Question

Which of the plants listed below is heterotrophic (has to obtain organic food from the environment)? a. a green houseplant b. a legume plant such as bean c. a carnivorous plant such as the sundew d. ghostly white Monotropa e. none of the above

Short answer

The correct answer is (d) Ghostly white Monotropa.

Step-by-step solution

Identifying Heterotrophic Organisms

Recognize that heterotrophic organisms are those who are mainly dependent on other living organisms or dead organic material for their nutrition. They are incapable of photosynthesis and need to obtain food and energy from organic substances.

Review the Choices

Review the given options: (a) A green houseplant, (b) A legume plant such as a bean, (c) A carnivorous plant such as the sundew, (d) Ghostly white Monotropa, and (e) None of the above. The first three are capable of photosynthesis so they are autotrophic. Autotrophs can utilize solar energy or chemical energy to generate their food materials.

Select the Appropriate Option

Among the options, ghostly white Monotropa (option d) is heterotrophic. This plant lacks chlorophyll and cannot do photosynthesis, therefore it must obtain organic food from the environment. So, the correct choice is (d) Ghostly white Monotropa.

Key concepts

Monotropa

Monotropa, also known as "Indian Pipe" or "Ghost Plant," stands out because of its unique way of life among plants. Unlike typical green plants, Monotropa lacks chlorophyll. Chlorophyll is the pigment responsible for capturing sunlight for photosynthesis. As a result, Monotropa appears white or ghostly, which is why it’s sometimes called the "ghostly white Monotropa."

As it cannot photosynthesize, Monotropa is heterotrophic. This means that it relies on organic materials in its environment for nutrition. More specifically, Monotropa engages in a symbiotic relationship with fungi. This relationship is known as mycoheterotrophy.

Through this connection, Monotropa indirectly obtains nutrients from trees. The fungi connect to tree roots, derive nutrients, and share them with Monotropa. This fascinating method of nutrient acquisition allows Monotropa to thrive in dark forest understories where light is scarce.

photosynthesis

Photosynthesis is the process that enables green plants to make their food using sunlight, water, and carbon dioxide. This process occurs in the chloroplasts of plant cells, which contain chlorophyll. The main function of chlorophyll is to capture light energy.

During photosynthesis, light energy is converted into chemical energy in the form of glucose. Oxygen is released as a byproduct, which is vital for the survival of many organisms on Earth. The chemical equation representing photosynthesis is:

• \[6CO_2 + 6H_2O + light ext{ energy} \rightarrow C_6H_{12}O_6 + 6O_2\]

Autotrophic plants perform photosynthesis, making their food and giving them independence from other organisms for nutrition. However, some unique plants like Monotropa cannot perform photosynthesis and thus rely on alternative means to obtain nutrients.

autotrophs

Autotrophs, often referred to as "self-feeders," are organisms capable of producing their own food. They do this through processes like photosynthesis, using sunlight, or chemosynthesis, using chemical reactions. These organisms form the base of the food chain and are crucial for the survival of most life on Earth.

Green plants, algae, and some bacteria are common examples of autotrophs. They utilize sunlight energy to transform water and carbon dioxide into glucose and oxygen — a process essential for life.

Autotrophs differ from heterotrophs in that they do not rely on external organic material for their food. This capability allows them to thrive in diverse environments from deep oceans to high mountains. Unfortunately, not all plants can photosynthesize, like Monotropa, which lack the necessary chlorophyll pigment.

carnivorous plants

Carnivorous plants represent a unique adaptation among autotrophs. Although they can perform photosynthesis to produce food, these plants have also evolved mechanisms to capture and digest insects and small animals. This adaptation is particularly beneficial in nutrient-poor environments, such as bogs or acidic wetlands, where they often reside.

Examples of carnivorous plants include the Venus Flytrap, pitcher plants, and sundews. Sundews, for instance, have sticky glandular hairs on their leaves that trap unsuspecting insects. Once an insect is caught, the plant secretes digestive enzymes to obtain nutrients from its prey.

While carnivorous plants are primarily autotrophic due to their ability to photosynthesize, their supplementary food-gathering strategy provides an essential nutrient source that aids in their survival in less-than-ideal growing conditions.