Which of the following processes allows the cells of an organism to use carbon from the environment?
Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.
During photosynthesis in plants, what is the source of the carbon in the sugar molecule (C6H12O6)?
Carbon dioxide is used from the air during photosynthesis.
Change of phase is a process whereby matter changes form (solid, liquid, gas).Which one of the following constitutes a phase change?
Since the wax melts because the temperature of the wax is raised, once the heat source is removed, the wax will begin to lose heat, assuming that ambient temperature is low enough. Eventually, the wax will go through another phase change and become solid. So, the short answer is: burning is irreversible because it involves a chemical reaction, while melting is reversible because it's just a phase change.
Newton’s laws of motion provides that an object set in motion remains in motion unless a force acts on it. If you suspend a ball from a tree with a piece of string and make it swing, the ball will swing for a while, then slow down and stop.Why does the ball stop swinging?
The ball in motion slows down and stops swinging because the force of friction acts on it. The kinetic energy of the object is converted to heat energy through friction with air.
Which of the following are true about gravity? Select all that apply
The gravitational force between two objects depends on the masses of both objects not just one of the objects. Both B and D imply that only one object determines the gravitational force.
Two positvely charged objects
A positively charged object will exert a repulsive force upon a second positively charged object. This repulsive force will push the two objects apart. Similarly, a negatively charged object will exert a repulsive force upon a second negatively charged object. Objects with like charge repel each other.
The diagram above shows a geologic cross section.
Which rock layer most likely contains fossils of the oldest evolved organisms?
With geological cross sections, the most recent organisms are on top and the oldest organisms would appear on bottom.
Which of the following structures is not found in bacteria?
At one time it was thought that bacteria were essentially "bags of enzymes" with no inherent cellular architecture. The development of the electron microscope in the 1950s revealed the distinct anatomical features of bacteria and confirmed the suspicion that they lacked a nuclear membrane. Structurally, a bacterial cell has three architectural regions: appendages (attachments to the cell surface) in the form of flagella and pili (or fimbriae); a cell envelope consisting of a capsule, cell wall and plasma membrane; and a cytoplasmic region that contains the cell chromosome (DNA) and ribosomes and various sorts of inclusions. In this lecture, we will discuss the anatomical structures of procaryotic cells in relation to their adaptation, function and behavior in natural environments.
What always stays the same when a chemical reaction takes place?
The number of atoms stays constant throughout a chemical reaction.
In the winter, people like to wear coats. Why is this?
Coats provide insulation by reducing the amount of heat lost from the body.
Which of the following is NOT true?
Animal cells usually don’t have a cell wall. Other statements are true.
The polar bear's dense fur and an exceptionally thick layer of fat under its skin protect it against the freezing temperatures of the habitat.
Natural Selection is the process whereby organisms better adapted to their environment tend to survive and produce more offspring. The theory of its action was first fully expounded by Charles Darwin and is now believed to be the main process that brings about evolution. In this case, polar bears with thicker fur were able to better survive in their environment while thinner furred polar bears died off over time.
Which of the following is a source of genetic variation within a species?
Mutation is the changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations.
Rainfall in a tropical region is below average for 20 consecutive years. Animals adapted for dry conditions are much more plentiful at the end of the 20 years. Which of the following statements best explains the increase in the population of these animals?
Natural Selection is the process whereby organisms better adapted to their environment tend to survive and produce more offspring.