequences the level of organization from the simplest to the most complex in a multicellular organism? • A. Organ -> system -> cell -> tissue • B. Organ -> tissue -> system -> cell • C. Cell -> tissue -> organ -> system • D. Cell -> system -> tissue -> organ
When red blood cells are placed in distilled water, the cells swell as water molecules enter them. • By what process do water molecules move into cells? • A. Facilitated diffusion • B. Active transport • C. Endocytosis • D. Osmosis
Which molecule has a structure with a ratio of 2 hydrogen to 1 oxygen? • A. Carbohydrate • B. Nucleic Acid • C. Lipid • D. Protein
Many organisms maintain a constant pH in parts of their body by neutralizing acids and bases. • The neutralization is performed by which of the following? • A. Buffer solutions • B. Water molecules • C. Na+ and K+ ions • D. O2 and CO2 molecules
Two components of cell membranes are phospholipids and proteins • Which of these is a basic difference in the two components? • A. Phospholipids are solid, but proteins are fluid • B. Phospholipids transport water while proteins transport fats • C. Phospholipids provide instructions and proteins follow these instructions • D. Phospholipids allow simple diffusion, but proteins are used in facilitated diffusion
Which of these describes the level of organization of the digestive system? • A. Different tissues carrying out similar functions • B. Similar cells contributing to a particular function • C. Different organs working together to perform a particular function • D. Similar organelles working together to perform different functions
Which statement describes a characteristic of aerobic respiration? • A. Does not require oxygen • B. Uses ATP to produce oxygen • C. Produces 36 molecules of ATP • D. Uses carbon dioxide to produce glucose
If mouse cells have 40 chromosomes, how many do the egg cells have? • A. 10 • B. 20 • C. 40 • D. 80
Which statement describes the overall process of meiosis? • A. A haploid cell produces 2 haploid cells • B. A diploid cell produces 2 diploid cells • C. A haploid cell produces 4 diploid cells • D. A diploid cell produces 4 haploid cells
In which phase of mitosis does the chromatin become condensed into short, rod-like structures that can be seen easily with a microscope? • A. Anaphase • B. Metaphase • C. Prophase • D. Telophase