Types of Experiments: Control experiment
There is a type of experiment in which a scientist uses a control variable approach. All conditions in the experiment will be the same except for one variable. When testing water tolerance of barley plants, for example, you could not water one plant, over-water one plant, under-water another plant, and water the last plant with the optimal amount of water and observe the results.
Understanding reproduction by comparing that of plants and animals
The way plants and animals reproduce may seem complicated and very different from each other. However, when you break down plant and animal reproduction by reproductive structures and cells, they are very similar.
Wheat field
Wheat is a plant that produces a type of grain. This grain can be used to grow more wheat plants. The grain can be ground up into flour and is used in many food items.
White leafy seadragon
This seadragon is white with a light pattern. It has a snout (right end) and the back end is to the left. Seadragons can't hold onto sea plants like seahorses can. It has some fins along its back that it uses to propel itself and move around in the water. The leafy parts are only used to blend in and ...
White's seahorse
Seahorses can use their tails to hang onto plants around them. Seahorses can also swim, but hang onto sea plants when they want to rest or when there is a strong ocean current.
Wild cucumber plant at Tucker Wildlife Center.
This plant is likely exposed to direct sunlight during most of the day. "Sun" leaves are generally thicker than the leaves of plants from shady areas.
Wilted plant
Although this muskmelon plant has wilted from a bacterial infection, plants can wilt for other reasons and look just like this one. Plants can be over-watered and under-watered. Plants have a range of tolerance in which they can grow. Plants also have an optimum amount of water they can receive and ...
Young corn plants
These corn plants grew from small corn kernels. They have many green leaves so they can absorb sunlight and make food to grow. These plants will later produce ears of corn.
Young green plants in forest
These young plants grew from small seedlings after they sprouted from a seed. They have several green leaves to collect sunlight.
Yucca plant in the Mojave desert
Yucca plants use an alternative form of photosynthesis that allows them to conserve water. This is an adaptation to the dry desert environment.
Zebrafish embryo development
Early development of Danio eggs – note the internal structure and the cluster of eggs (note the large yolk attached to the two-cell egg). The cells all divide at the same time. Within two days this mass of dividing cells will take on the shape of a zebrafish larvae.
Zebrafish fertilized egg
Developing 8-cell stage attached to a large yolk sac of Danio.
Hands-on Experiments To Test for Acid Mine Drainage
This is an on-line prototype for a book aimed at teaching kids the effects of acid mine drainage on our environment through experimentation and observation. Experiments introduce litmus paper, pH testing, neutralization, identification of aquatic organisms and their use as water quality indicators, acid mine drainage, organisms in acidic environments (including plants, bacteria, and algae), oxidation-reduction reactions, the manganese cycle, the water cycle, and treatments for acid mine drainage
Risk Assessment for Toxic Air Pollutants: A Citizen's Guide
This EPA fact sheet provides easy-to-understand information about air pollution and how it affects human health. Topics include health risks, exposure assessment, dose-response relationships, risk assessment, and risk characterization. Simple diagrams and pictures support the text.
National Middle School Science and Technology Bowl
Two competitions: an academic competition in which middle school students answer fast-paced questions about math and science (earth, physical, life, and general science) and a model fuel cell car competition that challenges students to design, build, and race model cars.
Histology
Although a great deal of emphasis of the course is on the structures of the organs and tissues, this is not a course based solely on pure microscopic descriptions. Lectures and laboratory sessions will focus on the integration of structures with functions, drawing from many disciplines (light/electron microscopy, cell biology, biochemistry, physiology etc.). Highlights of the course are its magnificently detailed collections of tissues as represented in the Circulatory Lecture.
Mitochondria
Often referred to as the powerhouses of the cell, mitochondria provide the energy that powers nearly every cellular process. This essay by John Ross describes in detail the structures and functions of these amazing organelles.
Engineering for the Earth
Young students are introduced to the complex systems of the Earth through numerous lessons on the Earth's natural resources, processes, weather, climate and landforms. Key earth science topics include rocks, soils and minerals, water and natural resources, weather patterns and climatic regions, wind, erosion, landforms, and the harvesting of fossil fuels all presented from an engineering point-of-view. (See the Unit Overview section for a list of topics by lesson.) Through many hands-on activiti
The Growling Stomach
In this lesson, the students will investigate what types of plants and insects they could eat to survive in the Amazon. They will research various plants and/or insects and identify characteristics that make them edible or useful for the trip. The students will create posters and present their findings to the class.
Cells
In this unit, students look at the components of cells and their functions and discover the controversy behind stem cell research. The first lesson focuses on the difference between prokaryotic and eukaryotic cells. In the second lesson, students learn about the basics of cellular respiration. They ...
