U1M1 p1 slides Flashcards
What is Life?
how long ago was the earth formed
4.6b years ago
Cooling of the universe resulted in …
conversion of energy into subatomic particles
conversion of energy into subatomic particles resulted from
cooling of the universe
cooling of the universe resulted in conversion of energy into subatomic particles. what happened next?
- subatomic particles combined to form atoms
- elements react, fuse, collide to form large masses
what are the subatomic particles which form an atom
- -
what was the first element?
hydrogen
a few elements make up about 96% of the weight of most living organisms. What are they?
- oxygen
- carbon
- hydrogen
- nitrogen
oxygen, carbon, hydrogen, and nitrogen make up about how much of the weight of most living organisms?
96%
How much human body weight is composed of oxygen? (including water)
65%
how much human body weight is composed of carbon?
18.5%
how much of human body weight is composed of hydrogen? (including water)
9.5%
how much of human body weight is composed of nitrogen?
3.3%
All forms of life share common properties. What are they? (In this class)
- Order
- Reproduction
- Growth and Development
- Energy processing
- Response to the environment
- Regulation
- Evolutionary adaptation
Is a virus alive?
It is currently up to debate in the science community. There are arguments for both sides.
Make a case for a virus not being alive.
What is cell theory?
the theory that cells are the structural and functional units of life.
Make a case for a virus being alive.
What are the levels of biological organization in order? (largest to smallest)
- the biosphere
- ecosystems
- communities
- populations
- organisms
- organs and organ systems
- tissues
- cells
- organelles
- molecules
Who conducted the experiment in 1859 with the broth and flasks.
Louis Pasteur
what does cell theory say about the levels of biological organization?
Life begins with cells. Below cells are organelles, an organelle cannot be alive, therefore the cell is the smallest unit of life.
What did Louis Pasteur;s experiement with broth and flasks prove?
Cell arise only from growth & division of pre-existing cells.
When did Louis Pasteur conduct his experiment with broth and flasks?
1859
Explain Louis Pasteur’s experiment with broth and flasks.
- broth was boiled in various flasks for one hour to sterilize it and allow to cool, drawing in fresh air.
- one open flask allowed air and any bacteria present in the air to enter. The broth was contaminated with bacteria.
- another flask had a cotton plug which filtered bacteria from the air entering the flask. this broth remained sterile.
- finally a flask with a long neck had the bacteria removed from the air entering the flask by settling at the bottom of the curve. Again the broth remained sterile.
Before the theory that cells came from other cells, what was the belief?
Cells appeared spontaneously. Life could form from chemical reactions in the air.
All organisms/life forms are composed of one or more ______.
cells
The ________ is the smallest unit that has properties of life
cell
What is the technical definition of a cell?
Self-replicating chemical systems that commmunicate with each other and the environment
What are the two key features of life on earth?
unity and diversity
what is the unity of life?
“Two key features of life on Earth - Unity & Diversity”
all life is based on DNA and the common genetic code.
What is the unit which makes of genetic information?
DNA
What does DNA stand for?
DeoxyriboNucleic Acid
what controls the activities of a cell?
the genes
How are genes grouped?
very long DNA molecules called chromosomes
What is a gene?
- the unit of inheritance that transmits information from parent to offspring
- grouped into very long DNA molecules called chromosomes
- control the activities of the cell
what is the unit of inheritance that transmits information from parents to offspring
genes
what is the shape of DNA
a double helix
What are the estimates of the actual number of species in the world?
10 to 100 million
The diversity of life arises from …
differences in DNA sequences
How many species have been identified?
~ 1.8 million
_________ accounts for life’s dual nature of kinship and diversity.
Evolution
__________ is the central organizing principle of biology.
Evolution
What is the unifying theory of biology?
Evolution
How was natural selection inferred?
By connecting two observations.
- Individuals in a populationn vary in their traits, many of which are passed on from parents to offspring.
- A population can produce far more offspring than the environment can support
What is the mechanism for evolution?
Natural selection
________ explains the unity and diversity of life.
Evolution
What was The Origin of Species about?
Evolution
What is natural selection?
What is a hypothesis?
A testable statement used to build more complex inferences and explanations
Who wrote The Origin of Species
Charles Darwin
What is a scientific theory?
- well substantiated explanation (supported by a large and usually growing body of evidence)
- incorporates facts, laws, and tested hypotheses
- end point of science developed from extensive observation and experimentation
