1. Chapter 1
Exploring Life

2. Why is now “Biology’s Most Exciting Era?”
They all have one ting in common

3. We recognize life by what living things do
Such as:
Evolutionary adaptation
Responding to the environment
Growth & development
Reproduction
Regulation
Energy processing

4. Some properties of life
Figure 1.2
(c) Response to the environment
(a) Order
(d) Regulation
(g) Reproduction
(f) Growth and development
(b) Evolutionary adaptation
(e) Energy processing

5. The studied hierarchy of life
Concept 1.1: Biologists explore life from the microscopic to the global scale
The studied hierarchy of life
Extends through many levels of biological organization

6. From the biosphere to organisms
Figure 1.3
1 The biosphere

7. Energy flows through an ecosystem
Usually entering as sunlight and exiting as heat
Producers
(plants and other
photosynthetic
organisms)
Consumers
(including animals)
Sunlight
Chemical energy
Heat
Ecosystem
Figure 1.4

8. From the biosphere to organisms
Figure 1.3
1 The biosphere

9. 6 Organs and organ systems
From cells to molecules
Cell
8 Cells
6 Organs and organ systems
7 Tissues
10 Molecules
9 Organelles
50 µm
10 µm
1 µm
Atoms
Figure 1.3

10. A Closer Look at Cells The cell
Is the lowest level of organization that can perform all activities required for life
25 µm
Figure 1.5

11. Two Main Forms of Cells
All cells share certain characteristics
There are two main forms of cells
In pairs create a list or Venn diagram of similarities and differences between the two main categories of cells. Your goal is to have the most CORRECT facts. You have 3 minutes.

12. Nucleus (contains DNA)
Prokaryotic cells
Lack the kinds of membrane-enclosed organelles found in eukaryotic cells
EUKARYOTIC CELL
Membrane
Cytoplasm
Organelles
Nucleus (contains DNA)
1 µm
PROKARYOTIC CELL
DNA
(no nucleus)
Figure 1.8

13. Map of proteins and their “network of interactions” in a fruit fly cell
Nucleus
Cytoplasm
Outer membrane and cell surface
Figure 1.10

14. Feedback Regulation in Biological Systems
Feedback regulation- a method of controlling a process by responding to the products that are created by said process
2 types:
Negative
Positive

15. Homeostatic Control—Negative feedback
1. Some variable changes to an abnormal level (stimulus)
2. The change is detected by a sensor
3. An effector message is sent to correct the stimulus
4. The effector adjusts the variable to desired level
Result decrease the initial stimulus/ return the variable to within the normal limits

17. Positive Feedback Positive feedback mechanism
Result  increase/amplify the initial stimulus

18. Standard Deviation… Take 2
Take 3 minutes to talk to the people around you about your pets (once you are in a group, stay in that group to avoid your information being counted twice). Make a data table in which you can record you data and calculate the standard deviation in a neat, organized fashion. (this will be collected and graded)
Calculate the standard deviation using the table model that is described on the “Standard Error Calculation” sheet.
What does the standard deviation tell you about your data? DO NOT WRITE THIS OUT discuss as a group

19. Standard Deviation… Take 2
After finding the standard deviation calculate the standard error.
What does the standard error tell you about your data? DO NOT WRITE THIS OUT discuss as a group
Now we will compile a class list of data for the number of pets each person owns. Once you have copied all of the data down into a new or new section of your existing group data table calculate the standard deviation independently.
Now calculate the standard error.

20. Standard Deviation… Take 2
ANSWER THESE on the paper that you will be turning in at the end of class:
If you have a small number for the standard deviation what does that mean about the data you collected?
If you think about the formula that is used to calculate the standard error (st error= st dev/# of data points), what should happen to the standard error as the number of data points increases? What does this change in the standard error tell you?