BIOLOGICAL ORGANIZATION
This is the smallest unit of life capable of carrying out all life processes.
What is a cell?
According to cell theory, all living organisms are composed of one or more of these.
What are cells?
This scientist observed thin slices of cork under a microscope in 1665 and coined the term 'cells.'
Who is Robert Hooke?
All living organisms are composed of one or more of these basic structural and functional units.
What are cells?
This level of biological organization is formed when two or more different tissues work together to perform a specific function.
What is an organ?
A group of similar cells working together to perform a specific function forms this level of biological organization.
What is a tissue?
This statement of cell theory explains that new cells can only be produced through the division of existing cells.
What is 'All cells come from preexisting cells'?
Known as the 'Father of Microbiology,' this scientist was among the first to observe living microorganisms, which he called 'animalcules.'
Who is Antonie van Leeuwenhoek?
This characteristic of life involves all the chemical reactions an organism uses to obtain and transform energy and materials.
What is metabolism?
A single-celled bacterium takes in nutrients, uses energy, and reproduces. This demonstrates ______.
What is life processes? (characteristics of life)
The heart contains muscle, nervous, connective, and epithelial tissues that work together. This makes the heart an example of what level of organization?
What is an organ?
A scientist discovers a new microscopic organism consisting of only one cell. Explain why this organism does not violate cell theory.
What is 'Cell theory states that all living things consist of one or more cells', so a unicellular organism follows cell theory'?
After studying plant tissues, this scientist concluded that all plants are composed of cells.
Who is Matthias Schleiden?
When a person's body temperature rises, they begin sweating to cool down and maintain a stable internal environment. This demonstrates which characteristic of life?
What is homeostasis?
A scientist observes a newly discovered microscopic organism that contains DNA, uses energy, and maintains homeostasis. However, it does not contain cells. Which major scientific theory would be challenged if this organism were confirmed to be alive?
What is cell theory? Specifically, the principle that all living things are composed of one or more cells.
Arrange the following levels of biological organization from simplest to most complex: organ system, cell, organism, tissue, organ.
What is cell → tissue → organ → organ system → organism?
A student claims that viruses are living organisms because they contain genetic material and can reproduce inside host cells. Which part of cell theory challenges this claim?
What is 'All living things are made of cells'? Viruses are not cellular and cannot reproduce independently.
Building on discoveries about plant cells, this scientist concluded that all animals are composed of cells, helping establish that cells are the basic unit of living things.
Who is Theodor Schwann?
A seedling grows taller in the presence of sunlight and bends toward the light. Identify TWO characteristics of life demonstrated by the seedling.
What are growth and development, and response to stimuli? The seedling increases in size while responding to light in its environment.
A researcher observes that damaged skin cells are replaced when existing cells divide. Which scientist's contribution to cell theory does this support, and which characteristic of life does the replacement process demonstrate?
Who is Rudolf Virchow, and what is growth and development? Virchow is associated with the principle that cells arise from preexisting cells, while cell division supports tissue growth and repair.
A scientist discovers that damage to the epithelial tissue of the small intestine prevents nutrients from being absorbed efficiently. List at least three levels of biological organization that will be affected.
What is damage to the tissue disrupting the function of the small intestine (organ), affecting the digestive system (organ system), and reducing nutrient availability for the entire organism?
A scientist claims to have discovered a living organism that formed spontaneously from nonliving material without any preexisting cells. If verified, which principle of cell theory would this discovery challenge, and why?
What is 'All cells arise from preexisting cells'? A verified living cell arising without a parent cell would challenge this principle of modern cell theory.
A scientist observes a cell dividing into two daughter cells. Which contributor to cell theory is most closely associated with the principle demonstrated by this observation, and what earlier belief did it challenge?
Who is Rudolf Virchow? He popularized the principle that all cells arise from preexisting cells, challenging the idea that cells could spontaneously appear from nonliving matter.
Over many generations, a population of bacteria becomes increasingly resistant to an antibiotic. Explain how genetic information and natural selection contribute to this change.
What is evolution? Heritable differences encoded in DNA can affect antibiotic resistance. Resistant bacteria are more likely to survive and reproduce, passing their genetic information to offspring. Over generations, resistance becomes more common in the population.
A student argues that a virus must be alive because it contains genetic material, evolves over generations, and can produce more viruses inside a host. Use cell theory and TWO characteristics of living things to evaluate the student's argument.
What is 'Viruses have genetic material and can evolve, but they are not made of cells, cannot carry out independent metabolism, and require host cells to reproduce'? Therefore, viruses are generally not classified as living organisms.