Lecture 1 - Cells Flashcards
To classify something as alive, scientists have come up with 8 characteristics, what are they?
ORGSHARE: order, reproduction, growth and development, sensitivity, homeostasis, adaptation, regulation, and energy processing
One of these is not like the others: ladybug, ebola virus, prickly pear cactus, and e.coli bacteria, and why?
ebola virus is different because it is not a living organism
Define the 8 characteristics of life!
Order: must be organized and made up of cells
Reproduction: must be able to pass hereditary information to the next generation
Growth and Development: grow and develop
Sensitivity: must respond to stimuli
Homeostasis: must be able to maintain constant internal conditions
Adaptation: must be able to enhance ability to survive and reproduce
Regulation: must be able to control internal functions
Energy processing: must be able to take energy from the sun or food to use for their metabolic activities
Do viruses satisfy the properties of life? why or why not?
NO!
Order: not made up of cells
Reproduction: they do reproduce but only inside other organisms
Growth and development: NO
Sensitivity: no metabolism to make energy to respond to stimuli
Homeostasis: NO
Adaptation: Yes they can change their DNA and RNA structure
Regulation: NO
Energy processing: NO
What are viruses made up of if not cells?
nucleic acid + protein coat/envelope
What are the levels of biological organization?
atom, molecule, organelle, cell, tissue, organ, organ system, organism, population, community, ecosystem, biome, biosphere
Describe atoms.
atoms are the smallest unit of matter: contains a nucleus surrounded by electrons. Example: hydrogen and oxygen
Describe molecules.
cluster of at least 2 atoms held together by chemical bonds. Example: H2O. 4 classes of macromolecules: nucleic acids, protein, carbohydrates, lipids
Describe the 4 classes of macromolecules.
1) Nucleic acids DNA/RNA: polymers of nucleotides ( nitrogenous base + sugar + phosphate )
2) Protein: polymers of amino acids
3) Carbohydrates: polymers of sugars
4) Lipids: includes triglycerides, phospholipids, and steroids
Are lipids polymers of anything?
No
Describe organelles.
membrane bound subcellular structure that performs a specific function within a cell. Example: mitochondria or golgi
Describe cells.
the smallest unit that displays all the characteristics of life. Some organisms are single cellular and some are multicellular. Cells are prokaryotic or eukaryotic. Example: stem cell and osteoblast
Describe tissues.
groups of similar cells carrying out a main function. 4 major tissue types: connective, epithelial, muscle, and nervous
What tissue is blood?
connective tissue
Describe organs.
collection of tissues that together perform a specific function. Example: stomach, intestine, heart
Describe organ system.
several organs that work together to perform a specific function. Example: digestive system
Describe organism.
an individual living thing. can be composed of many cells, tissues, organs, and organ systems working together or can be a single cell. Example: one elephant, one tree
Describe population.
all the individuals of a species living within a specific area. Example: all of the african bush elephants living in the savanna
Describe community.
all the living organisms of all the different species interacting in one area. Example: all the plants, animals, fungi, and microbes in the savanna
Describe ecosystem.
all the living and non living parts of a particular area. Eg: the savanna
What is biotic and abiotic
biotic: all the plants, animals, fungi, and microbes
abiotic: 4 abiotic conditions required for all living systems: water, gas, temperature, and nutrients/energy
Describe biomes.
major ecosystem types: characterized by specific climate/physical conditions and the organisms adapted to those conditions. Example: desert, tundra, broadleaf forest