The Proccess of Photosynthesis

Plants need sunlight. Houseplants lean toward the Sun, and if they do not get enough light they wither and die. Plants use sunlight to make their food. This process is called photosynthesis.

 Photosynthesis is a scientific word made up from Greek words. These words mean “putting things together using light.” Inside plants’ leaves, light causes air and water to combine to make new chemicals. These chemicals are food for the plants.

DNA, Genes, and Heredity

Have you ever heard a news reporter talk about DNA? Reporters talk about DNA found at the scene of a crime. They talk about police finding DNA “fingerprints.” Police sometimes use DNA as a clue to find out who committed the crime.

DNA (deoxyribonucleic acid) is a substance that makes up genes. Everything alive has genes. Plants have genes. Animals have genes. You have genes.

Gregor Mendel

Gregor Mendel (1822-1884), Austrian monk, whose experimental work became the basis of modern hereditary theory.

Mendel was born on July 22, 1822, to a peasant family in Heinzendorf (now Hynčice, Czech Republic). He entered the Augustinian monastery at Brünn (now Brno, Czech Republic), which was known as a center of learning and scientific endeavor. He later became a substitute teacher at the technical school in Brünn. There Mendel became actively engaged in investigating variation, heredity, and evolution in plants at the monastery's experimental garden. Between 1856 and 1863 he cultivated and tested at least 28,000 pea plants, carefully analyzing seven pairs of seed and plant characteristics. His tedious experiments resulted in the enunciation of two generalizations that later became known as the laws of heredity. His observations also led him to coin two terms still used in present-day genetics: dominance, for a trait that shows up in an offspring; and recessiveness, for a trait masked by a dominant gene.

The Water Cycle (Rain Cycle)

Maybe you recycle cans, glass, and paper. Did you know that nature recycles, too? One of the things nature recycles is water. Water goes from the ocean, lakes, and rivers into the air. Water falls from the air as rain or snow. Rain or snow eventually find their way back to the ocean. Nature’s recycling program for water is called the water cycle.

The water cycle has four stages: storage, evaporation, precipitation, and runoff. Most of the water on Earth is in the first stage, storage. Water on Earth gets stored in oceans, lakes, rivers, ice, and even underground. The oceans store the majority of this water.

Napoleon Bonaparte: A hero in France

The French called Napoleon Bonaparte “a man of destiny.” A hero in France, Napoleon was hated elsewhere in Europe. Today, Napoleon is remembered as one of the greatest military leaders of all time. He built an empire that covered much of Europe.

Napoleon Bonaparte was born in 1769 on Corsica, an island in the Mediterranean Sea. At the age of 16, Napoleon chose a career in the French army.

In 1789, a revolution began that rocked France. The king and queen were executed. Hungry working people demanded new freedoms. Revolutionary governments in France swept away old laws. They declared war on supporters of the former king. The French Revolution lasted until 1799.