1. We all have these in common.
7 Characteristics of Life

2. Living things share 7 characteristics:
Living things are made up of units called cells.
Every organism is composed of at least one cell.
1.) single-celled or unicellular
2.) many-celled or multicellular

3. b. There are two broad categories of cells:
prokaryotic—no organized nucleus nor membrane bound organelles; found in bacteria and cyanobacteria
eukaryotic—do have an organized nucleus and membrane-bound organelles such as Golgi apparatus and mitochondria. All other organisms such as plants and animals have this kind of cell.

4. Living things reproduce.
There are two basic kinds of reproduction:
Asexual—only one parent and all offspring are identical; for example, binary fission of bacteria or amoebas.
Sexual—two cells from different parents unite to produce the first cell of a new organism.

5. 3. Living things grow and develop.
For single-celled organisms, growth is mostly an increase in size.
Multicellular organisms go through a process called development, where cells divide and differentiate into different kinds of cells.

7. 4. Living things obtain and use materials and energy.
All living organisms must be capable of releasing energy stored in food molecules through a chemical process known as cellular respiration..
Autotrophs (also called producers)—plants, most algae, and some bacteria obtain their energy directly from the sun through photosynthesis.

8. Cellular Respiration
Respiration All living organisms need energy. They get this by breaking down nutrients, such as glucose, inside their cells. This releases the energy from the nutrients. We can describe respiration as: the chemical reactions that break down nutrient molecules in living cells to release energy.

9. c) Heterotrophs (also called consumers)—most other organisms, rely on the energy stored during photosynthesis.
Herbivores—eat plants and other photosynthesizing organisms
Carnivores—eat the herbivores or other carnivores
Omnivores—eat both plants and animals
Decomposers—such as bacteria and fungi; obtain energy from the remains of organisms that have died

11. 5. Living things respond to their environment.
Organisms detect and respond to stimuli from their environment.
A stimulus is a signal to which an organism responds.
External stimuli include temperature and light.
Internal stimuli come from within, such as blood sugar level or feeling thirsty.
An adaptation refers to the process of becoming adjusted to an environment. Adaptations may include structural, physiological, or behavioral traits that improve an organism's likelihood of survival, and thus, reproduction.

12. 6. Maintain homeostasis
Homeostasis is the property of a system in which variables are regulated so that internal conditions remain stable and relatively constant. Examples of homeostasis include the regulation of temperature

13. 7. Living things are based on a universal genetic code (DNA).
The directions for inheritance are found in deoxyribonucleic acid or DNA.
The genetic code is basically the same for all organisms on Earth.

14. Levels of Organization
Organism
Organ System
Organ
Tissue
Cell

15. Cell Structure and Function Notes
Discovery of the Cell:
Mid 1600’s scientists began using microscopes to observe living things
Robert Hooke used microscope to observe thin slice of cork—dead plant material
Cork seemed to be made of box-like chambers—Hooke called cells
Anton van Leeuwenhoek discovered
living cells in pond water

16. Cell Theory: All living things composed of cells
Cells are the basic unit of structure and function in living things
New cells are produced from existing cells

17. Cell Parts and Their Functions:
Specialized cell parts called organelles— “little organs”

18. Cell membrane—determines what goes in and out of the cell

19. 2. Cytoplasm—gel-like medium that holds the organelles in position

20. 3. Nucleus—control center of the cell
Double membrane that surrounds the nucleus—nuclear membrane
Hereditary information inside the nucleus—chromatin (DNA)

21. 4. Ribosomes—makes proteins

22. 5. Rough Endoplasmic Reticulum (rough ER)— makes and transports proteins within the cell
Called rough ER because of the ribosomes found on its surface

23. Smooth Endoplasmic Reticulum (smooth ER)—makes and transport lipids and other materials within the cell
Called smooth ER because no ribosomes found on its surface

24. Cytoskeleton—network of protein
filaments that helps cell maintain its shape

25. Golgi apparatus—processes and
packages proteins and other substances produced in the ER

26. Mitochondria—energy source of the cell
(powerhouse)

27. Vacuoles—sac-like structures for storage
Plant cells usually contain a large vacuole that fills most of the cell—pressure from this large vacuole helps plants support themselves

28. Found in animal cells only:
Lysosomes—cleans up the cell and
digests unwanted materials

29. Found in plant cells only:
Cell wall—provides support and
protection for cell
Composed mainly of cellulose (plant starch)—fiber for our diet
Chloroplast—makes glucose using the energy
from the sun (photosynthesis)

30. Specialized Parts for movement:
1. Cilia (like little hairs) 2. Flagella (like a tail)

31. Specialized Cells:
Different cells in your body do different jobs. The structure (how it’s built) of cells matches the function (what it does).

32. Plant Examples:
Leaf cell—contains many chloroplasts to maximize photosynthesis
Root cell (potato)—contains many vacuoles to maximize water and starch storage

33. Which cell might contain many mitochondria to produce more energy for movement?