Biological Themes and The Characteristics of Life Is it a living thing?

What IS biology? the study of living things What is cellular biology? What is a cell?

What is a cell? the structural and functional units of all living organisms. simplest, functional unit of a living thing some organisms (ie. bacteria) are unicellular AND other organisms (ie. humans) are multicellular it can take in nutrients, convert these nutrients into energy, carry out specialized functions, and reproduce as necessary AND stores its own set of instructions for carrying out each of these activities.

Five Kingdoms Plantae Protista (ie. algae, ameba, slime mold) Fungi Monera (ie. bacteria) Animalia (ie. insects, birds, humans, clams, sponges)

There are 7 characteristics that unify all of life no matter how big or small the organism is.

All living things are made of cells. Cell must have a membrane and genetic material (ie. DNA/RNA) Organisms can be unicellular or multicellular If multicellular, cells will differentiate and take on specific structure and functions to maintain the organism.

All living things are organized. Atoms are arranged into molecules…molecules are arranged into organelles…organelles make up a cell…cells are arranged into an organism – a complete living thing.

All living things obtain & use energy for metabolism. Heterotrophs cannot make their own food, autotrophs CAN make their own food. Almost all energy on Earth comes from the sun and autotrophs convert/change it to usable energy during photosynthesis. CO2 + H2O + chlorophyll --- C6H12O6 + H2O + O2 radient energy Metabolism is all the chemical processes that occur in an organism’s cells. It changes food to fuel/energy for cell activities (ie. moving, thinking, growing).

All living things reproduce. Reproduction is not essential to the survival of the individual, but IS to the species. Asexual reproduction involves one parent CELL contributing DNA (ie. binary fission, budding, mitosis). Sexual reproduction involves two parents contributing DNA (ie. sperm and egg)

All organisms grow and develop. Living things grow in two ways: cell enlargement and cell division. Both are required for multicellular organism growth. Development of an adult organism occurs in multicellular organisms by cell division and differentiation.

All organisms move. The ability to move enables organisms to interact and respond to their environments.

All organisms respond to stimuli. In unicellular organisms, the cell membrane is in control of what gets into and out of the cell. All organisms respond to stimuli to maintain stable internal conditions - homeostasis Temperature, water, salt, waste/toxins, and food are some of the factors that affect homeostasis.