Wild hogs introduced to Texas from Europe became feral after the hogs escaped from the ranches where they lived. Feral hogs are omnivores that feed on native plants, crops, and small animals. Feral hogs can damage an ecosystem by rooting through the soil to look for food and trampling small plants. Which types of native organisms do feral hogs most likely compete with for food sources?

Based on the description given, feral hogs eat both plants and animals making the compete with both herbivores and carnivores.

The strangler fig is a vine that starts out as a seed in the tree canopy of the rain forest. It drops its roots down from the canopy to the forest floor.

By sprouting in the rain-forest canopy, the strangler fig is exposed to more--

Since the sprouting happened in a canopy it gave it more exposure to sunlight.

Giant salvinia is an aquatic plant that floats on water and reproduces rapidly. When these plants die, decomposition by bacteria affects oxygen levels in the water. As more plants die, less oxygen is available in the water. Students observe a pond covered by giant salvinia.

Which statement is the best prediction the students can make about the immediate future of the pond?

Fish also need oxygen to survive. They get their oxygen in a form of a gas dissolved in water. If this salvina affects oxygen level in water then the fish population will decrease.

Plants grow in many different shapes and sizes. Much of their shape depends on an internal structure that is composed of carbon-containing molecules such as cellulose and lignin. Plants that have a strong internal structure can grow larger than other plants because their structure can support their size.

Plants obtain the majority of the carbon necessary for building these structural molecules from.

Plants absorbs carbon dioxide from air to form those carbon-containing molecules.

Black walnut trees produce a nontoxic chemical that becomes highly toxic when it is exposed to air or soil. How does this chemical help black walnut trees compete with plants growing nearby?

This is a strategy that the black walnut tree uses for competition. They can intoxicate the other plants for them to not grow.

Whitetip reef sharks spend most of the day lying on the ocean floor. While remaining still, these sharks pump water across their gills.

The movement of water across their gills is necessary for-

The movement of water transports oxygen to the shark while they are remaining still in the bottom of the ocean. Sharks use their gills to breathe.

The Couch's spadefoot is adapted to a certain type of environment. Which of these resources is most likely scarce in this environment?

They lay their eggs in temporary pods formed from rain. Water is not seen much in their environment since they are mostly under soil.

Which organisms in the food web shown above compete for the same food source in this environment?

Frogs and Snakes both eat Grasshoppers. Remember to always look for your producer and follow the energy flow arrows from that point going up.

At which temperature range will there be the most competition for space among these fish species?

It will be 25⁰C to 30⁰C because in that temperature there are 3 different fish species competing for space.

Which pair of organisms represents a predator/prey relationship?

Tuna and squid are the only predator/prey relationships in the options given.