exam 1 study guide Flashcards
What is the definition of biology?
Biology is the scientific study of life and living organisms
What are the major characteristics of life?
built of cells, grow and develop, reproduce, respond to stimuli, homeostasis, metabolism, evolution
what is the definition of a cell?
A cell is the basic structural and functional unit of all living organisms. It is the smallest unit that can carry out all the processes necessary for life.
what is metabolism?
the sum of all chemical reactions that occur within a living organism to maintain life.
what is catabolic reaction?
These reactions break down larger molecules into smaller ones, releasing energy in the process. For example, cellular respiration breaks down glucose into carbon dioxide and water, releasing energy.
What is anabolic reactions?
These reactions build larger molecules from smaller ones, requiring an input of energy. For example, photosynthesis builds glucose from carbon dioxide and water.
What did we predict would happen to carbon dioxide levels when dead and alive meal worms
were tested with CO2 sensors? What were the results of our experiment? In what units is
carbon dioxide measured? Be sure to be able to calculate results if I asked per meal worm, per
minute, per hours, etc
The prediction might be that alive mealworms will produce more carbon dioxide compared to dead ones due to their metabolic activity. The results should show higher CO2 levels from live mealworms. CO2 levels are measured in parts per million (ppm) or as a concentration in millimoles per liter (mmol/L
Are viruses alive?
Viruses are not considered alive by most biologists because they do not exhibit all characteristics of life, such as cellular organization or metabolism. They require a host cell to reproduce and cannot carry out metabolic processes independently.
what is science?
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe. It involves observing, experimenting, and analyzing phenomena.
What are the four steps of the scientific method?
Observation
Hypothesis Formation
Experimentation
Analysis and Conclusion
What is a hypothesis?
A testable prediction about the relationship between variables.
What is a control?
A standard for comparison in an experiment.
What is meant by accepting or rejecting a hypothesis?
Based on experimental results, a hypothesis may be supported (accepted) or refuted (rejected).
What is a theory?
A well-substantiated explanation of some aspect of the natural world, based on a body of evidence and repeatedly tested.
What is the difference in the use of the word theory in science compared to general use of the term?
Often used to mean a guess or hypothesis without substantial evidence.
What is pH?
pH is a measure of the hydrogen ion concentration in a solution, indicating its acidity or basicity
What is the range of pH?
The pH scale ranges from 0 to 14, where 7 is neutral, below 7 is acidic, and above 7 is basic.
What do acid solutions contain?
Contain higher concentrations of hydrogen ions (H+)
What do basic solutions contain?
Contain higher concentrations of hydroxide ions (OH-)
What general pH are most drinks?
Many beverages have a pH between 2 and 7. For example, soda is acidic (pH 2-4), while some mineral waters are neutral or slightly basic.
Why do plants tend to make alkaline (basic) compounds?
Plants may produce alkaline compounds to neutralize acidic soil conditions or to balance nutrient availability
What is a solution
A homogeneous mixture of solute and solvent (e.g., saline solution)
What is a solvent
The substance doing the dissolving (e.g., water).
What is a solute
The substance being dissolved (e.g., salt).
What is the cell theory?
- Lowest level of structure capable to perform all chemical reactions necessary to sustain life
- Arise from previously existing cells: mitosis
Who was one of the first scientists to observe cells?
Robert Hooke
What type of
cells did he observe?
cork cells
Why was the theory not proposed until the 1800’s?
The cell theory was formally proposed in the 19th century as microscopes improved and more evidence accumulated.
What is a light microscope?
Resolution limit:
~0.2μm (small bacterium)
Effective magnification limit:
~1000X size of specimen
Functional limitations: cannot resolve subcellular anatomical structures called organelles.
Can see: mitochondria, most bacteria, nucleus, most plant and animal cells
What are organelles: any of a number of organized or specialized structures within a living cell.
What is a transmission electron microscope (TEM)?
e- beam focused through thin section of specimen
Allows for study of internal ultrastructure of cells.
What is a scanning
electron microscope (SEM)?
e- beam is bounced off surface
Give topographical information about a specimen’s surface area
What type of images do SEM scopes yields?
producing three-dimensional images
What type of images do TEM scopes yield?
Produces high-resolution, two-dimensional images.
What type of images do light microscopes yield?
n practical terms, bacteria and mitochondria, which are about 500 nm (0.5 μm) wide, are generally the smallest objects whose shape can be clearly discerned in the light microscope; details smaller than this are obscured by effects resulting from the wave nature of light.
difference between magnification and resolving power
Magnification enlarges the image, while resolving power distinguishes between two close objects.
calculate amplification power of each of these
Ocular lens is 10x
3 objective lens
Red = 4x: 40x
Yellow = 10x: 100x
Blue = 40x: 400x
what stain is used for plants
Iodine is used for plant cells
what stain is used for animals
methylene blue or crystal violet is used for animal cells.
what are the functions of the cell membrane?
Regulates entry and exit of substances, provides protection, and facilitates communication.
what is the function of the nucleus?
Contains genetic material (DNA) and controls cellular activities.