The graphs below show the relative concentrations of two gases in the air surrounding a group of mice.

Which process in the mice most likely accounts for the changes shown?

Cellular respiration can be expressed as the following equation:

Which of the following are cells formed by meiosis?

Analyze the graphic above. Which of the following statements accurately names and describes the function of the organelle labeled B?

In sexual reproduction, gametes are —

Meiosis is an essential part of sexual reproduction. This is because meiosis creates sex cells that have —

The diagram shows a process that can affect chromosomes during meiosis.

This process explains —

In cattle, the allele for short horns (S) is dominant over the allele for long horns (s). Two short-horn cows are bred and produce four offspring. Three have short horns and one has long horns. What are the most likely genotypes of the parents?

Blood type is controlled by inheriting any two of the following alleles: |^A, |^B, or II.

|^A codes for type A blood. |^B Codes for Type B blood. Both |^A and |^B are codominant. The I allele is recessive and will cause Type O blood whenever two copies of the allele are present.

If a mother has Type AB blood (|^A|^B) and a father has Type O blood (II), what percentage of their children are likely to have Type A blood?

A variety of corn can produce yellow or white seeds. Yellow is dominant. White is recessive. If an ear of corn contains only white corn, it must be —

Refer to the diagram. Arrange the stages in order.

In guinea pigs, the allele for rough coat (R) is dominant over the allele for smooth coat (r). A heterozygous guinea pig and a homozygous recessive guinea pig are mated. Which of the following would be the percentages of possible offspring phenotypes?

If a defective gene occurs on the X-chromosome, it will normally be transmitted to male offspring only by —

During prophase, chromosomes become visible, the spindle forms, and the nucleolus and nuclear envelope disappear. In which cellular process does prophase occur?

In certain rats, the allele for black fur is dominant over the allele for white fur. If two rats that are both heterozygous for fur color are mated several times, their offspring would be expected to have —

Delray has dimples and his wife does not. Delray has a homozygous dominant genotype for dimples, and his wife has a homozygous recessive genotype for no dimples. If Delray and his wife decide to have children, then which Punnett square correctly shows the probability of them having a child with dimples?

If single-celled organisms did not undergo the cell cycle, they could not —

The diagram illustrates the process of cell division.

What is the significance of anaphase in this process?

A student is investigating mitosis by examining detailed pictures of the process. The student wants to observe the formation of the nuclear envelope around the chromosomes. The student should focus on pictures of which phase of mitosis?

Which of the following will increase the rate at which carbon dioxide is being added to the Earth’s atmosphere?

A food chain contains oak trees (producer), mice (herbivore), black rat snakes (carnivore), and bald eagles (carnivore). If these organisms were placed in an energy pyramid, which organism would be in the energy level with the second-most amount of energy available?

Bacteria in soil converts nitrogen from the air and decaying biotic material into nitrates that are used by plants to produce protein. How does this process benefit the ecosystem?

The table below displays four events of mitosis in no particular order.

Which mitotic event in the table occurs after the other three events have taken place?

What is lost to the environment at each of the trophic levels of this ecosystem?

Which of the following describes what happens at the end of the M phase and before the G₁ phase of the cell cycle?

Which diagram best represents mitotic cell division?

Oxpeckers are birds that sit on zebras and rhinos and eat ticks and other parasites that live on their skin. The oxpeckers get food and, in return, the zebras and rhinos get pest control. When there is danger, the oxpeckers fly upward and scream a warning to help the zebras and rhinos.

Which of the following correctly identifies the symbiotic relationship between the oxpeckers and the zebras?

The amount of energy the producers, in this energy pyramid, provide the primary consumers is 54,000 joules. From this amount, 540 joules are provided to the tertiary consumers.

Based on this model, how much of the energy was provided to secondary consumers?

In any environment or ecosystem, organisms can have several different types of relationships.Three types of relationships are described below.

Which of these correctly describes the relationships between the organisms?

Enzymes are proteins that help increase the rate of chemical reactions inside cells. These proteins are composed of many simpler molecules called amino acids. Which of the following suggests that the shape of an enzyme determines the enzyme’s function?

The diagram shows a partial East Texas food web.

Which table correctly classifies these organisms?

Surtsey is an island located south of Iceland. The island was formed by a volcanic eruption and first appeared in 1963. The table below contains descriptions of changes in the population and diversity of species on Surtsey.

Which of these lists the descriptions in the correct order of ecological succession on Surtsey?

How does the cell membrane help maintain homeostasis for the cell?

In 1960, scientists discovered a molecule that was used to carry genetic information in the nucleus to ribosomes. This information is used to make proteins that are used to perform various functions for an organism. Which biomolecule is used to transmit genetic information?

Enchanted Rock State Natural Area is located in Central Texas. Enchanted Rock is a dome of granite. The area contains four easily identifiable communities. The table describes characteristics of each type of community in the area.

A student studying primary succession should focus on which of these communities?

Diffusion and osmosis are both vital to cell function. Diffusion and osmosis are similar in that they are both types of –

Carbohydrates and lipids both serve as a source of energy for organisms. What kind(s) of energy are provided by carbohydrates and lipids?

The graphs show the reaction rate for an enzyme across a range of temperatures and pH.

Based on these data, this enzyme functions best at what temperature and pH?

One of the main functions of the semi-permeable cell membrane is to maintain homeostasis for the cell. Semi-permeable means that only some molecules are allowed to cross the membrane and others are not. What molecule enables large molecules to cross the membrane?

Which group of organelles is directly responsible for the production of new molecules within a cell?

Two biomolecules are shown.

Which of the following best describes these biomolecules?

A model of the cell membrane shows many different molecules that perform various functions for the cell.

Some of these molecules keep the contents inside of the cell separated from the contents outside of the cell. Others allow certain materials to be transported across the membrane. A few provide signals that can alter cell behavior, and some provide stability for the membrane.

Which molecule separates the contents inside of the cell from the contents outside of the cell?

Which of the following describes osmosis?

A few drops of Lugol's iodine solution placed in a beaker of water will turn the water red. A starch solution was poured into a length of dialysis tubing, and the ends were tied. The starch solution was white. The tubing was then dropped into the beaker of iodine solution. After 10 minutes, the white starch solution turned black, and the iodine water remained red.

If the dialysis tubing represents a cell membrane in this demonstration, what process is being observed in the changing color of the starch solution?

Students are discussing what they know about cellular transport. Their explanations are displayed in the table.

Which student(s) gave an accurate statement regarding cellular transport?

A scientist observes two cells. Cell 1 and Cell 2 both contain DNA (genetic material) and ribosomes. However, Cell 1 contains a nucleus and other membrane-bound organelles, which Cell 2 does not.

What is the correct classification for each of the cells?