map scales

OUTER LAYERS OF THE EARTH

MATERIALS:
clay of different colors
cardboard
construction paper
Permanent markers
Pencils

Objectives:
Identify the different layers of the Earth.
Develop fine motors skills using clay.

Review for Science quiz

Any living being consisting of a single cell.
Most are invisible without a microscope but a few, such as the giant amoeba, may be visible to the naked eye.

The main groups of unicellular organisms are bacteria, archaea, protozoa, unicellular algae, and unicellular fungi or yeasts.

Some become disease-causing agents (pathogens).

All living things have a circle of life. Birth, growth, reproduction, and death are natural parts of the natural world.


A prokaryote is an organism that is almost always single-celled.
The prokaryote’s DNA travels openly around the cell.
All bacteria are prokaryotes.

An eukaryote is an organism that can either be single-celled or multi-celled, can reproduce in one of several ways (e.g. meisos, mitosis) and has a cell nucleus within which its DNA is contained.

Tissues

RUMINANTS

RUMINANTS
Animals having a rumen - a large digestive vat in which fibrous plant material is partially broken down by microbial fermentation, prior to digestion in a "true" stomach (the abomasum). There are also two other stomachs - the reticulum and the omasum. Typical ruminants are cattle and sheep.

mammal which chews cud, such as a cow or deer; chewing cud.

For the most part, the digestive system of ruminants is very similar to that of other mammals, but the stomach is considerably different from the so-called "monogastric" condition.

The word "ruminant" comes from the Latin ruminare, to think; and as wildly laughable as the idea of a cow "thinking" may be, nevertheless, the contemplative and placid expression on a cow's face as she "chews her cud" does sort of give the impression that she's dealing with serious world problems.

You may have heard it said that cows have "four stomachs."

In an anatomic sense this is incorrect; there really is only one stomach, but it does have divisions.

The first three divisions of the ruminant stomach are sometimes considered to be diverticula of the esophagus; there is considerable debate on this point, however, and some authorities consider them derivatives of the stomach.

SYMBIOTIC RELATIONSHIPS
Symbiosis is a close ecological relationship between the individuals of two (or more) different species. Sometimes a symbiotic relationship benefits both species, sometimes one species benefits at the other's expense, and in other cases neither species benefits.

Ecologists use a different term for each type of symbiotic relationship:

Mutualism
-- both species benefit
Commensalism
-- one species benefits, the other is unaffected
Parasitism
-- one species benefits, the other is harmed
Competition
-- neither species benefits
Neutralism
-- both species are unaffected

Indus Valley Civilization

CELLS

The Cell Overview
Early Contributions
Robert Hooke - The first person to see cells, he was looking at cork and noted that he saw "a great many boxes. (1665)
Anton van Leeuwenhock - Observed living cells in pond water, which he called "animalcules" (1673)
Theodore Schwann - zoologist who observed that the tissues of animals had cells (1839)
Mattias Schleiden - botonist, observed that the tissues of plants contained cells ( 1845)
Rudolf Virchow - also reported that every living thing is made of up vital units, known as cells. He also predicted that cells come from other cells. (1850 )

The Cell Theory
1. Every living organism is made of one or more cellss.
2. The cell is the basic unit of structure and function. It is the smallest unit that can perform life functions.
3. All cells arise from pre-existing cells.

*Why is the Cell Theory called a Theory and not a Fact?
Cell Features

Ribosomes - make protein for use by the organism
Cytoplasm - jelly-like goo on the inside of the cell
DNA - genetic material
Cytoskeleton - the internal framework of the cell
Cell membrane - outer boundary of the cell, some stuff can cross the cell membrane.

Types of Cells
Prokaryotic Cells
Prokaryotes are very simple cells, probably first to inhabit the earth.
Prokaryotic cells do not contain a membrane bound nucleus.
Bacteria are prokaryotes.
DNA of bacteria is circular.
The word "prokaryote" means "before the nucleus"

Other features found in some bacteria:

Flagella - used for movement
Pilus - small hairlike structures used for attaching to other cells
Capsule - tough outer layer that protects bacteria, often associated with harmful bacteria
Eukaryotic Cells
Eukaryotic cells are more advanced cells.
These cells are found in plants, animals, and protists (small unicellular "animalcules").


The eukaryotic cell is composed of 4 main parts:
cell membrane - outer boundary of the cell
cytoplasm - jelly-like fluid interior of the cell
nucleus - the "control center" of the cell, contains the cell's DNA (chromosomes)
organelles - "little organs" that carry out cell functions

ORGANELLES WITH DNA
* The Mitochondria and Chloroplasts have their own DNA
* ENDOSYMBIOSIS THEORY - eukaryotic cells evolved from the engulfing of bacteria cells, thus creating additional cell parts

CELL MEMBRANE
* Function: to regulate what comes into the cell and what goes out
* Composed of a double layer of phospholipids and proteins