certain substances are place in the beaker in the given picture if the Gravel of sand and Drop of sunflower oil fill in the beaker then state what condition it Remain.
Answers
Answer:
After completing the activities in this lesson, help youth reflect on what they
have learned with these questions:
What do plants need in order to grow?
sunlight, water, air, proper temperature, nutrients
What is photosynthesis?
food manufacturing process in green plants
How do plants get their water and nutrients?
absorption by the roots
Why is water important to plant growth?
used in photosynthesis, transports nutrients, regulates
temperature, keeps cells turgid
What are some ways plants adapt to their environments?
hard seed coats, chemical defense, thorns and spines
Why do plants need space and shelter?
overcrowded areas increase competition for growth limiting
growth factors
young plants need shelter from harsh environmental
conditions
APPLY
Help youth learn to apply what they have learned.
Name the limiting factors that effect plant growth.
Investigate how the structure and shape of a leaf affects photosynthesis.
Start a compost pile!!! Follow the instructions on the COMPOSTING
information sheet.
Find out what adaption desert plants have developed to minimize water
loss.
Collect and identify seeds around your schoolyard. How was each seed
dispersed? What are it’s chances of survival?
Inspect an artificial habitat (vegetable garden, lawn, hedgerow). Discuss
what the plants need and how those needs are met.
Plant Connections, Lesson 3
Introduction
BACKGROUND BASICS ... What Makes Plants Grow?
The vital needs of a plant are very much like our own - light, water, air, nutrients, and a proper
temperature. The relative importance of each of these needs differs widely among plants. The ability
of a plant species to spread throughout a geographic area is a direct result of its adaption to the abiotic
and biotic components of the area. Although most habitat components act on a plant simultaneously
and should be considered together, the lack of one essential component can determine the health of a
plant. This factor, whatever it may be, is referred to as a limiting factor. The concept of limiting factors
applies to all aspects of a plant's interaction with its habitat. Any factor in the ecosystem can act as a
limiting factor. For example, water is important to many species; most species cannot live in desert
regions because of lack of water and most cannot live in marshes because of excess water. Extreme
temperatures inhibit plant growth in many regions; lack of warmth in winter is a limiting factor that
keeps many species restricted to the tropics.
Another limiting factor is often competition from species that use the same resources.
Competition is the principal interaction among plants. Plants of the same species are strongly
competitive because they have the same requirements for sunlight, water, and nutrients.
Environmental Factors Affecting Plant Growth
Light
Light reaching the surface of a plant is either absorbed, reflected, or transmitted. Energy, in the
form of sunlight is one of the driving forces in the chemical reaction known as photosynthesis.
Photosynthesis is the process by which green plants manufacture food, mainly sugars, from carbon
dioxide and water in the presence of chlorophyll (a green pigment), utilizing light energy and releasing
oxygen and water. Together the quality, quantity, and duration of light influences plant growth. Plants
grown in direct sunlight are typically compact, where as those in shade are taller and elongated. Seeds
may start to grow (germinate) without light, but the plant growing from it must have light if it is to
continue to grow.
Moisture
Water is essential for life, it is one of the most important requirements for plant growth. Water
is the main component in plants cells, it keeps the plant turgid (stiff), it is used in photosynthesis, and
transports nutrients throughout the plant. Plants also use water to lower leaf temperature, increase
mineral absorption, and pull water from the roots to the top of the plants through a process known as
transpiration.
The hydrologic cycle. The hydrologic cycle is the cycle of water in the environment. Water
moves in a series of processes. Water moves by precipitation, evaporation, transpiration, and
condensation. The sun provides the energy for water to move in a cycle. All water on earth is part of
the water cycle regardless if it is in a lake, our bodies, food, or underground. Precipitation (rain, snow,
hail, etc.) either infiltrates the soil or runs into nearby ditches or streams. Water on the surface of a lake
or pool will eventually evaporate from the sun’s heat and become water vapor. This vapor then
becomes part of a cloud and condenses to form precipitation. Plants release water vapor into the
atmosphere by transpiration.