Learning about Heredity

In this topic I learn about how characteristics are passed from parent to offspring.
 
A characteristic that is passed from parent to offspring is called an inherited trait. In corn, inherited traits include kernel color, plant height, and ear size. Heredity is the passing of these traits from one generation to the next. The word generation refers to parents and offspring. Hair color, eye color, and dimples are examples of human inherited traits.
The study of how heredity works is called genetics. Gregor Mendel was the first person to count the numbers and types of offspring of pea plants to measure the inheritance of specific traits. He is now considered the father of genetics.
Mendel studied the pollination of pea plants. Pollination is the transfer of pollen from the male part of a flower to the female part. As a result of pollination, a cell is formed that develops into a seed.
In one experiment, Mendel cross-pollinated purebred tall peas with purebred short peas. Cross-pollination takes place when pollen from one flower is transported to a different flower. All of the offspring resulting from the cross were tall. The offspring were hybrids. A hybrid is an organism produced by crossing parents that have two different forms of the same trait. Mendel concluded that each tall hybrid in the first offspring generation carried both tall and short traits. He called tallness the dominant trait. A dominant trait is the form of a trait that appears in the hybrid generation. He called shortness the recessive trait. A recessive trait is a form of a trait that is hidden, or masked, in the hybrid generation.
This is how heredity works.
   

Geologic Time

In this topic I learn about how the history of Earth is studied.
One way of finding the age of sedimentary rocks is called superposition. Superposition means that in a series of rock layers the bottom layer is the oldest and the top layer is the youngest. Using this idea, scientists are able to determine the relative age of a rock. The age of a rock compared with another rock is called the relative age of a rock. In a given place, they can tell which layers are older than others.
 By comparing rock layers from around Earth, scientists have put together a geologic column. This is a listing of Earth's rock layers in order from oldest to youngest. It is miles thick. 
Fossils are often found inside the rock layers. A fossil is any trace, imprint, or remains of a living thing preserved in Earth's crust. Fossils provide clues to a rock's relative age. A number of fossils called index fossils are the remains of living things that were widespread but only lived for a short part of Earth's history.  Many rocks contain radioactive elements. Certain radioactive elements break apart, or decay, into other elements. This happens at a constant rate which is now known. The rate is called half-life. Half-life is the time it takes for half the mass of an original element to change into a new product, the decay product.
By comparing the amount of original element to the amount of decay product, we can determine how long this process has been going on. This is how scientists tell the absolute age of a rock. The absolute age is the age of a rock in years.
Scientists are able to assign actual ages to the rocks in the geologic column. Scientists use these ages to put together a history of Earth. One of the long stretches of time that Earth's history is divided into is called an era. We now live in the Cenozoic era, which began about 70 million years ago.
And This is what I know about Geologic Time .
 

The Rock Cycle

In this topic I learn about different types of rocks.
Rocks are solids that make up Earth's crust. Rocks contain minerals. A mineral is a naturally occurring solid in Earth's crust with a definite structure and composition. Each mineral is made up of particular elements.
A rock can be one mineral or a mixture of minerals.  Properties include hardness, luster, and streak. A way to identify rocks is by identifying the minerals it contains. A rock gets its properties from the way it forms. Rocks form from several basic processes. They are grouped into three main groups.
A rock that forms when hot, liquid rock material cools and hardens into a solid is called an igneous rock.  Some igneous rocks form from magma, below Earth's surface. Magma may also reach all the way to Earth's surface before cooling and hardening.
 
A rock that forms from pieces of other rocks that are squeezed or cemented together is called a sedimentary rock. Weathering breaks down rocks into bits and pieces of sediment. The sediment is carried away by the forces of erosion. Eventually the sediment is deposited.  The pressure, or weight increases. The upper layers press down the sediment in a bottom layer. This can cause very fine particles to become squeezed together and harden into a layer of solid rock.
A rock that forms from another kind of rock that is changed by heat, pressure, or by chemical reaction is called a metamorphic rock. Metamorphic rocks often form deep underground where temperatures are high, and the pressure is great from rocks above. Metamorphic rocks also form when rocks come in contact with hot magma or lava.
Rocks are continually changing from one kind into another in a never ending process called the rock cycle. The rock cycle has no beginning and no end.
And this is the rock cycle.
    

Lift,Carry and Drop

In this topic I learn about how wind, water, and ice reshape the world.
 
The downhill movement of Earth material caused by gravity is called mass wasting. How steep a slope is will affect mass wasting. It can happen slowly, particle by particle, over years, or it can happen suddenly after a heavy rain or an earthquake.
The sediment is dropped off at the bottom of the hill or at places where the hill becomes less steep. The dropping off of sediment is called deposition.
Erosion and deposition work together.
Wind can blow sediment.
Flowing water carries loose particles of rock. The pieces of rock carried by moving water act like tiny drills. The pieces of rock erode the sides and bottom of the river. When the water slows down, some of the particles are dropped off.
A huge sheet of ice and snow that moves slowly over the land is called a glacier. Some glaciers form in valleys high up in the mountains. Others form near the poles. Glaciers form when more snow falls in the winter than melts in the summer.
 The whole sheet of ice moves downhill. When a glacier moves over the ground, pieces of rock may freeze into the ice. Huge chunks of rock may be picked up and carried long distances.
Glaciers eventually reach places where it is warm, and they melt. When the ice melts, the rocks that were frozen into it fall to the ground. A jumble of many sizes of sediment deposited by a glacier is called a till.
A deposit of many sizes of sediment in front of or along the sides of a glacier is called a moraine. As the glacier melts away, the moraine is left as mounds or long ridges. Glaciers also form lakes.
And this is how is carry,lift and drop.
    

Building Up and Breaking Down

When the crust moves, the rocks of the crust can change. They can change position. These changes may cause mountains to be made. The most common type of mountain is made mostly of rock layers folded by being squeezed together. This is called a fold mountain. A fault is a large crack in rocks along which there is movement. A mountain made by huge tilted blocks of rocks separated from surrounding rocks by faults is called a fault-block mountain. At the same time that forces are building up the crust, other forces are breaking down the crust. The two main forces breaking down the crust are weathering and erosion. The breaking down of rocks into smaller pieces by natural processes is called weathering. The picking up and removal of rock fragments and other particles is called erosion.  The end result of weathering is soil. Soil is a mixture of weathered rock, decayed plant and animal matter, living things, air, and water.  Plants and animals live in and on the soil. When they die, their remains enrich the soil. Rocks in the soil break down into smaller and smaller pieces.  Slowly the soil develops distinct layers. Any of the layers of soil from the surface to the bedrock below are called soil horizons. Below the soil is weathered rock and rock layers. Water that soaks into soil and rock by collecting in the spaces between the rock particles is called groundwater.  Poor soil can be improved by adding fertilizers. It can also be improved by adding humus. Humus is material in soil produced by the breakdown of plant and animal material. Humus helps soil absorb and retain water. And is what I learn.