Chapter 1 - Life Chemical, Cellular, and Evolutionary foundations Flashcards
What is observation?
the act of viewing the world around us
What is experimentation?
a disciplined and controlled way pf asking and answering questions about the world in an unbiased manner
What do observations allow us to draw?
tentative explanations (hypotheses)
What is a hypothesis?
a prediction that can be tested by observation and experimentation
What can observations do for a hypothesis?
a single observation can lead us to reject the hypothesis or support the hypothesis but cannot prove it
How do you undertake a controlled experiment?
conditions and set up kept as similar as possible for each group
researcher can then introduce differences (a variable) to see if it has an effect
Why is Evolution important in Biology?
it provides the most general and powerful explanation of how life works
What are both the living and non living worlds both subject to?
The laws of chemistry and physics
What do living things share with non living things?
All the elements that make up the living things can be found in non living things
What does carbon do?
provides the backbone of life
What are the 3 most abundant chemicals in organisms?
Carbon, Hydrogen and Oxygen
What % of known matter do hydrogen and helium make up?
99%
What elements make up most of the Earth’s crust?
Oxygen and Silicon mostly, with significant aluminium, iron and calcium
What is the first law of thermodynamics?
energy can neither be created nor destroyed: it can only be transformed from one form to another
What is the second law of thermodynamics?
the degree or disorder (or the number of possible positions and motions of molecules) in the universe tends to increase
What does entropy mean?
the amount of disorder (or the number of positions and motions of molecules) in a system
What were 2 experiments that support the hypothesis that life does not spontaneously occur?
Francesco Redi - Fly’s producing maggots on meat (open, closed, gauze)
Louis Pasteur - microbes and swan-neck flask
What is a cell?
simplest entity that can exist as an independent life unit
all cells contain a stable blueprint of information in molecular form; they have a discreet boundary that separates the interior of the cell from it’s external environment; they have the ability to harness materials and energy from the environment
What do nucleic acids do?
store and transmit information needed for growth function and reproduction
What does DNA stand for?
Deoxyribonucleic acid
What is DNA?
a double stranded helix, contains genetic material, made up of 4 bases A,T,C,G information in DNA directs formation of proteins
How is a protein formed?
Copy of DNA information to more DNA (replication)
Synthesis of RNA from a DNA template (transcription)
RNA read and Amino acids determined (translation)
what is a gene? (Protein coding)
the DNA sequence that corresponds to a specific protein product
What is one of the advantages of DNA?
it can be easily replicated and passed from cell to cell
How does replication work?
each strand of double helix serves as a template for a new strand
It is precise as if not mutations may occur from errors in DNA (altering function)
What is the plasma membrane?
separates living material within the cell from the non living environment around it
function is to control the movement of materials into and out of the cell
What is the nucleus?
houses the cell’s DNA
What does the nuclear membrane do?
selectively controls what goes in and out
What is the cytoplasm?
liquid medium of cell, place where chemical reactions occur
If a cell has no nucleus what type of cell is it?
prokaryotic
If a cell has a nucleus what type of cell is it?
eukaryotic