Science : The basis of life Flashcards
Give examples of living forms of life forms
- Jellyfish
- Sprouts
- Tree (If alive)
- Cells
- Seed (Embryo of plants)
- Shelf fungi
- Egg (If alive)
- Coral
Give examples of non-living life forms
- Hair
- Tree (If dead)
- Viruses (Don’t do anything on their own)
- Prion proteins
- Robot
- Proteins (Organic, simple, molecules)
What are the five criteria used to determine whether or not something is alive
- Living things need energy
- Living things produce waste
- Living things respond and adapt to their environment
- Living things reproduce
- Living things grow
Why are the 5 criteria not universally agreed upon by scientists?
There are additional things like movement, breathing and other things that are included in other people criteria to determine whether or not something is alive
What two creatures are especially problematic to define as living or non-living? Why?
Viruses
- Can’t replicate
- Can make us sick
- Needs a host (To perform life functions)
- Doesn’t use energy on their own
Prion
- Simple molecules
- Needs a host (To perform life functions)
What does the word abiogenesis mean?
A - Not
Bio - Life
Genesis - Origin
What is the other term for abiogenesis
Spontaneous generation
- Early philosophers like Aristotle (384-322 BCE) observed situations where it seemed living things arose from nothing.
How did Redi’s meat and maggots disprove the idea of abiogenesis? What year was it?
There was no spontaneous generation, the meat that wasn’t covered had to of been exposed to flys in the environment to grow the maggots.
1626 - 1697
How did Pasteur’s Swan-necked flask disprove the video of abiogenesis? What year was it?
“Active principle” in the air that caused things to go bad must be living organisms
1822 - 1895
The idea that life arises only from life was first proposed by … in …?
Rudolf Virchow in 1858
What were Robert Hooke’s cell theory and conclusions? What was the year?
- 1635 - 1703
- Looked through early 30x microscopes
- Looked at a thin slice of bark from Oaktree
Published his drawings
- Looks at plant cell wall of dead plants
- Discovered cells
- Reminded him of rooms where monks live
What were Antony van Leeuwenhoek’s cell theory and conclusions? What was the year?
- 1673 - 1723
- Inspired by Robert Hooks drawings
- Studied blood, cells, pond water and teeth scrapings
- Spotted “animalcules” moving on teeth
- One of the first observations of single celled organisms
Wrote about his work
- His observations were thought to explain the basis of life
What were Jacob Schleiden cell theory and conclusions? What was the year?
- 1804 - 1881
- All plants are made of cells
- Young cells have nuclei
New cells develop from nuclei
What were Theodor Schwann’s cell theory and conclusions? What was the year?
- 1810 - 1822
- Animal cells look different from plant cells but also have small spots
Small spots = nuclei
- Animal tissue must have nuclei
What is a theory in science?
Carefully thought out explanation or observations in the natural world that has been constructed using the scientific method. Bring together many facts + hypothesis
What is a scientific method?
Systematic observations, measurement and experiment and the formation, testing and modification of hypothesis
What is a scientific method?
Systematic observations, measurement and experiment and the formation, testing, and modification of hypothesis
Three components of modern cell theory are:
a. All organisms are composed of one or more cells
b. The cell is the smallest functional unit of life
c. All cells are produced from other cells
What is the manipulated variable?
Changed by the scientist b/c it is what’s being tested
What is the responding variable?
Remains the same throughout the experiment
What is the controlled variable?
Changes as a result of the manipulated variable
The earliest microscopes were … microscopes
Single-lens
How do scientists grow cells in a laboratory?
- Cells must be supplied with nutrients
- Waste removed
- Have ideal conditions to maintain life
What is the name of the most famous cell line used for research?
HeLa cell line
- Immortal
- Keep reproducing indefinitely
Where did the HeLa cell line come from?
Come from a woman who had cervical cancer, Henrietta Lacks, who died from the cancer in 1951.
- Used for research
What is a gene? What is a gene sequence?
- Sections of long molecules called DNA that hold genetic information
- DNA is constructed of thousands of molecules subunits
- Each sub-units contain 1 of 4 kinds of bases
What are 3 reasons that doctors might want to sequence a person’s genome
- Diagnostic-treatment
- Genetic disorders
- Screen infants in uterus
- Check for mutations that may increase of cancer
How is gene sequencing used to fight cancer?
- Most cancers are caused by damage to genes
- Mutations a risk cancer
- Info about gene-sequence helps researchers learn about how the gene affects cell activity
What are 3 reasons that doctors might want to sequence a person’s genome
- Diagnostic-treatment
- Genetic disorders
- Screen infants in the uterus
- Check for mutations that may increase of cancer
What is a stem cell?
“Blank slate”
- Can be used to divide to produce
- All other types of specialized cells
Why is stem cell research important?
Potential to grow into nerve cells for spinal and injury patients
- Skin injury-burns
- Can divide to become a multitude of cell types
- Treatment of disease
What does the term eukryotic cells mean?
- More xomplex cells, that have a membrane-bound nucleaus and specialized organelles
What does the term eukryotic cells mean?
- More complex cells, that have a membrane-bound nucleus and specialized organelles
- Makeup plants, animals, fungi and protists
How are prokaryotic cells different from eurkyotic cells?
“Simple cells”
- Lacking a membrane-bound nucleus
Examples of a prokaryotic cell
Bacteria and Archea
What is the function of the cell wall in a cell?
- Rigid
- Provides support
- Middle contains pectin and old cell together
What is the function of the cytoplasm in a cell?
- Jelly-like substance that contains organelles
What is the function of the cytoplasm in a cell?
- The power plant of the cell
- Sugar and oxygen combine to release walls and carbon dioxide and energy by chemical bonds breaking
What is the function of the nucleus in a cell?
- The control center of the cell
- Contains DNA, and RNA; for cell division and protein synthesis
What is the function of the Vacuole in a cell?
- Storage space for sugar, minerals, proteins
What is the function of the rough endoplasmic reticulum in a cell?
- Series of canals that carry material throughout the cytoplasm
- Ribosomes attach secrete proteins
What is the function of the smooth endoplasmic reticulum in a cell?
- Series of canals that carry material throughout the cytoplasm
- synthesizes fat/lipids
What is the function of the ribosome in a cell?
- Synthesizes proteins
- Cell structure, growth and maintenance
- Found free or in ER
What is the function of the chloroplast in a cell?
- Responsible for photosynthesis
What is the function of the cell membrane in a cell?
- Double layer
- Selective permeable
- Controls what comes in and out of cells
What is the function of the golgi body in a cell?
- Stores and rearranges proteins
- Releases vesicles
- Allow hormones and enzymes to be released from cells
What is the function of the lysosome in a cell?
- Contains digestive enzymes
- Break down food particles and foreign inaders
What is the function of the centrioles in a cell?
- Small protein bodies
- Attach spindle fibers during mitosis
- Hold organelles in place
What is the function of the nucleolus in a cell?
Makes ribosomal subunits from proteins and ribosomal RNA.
What is the function of the nuclear membrane in a cell?
Acts as a barrier that separates the contents of the nucleus from the cytoplasm
Two structures that are present in plant cells but not in animal cells
- Cell walls
- Chloroplasts
How are the mitochondria and chloroplast different from other organelles
They produce energy and have their own DNA
