An uncharged atom has six electrons. The nucleus of this atom must contain _______ protons.
C. six
What state of matter is best represented by the diagram below?
A. solid
The digestive system is critical to maintaining a healthy body because
C. the digestive system collects the nutrients needed by the body.
Phytoplankton are single-celled, photosynthetic organisms living at the surface of the ocean. How do phytoplankton affect the Earth's carbon and oxygen cycles when they perform photosynthesis?
D. They add oxygen to and remove carbon dioxide from the atmosphere.
The United States Environmental Protection Agency (EPA) has developed several programs to help reduce greenhouse gas emissions and, ultimately, global warming. The SmartWay Transport Partnership targets greenhouse gas reductions in the freight industry. The Combined Heat and Power Partnership focuses on power generation industries. Programs like Clean School Bus USA and the Green Vehicle Guide focus on transportation.
Based on the information above,
B. efforts to reduce global warming involve many different human activities.
The atomic symbols of nitrogen and oxygen are N and O, respectively. The chemical formula of a particular substance is NO2. Which of the following is a correct description of the substance?
D. a compound made up of 1 nitrogen atom and 2 oxygen atoms
What is the function of the cytoplasm?
Adaptations are unique traits developed by organisms to help them survive, thrive, and reproduce in their particular environment. Adaptations may be structural or behavioral. Which of the following is an example of a behavioral adaptation?
C. the migration of birds
A _______ is a segment of DNA that carries a single unit of hereditary information.
C. gene
Which of the following would most likely happen if cost were a constraint during the design process of a new product?
C. The overall quality of the product would decrease.
Which of the following best describes the difference between a mixture and a pure substance?
D. A mixture has different properties throughout; a pure substance has the same properties throughout.
_______ is the passive movement of water molecules across a cell membrane.
D. Osmosis
Offspring that are produced through sexual reproduction are usually similar, but never identical, to their parents. This is because
B. half of the offspring's genes come from one parent while the other half comes from the other parent.
What is produced by the process of meiosis?
B. Cells that contain half of the number of chromosomes present in the parent cell.
When heated, calcium carbonate goes through a chemical reaction, and produces calcium oxide (quick lime) powder and carbon dioxide gas. A chemist performed this reaction in a lab and found that the mass of the calcium oxide (quick lime) was less than the mass of the calcium carbonate. What is the reason behind this decrease in mass?
A. Carbon dioxide is produced, and as a gas, it was not captured to measure its mass.
In a chemical reaction, atoms are rearranged to form new molecules. However, atoms are neither created nor destroyed.
What happens to the total mass of the atoms involved in a chemical reaction?
B. It will stay the same no matter how the atoms are rearranged.
What group is entirely unicellular?
C. prokaryotes
While playing soccer, Jim falls down and scrapes his knee. Which form of cell division will result in the repair of the damaged skin tissue?
C. mitosis
Cystic fibrosis is a recessive genetic disorder caused by a mutation of the CTRF gene. The disease is characterized by excessive mucus production along the respiratory and digestive tracts in addition to other symptoms. Cystic fibrosis is a progressive disorder that is most associated with chronic respiratory disease.
Sara and Anthony found out that they are both carriers of the disorder, but neither have the disease. What are the chances their child will be born with cystic fibrosis?
D. 1:4
The egg cells of a dog have 39 chromosomes each. How many chromosomes does each of the dog's body cells have?
A. 78
Which of the following best describes a way in which the periodic table is organized?
D. Elements are organized into groups with similar properties.
A red blood cell has a round structure. A muscle cell has a long, thin structure. Which statement best explains why these two types of cells have different structures?
D. Each cell has a different function.
All living things need energy to perform their life processes. How and where do they get the energy that they need?
B. the oxidation of food through the process of cellular respiration
Which of the choices below is one of the primary gases found in the atmosphere?
B. oxygen
Which of these is the main difference between aerobic respiration and anaerobic respiration?
A. Anaerobic respiration does not require oxygen.