Themes of Biology

How many species of organisms inhabit the earth? Approximately 40 million species inhabit the earth.

How many species have been identified? Approximately 2 million have been identified and only several thousand have been studied in detail.

How much is left to be studied? A WHOLE LOT!

What does “diverse” mean? Different Variety

Would you say that the world is diverse? Yes!

Biodiversity When we refer to the diversity of living things on earth, we call this biodiversity.

The Biosphere All living things and where they are found make up the biosphere.

The science of life or the study of all living things. What is biology? The science of life or the study of all living things.

6 Unifying Themes Cell Structure and Function Stability and Homeostasis Reproduction and Inheritance Evolution Interdependence Matter, Energy, and Organization

Cell Structure and Function The cell is the basic unit of life. All organisms are made of and develop from cells.

If an organism has only 1 cell then it is unicellular.

If an organism has more than one cell than it is a multicellular organism.

Cell Structure and Function Cells undergo a process called differentiation, in which they become specialized for various roles given by the DNA. EASY TO REMEMBER: DIFFERENTIATION MEANS DIFFERENT…CELLS ARE DIFFERENT.

Different Cells Bone Cell Nerve Cell Blood Cell

Homeostasis and Stability

Homeostasis and Stability How would your body respond if you ran a fever of 105 degrees? Answer: Sweat

What would happen if you jumped into Lake Hartwell in January? You’d Shiver! Coney Island Polar Bear Club

Stability and Homeostasis Living things from unicellular to multicellular maintain a stable level of internal conditions called homeostasis. Examples: water content, temperature, and food intake

Homeostasis The harp seal takes in food to maintain a thick layer of fat. Blood flow is adjusted according to the temperature of the water to maintain a stable body temperature. Harp Seal

Reproduction and Inheritance

Reproduction and Inheritance All organisms produce new organisms like themselves by transmitting hereditary information to their offspring. This process is called reproduction.

Reproduction and Inheritance Where is this hereditary information stored? Answer: DNA (deoxyribonucleic acid)

Reproduction and Inheritance In some organisms DNA exists in a structure made of membrane. In other organisms it exists as a loop.

Reproduction A short segment of DNA that contains instructions for a single trait is called a gene. or Blue Eyes Dark Eyes

Reproduction Sexual reproduction occurs when hereditary information from two parts of an organism or two organisms of the same species is combined.

What types of organisms sexually reproduce?

The kissing gourami

Reproduction When asexual reproduction occurs, hereditary information from different organisms is not combined. The offspring is basically a duplicate of the parent.

Where does asexual reproduction occur?

Bacteria

Evolution

Populations of organisms “evolve” or change over time. Evolution Populations of organisms “evolve” or change over time.

Natural Selection is the driving force behind evolution. Organisms that have certain favorable traits are better able to successfully reproduce.

Which frog is most likely to reproduce successfully?

Evolution The survival of organisms with favorable traits causes a gradual change in populations of organisms over many generations.

Interdependence of Organisms

Interdependence of Organisms Organisms interact with one another and are dependent on one another for survival. The branch of biology that studies the interactions between organisms and their environments is ecology.

How are we dependent on other organisms?

How are we dependent?

How are we dependent?

How are we dependent?

How are we dependent? OR Who doesn’t enjoy a nice piece of mutton? A warm wool sweater. OR

How are we dependent?

A nice country ride OR…

Matter, Energy, and Organization

Matter, Energy, and Organization Living things are highly organized and need a constant supply of energy.

Almost all energy for life on earth comes from the sun.

How do organisms obtain their energy?

Matter, energy, and organization… Organisms that obtain energy by making their own food are autotrophs. euglena

Matter, energy, and organization… Autotrophs use a process called photosynthesis in which energy from the sun, water, and carbon dioxide are used to make substances such as starches and sugars.

Metabolism is the sum of all chemical processes that happen within the body.

Matter, energy, and organization… Heterotrophs are organisms that must take in food to meet their energy needs. They must eat autotrophs or other heterotrophs.

What are examples of heterotrophs?

Herbivores

Predators

1. Give an example of homeostasis.

2. What are two types of reproduction?

3. Give an example of a single celled organism.

4. Do only living things use energy?

5. Give 3 ways that you are dependent on other organisms for survival.