Back to: Botany 100 Level
Hello, my brilliant Afrilearn scholar! I hope you’re doing great today! Have you ever wondered how plants breathe, drink water, and grow even though they don’t move like animals? Just like humans need air, food, and water to survive, plants also carry out important life processes to stay alive. These processes are part of plant physiology—the study of how plants function.
Today, we’ll be learning about the key processes that keep plants alive, including photosynthesis, respiration, transpiration, and nutrient transport. By the end of this lesson, you’ll understand how plants take in water, make their food, and release oxygen into the air!
Plant Physiology: The Processes Of Life
Key Processes of Life in Plants
Plants carry out several important processes that help them grow, survive, and reproduce. These include:
Photosynthesis – How Plants Make Their Food
This is the process by which plants use sunlight, carbon dioxide, and water to produce glucose (food) and oxygen.
It takes place in the chloroplasts of the leaves, which contain chlorophyll (the green pigment that captures sunlight).
Equation: Carbon dioxide + Water + Sunlight → Glucose + Oxygen
Without photosynthesis, plants wouldn’t have food, and humans wouldn’t have oxygen!
Respiration – How Plants Get Energy
Just like humans breathe, plants also break down glucose to release energy.
This happens through a process called cellular respiration, which takes place in the mitochondria of plant cells.
Plants take in oxygen and break down glucose, releasing energy, carbon dioxide, and water.
This energy is used for growth, reproduction, and movement of substances inside the plant.
Equation: Glucose + Oxygen → Energy + Carbon dioxide + Water
Transpiration – How Plants Lose Water
This is the process by which water evaporates from the leaves through tiny pores called stomata.
It helps the plant cool down and pull more water and nutrients from the roots.
Transpiration is like sweating in humans—it prevents the plant from overheating.
Transport of Water and Nutrients
Water and minerals absorbed by the roots are transported to the leaves through the xylem.
Food (glucose) made in the leaves is transported to other parts of the plant through the phloem.
This movement of substances ensures that all parts of the plant get the nutrients they need to function properly.
Growth and Development
Plants grow through cell division in special tissues called meristems (found in roots and shoots).
Growth is controlled by plant hormones, such as auxins, which help the stem bend toward light.
Plant Responses (Tropisms)
Plants respond to their environment in different ways:
Phototropism – Growing toward light (e.g., sunflower turning towards the sun).
Gravitropism – Roots grow downward due to gravity, while stems grow upward.
Thigmotropism – Plants respond to touch (e.g., vines wrapping around a support).
Why Are These Processes Important?
Each of these processes is vital for a plant’s survival:
Photosynthesis provides food.
Respiration releases energy.
Transpiration helps in cooling and water movement.
Transport ensures all parts of the plant get nutrients.
Growth and development allow plants to reproduce and adapt.
Responses (tropisms) help plants adjust to their environment.
Without these processes, plants would wither and die, affecting the entire food chain—including humans!
Summary
Plant physiology is the study of how plants function.
Photosynthesis allows plants to make their food using sunlight.
Respiration breaks down food to release energy.
Transpiration helps plants cool down and absorb water.
Xylem transports water and minerals, while phloem transports food.
Plants grow and respond to their environment through hormones and tropisms.
Evaluation
- What is photosynthesis, and why is it important?
- How does respiration differ from photosynthesis?
- What is transpiration, and why do plants need it?
- Explain how water moves from the roots to the leaves.
- Give two examples of plant responses to the environment.
You are doing an amazing job! Plants may not move like animals, but they are always working behind the scenes to stay alive and keep our planet green! Keep learning, keep growing, and see you in the next exciting lesson!
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