Video Transcript
Having support structures within a plant allows it to maintain a strong stem. Which of the following is not a direct advantage of a plant having a strong stem? (A) The plant can grow taller and therefore take in more light for photosynthesis. (B) The plant can withstand strong winds and other environmental pressures. (C) The plant can grow and support branches, leaves, and flowers. Or (D) the plant can absorb more mineral ions from the surrounding atmosphere.
To answer this question, we need to know some of the advantages of a plant having a strong stem, so let’s dive right in. Most plants use a process called photosynthesis to make their own food in the form of glucose from simple inorganic molecules. The prefix photo- in photosynthesis tells us that this process requires light. Having a strong stem allows plants to grow taller. This usually allows them to access more light in their photosynthesizing cells, the majority of which are found in their leaves. This is because the light source is usually the Sun, and it tends to be in an upward direction.
In fact, tall plants usually have a competitive edge over their neighbors, which are shaded by these taller plants, especially in dense forests. This allows the taller plants to absorb more sunlight than their shaded counterparts to increase their rate of photosynthesis, make more food, and as a result have more energy to grow even further, while the plants that do not absorb enough sunlight may eventually die. As the question is asking us for an answer that is not a direct advantage of a plant having a strong stem, we can eliminate option (A), as growing taller does allow a plant to take in more light for photosynthesis.
Have you ever seen a broken tree after a fierce storm? This shows that even the toughest of stems are vulnerable to breaking against the challenging conditions like strong winds and their environments. Having a strong stem allows plants to withstand these environmental pressures to survive and thrive compared to weaker stemmed plants. This tells us that option (B) is also incorrect, as a strong stem does help a plant withstand strong winds and other environmental pressures.
Some plant parts add significant weight that the stem needs to hold up. For example, while some flowers and leaves can be pretty light, when there are a lot of them or the stem also needs to support fruit and the heavy branches that sometimes hold these organs, it can weigh a lot. Having a strong stem allows plants to grow these helpful plant organs, while weaker stems might bend or even buckle under the mass. The stem supporting certain flowers can be very long. For example, each flower of the aptly named Allium giganteum plant can be up to 15 centimeters in diameter. And each is supported by one very long stem of up to 1.5 meters in height. Strong support mechanisms definitely need to be in place in the stem to support these huge flowers and allow them to carry out their function. We’ve deduced that option (C) cannot be the correct answer, as a strong stem does help to support branches, flowers, and other plant parts.
Plants absorb mineral ions into their roots, usually from soil. From the roots, these minerals can be transported through the plant stem to all the plant organs that require them. However, the stem itself is not responsible for absorbing mineral ions, nor are these ions usually absorbed from the atmosphere, but instead from the soil and into the roots. Therefore, we’ve worked out the correct answer to the question. The statement that is not describing a direct advantage of a plant having a strong stem is (D), so the plant can absorb more mineral ions from the surrounding atmosphere.
