A food web is shown.

Removal of which species would have the greatest impact on the survival of the snake population?

The diagram shows a process that occurs during the development of an organism.

Which statement explains how the different cell types in the image are formed?

Kelp forests are critical ecosystems that provide habitats to a variety of animals, including sea urchins, sea stars, sea anemones, crabs, jellyfish, snails, and fish. They also provide hunting grounds for mammals, including sea otters, sea lions, seals and many different birds. In recent years scientists have documented an increase in shark attacks on sea otters in and around kelp forests.

Which consequence is most likely to occur in kelp forests as a result of increased predation of sea otters?

Which plant response would best aid a plant in maximizing and retaining water acquired during a drought?

The salamanders of the genus Ambystoma in northeastern North America are an entirely female population that reproduces asexually through the process of cloning. However, they have developed a way of inserting DNA from other species of salamanders into their own DNA.

How has DNA from other salamander species helped these Ambystoma salamanders survive environmental changes over the past 6 million years?

The feedback loop for blood calcium homeostasis is shown.

According to the diagram, which four body systems are interacting to maintain blood calcium homeostasis?

When sawdust is added to soil, organisms in the soil will use all the available nitrogen to break the sawdust down. What effect will the lack of nitrogen have on the plants that are near the sawdust?

A cell undergoing a biological process is shown.

Which process occurs between Step 2 and Step 3 and creates more genetic diversity in the resulting cells?

Certain species of the coral-like sea organisms called bryozoans first appeared about 140 million years ago. They remained unchanged for the first 40 million years and then suddenly experienced rapid genetic change.

Which process would BEST account for the pattern of evolution of bryozoans?

Spores of the fungus Ustilago maydis land and grown on sweet corn. The fungus then infects the plant tissue, extracting nutrients from the plant's cells.

The relationship between sweet corn and Ustilago maydis can best be described as -

During early stages of development, dolphin embryos begin to develop hind limbs. By the time dolphin fetuses are fully developed, the hind limbs have disappeared.

Which statement best describes the early development and then disappearance of the hind limbs in dolphins?

The Florida panther (Puma concolor coryi) population had declined to approximately 20 to 30 individuals as a result of habitat loss and hunting. Many of the panthers had genetic mutations due to inbreeding that affected their ability to reproduce and survive. Female Texas (Puma concolor stanleyana) pumas were introduced into Florida to mate with the endangered population of panthers. Hybrid panthers had more genetic variation and reproductive success than the Florida panthers.

Which table best represents the mechanism of evolution and the effect on the gene pool of the Florida population?

The temperature at which American alligator eggs are incubated will affect the gender of the offspring. Eggs kept at 30^oC tend to hatch mostly female, while eggs kept at 33^oF tend to hatch mostly male.

Which statement explains why the temperature affects the gender of the alligator hatchlings?

A food chain is shown.

Which model best represents the amount of energy available for the use of each trophic level represented in the food chain?

The diagram shows molecules that a mitochondrion uses and produces during a cellular process.

Hippos interact with oxpeckers, ticks, and crocodiles. Ticks suck the blood from the Hippos. Oxpeckers live on the backs of Hippos and feed on the Ticks found on the Hippos skin. Crocodiles are carnivores that prey on hippos living in the same environment.

Which list describes the types of relationships the Hippo has with the other organisms?

Trophy hunting is causing a decline in animal populations in the Savannah, such as the Rhino. Rhino are being hunted faster than they can reproduce.

Which statement describes the most likely effect that trophy hunting will have on this ecosystem?

Climate change (Global Warming), is primarily a problem of having too much carbon dioxide in the atmosphere. Burning coal, gasoline, and oil releases carbon dioxide (CO₂) into the atmosphere.

Which process removes carbon dioxide (CO₂) from the atmosphere?

Natural selection is based on the idea that adaptations will increase the fitness of an organism.

Which of the following terms would BEST describes what it means to be “fit”?

Select TWO correct answers:

Clownfish (Amphiprion ocellaris) live within sea anemones in warm bodies of water. The table contains some information about this fish.

Why does the ability to lay 100 to 1,500 eggs every 10 to 14 days increase the fitness of the species Amphiprion ocellaris?

A zoologist recorded the following information regarding breeding habits of the Kiwi bird:

The Great Spotted Kiwi can only lay a single egg once per year. While the female Kiwi reproductive cycle lasts from July through February, breeding season (when Kiwis lay their egg) is typically in January. The male kiwi then incubates the egg until it hatches in April or May.

Based on the information in the charts, what is the most likely explanation for the Great Spotted Kiwi to lay their eggs in January instead of any other month?

In the southeastern United States, coral snakes exhibit a distinctive pattern of red, yellow, and black banding, which closely resembles the appearance of scarlet snakes. Coral snakes are venomous, and most predators avoid them to reduce the risk of being bitten.

Which of the following BEST explains how the scarlet king snake benefits from looking like the Eastern coral snake?

Below is a diagram of a phylogenetic tree on DNA similarities of five organisms.

Which lettered location on the phylogenetic tree identifies characteristics shared by species X, Y and Z?

Based on the diagram of the forest ecosystem, which statement is true?

Which evidence supports the answer from the previous question?