steps of the scientific method
1.ask a question
2. do background research
3. form hypothesis
4. test with experiment
5. analyze results
6. draw conclusion
7. communicate results
what is discover based science
describes nature, Requires inductive reasoning.
Goal is to gather information and often leads to a hypothesis little to no manipulated variables
hypothesis based science
Starts with observation but then asks a testable question.
Answers "how" and "why" questions.
Has independent and dependent variables
factor that is changed by the experimenter
changes as a result of
manipulating the independent variable , the
constant throughout the
No membrane bound organelles or nucleus.
Always single celled
Bacteria and archaea
Membrane bound nucleus and organelles.
More specialized and complex than prokaryotic
Plants and animals.
Independent or aggregate
Dependent on other cells
organisms that synthesize their own food
organisms that cannot synthesize their own food and rely on other organisms for nutrition
Cheap and easy to care for.
Quick generation times.
(3-5 days to become an adult for C.elegans)
1st eukaryotic organism to have its entire genome sequenced.
Share biological characteristics with humans
Gonad contains sperm
Oocyte in gonad
3 reasons cell division is important
stages of the cell cycle
I: Preparation for division, includes G1, S & G2.
G0: Resting cycle. Cell has left the replication cycle.
G1: Cells increase in size. Most of cell's proteins have been synthesized.
S: DNA Replication occurs.
G2: Continued cell Growth
M: mitosis, cell divi
which cell undergoes binary fission
which cells undergo mitosis
which cells undergo meiosis
eukaryotes also undergo
to make genetically identical daughter cells
growth, cell reproduction, tissue regeneration
diversity, continued evolution
1.) Prophase I 2.) Metaphase I
3.) Anaphase I 4.) Telophase I
5.) Prophase II 6.) Metaphase II
7.) Anaphase II 8.) Telophase II
mechanisms that cause genetic variation during meiosis
Exchange of genetic material between chromosomes ->unique chromosomes, new combinations of genes
Chromosomes from each parent assort randomly into daughter cell .
result of random line-up of chromosomes
Exchange of genetic
material between homologous
Results in recombinant chromosomes
Occurs in Prophase 1
Observed matches expected
Observed does not match expected
Law of segregation
Law of independent assortment
Law of dominance
Law of Segregation
Every organism has 2 alleles per trait
When gametes form (meiosis), alleles separate
Offspring only inherits one allele from each parent
Law of Independent Assortment
Each alleles in a pair separates independently
Allele inherited is a matter of chance
Result of independent movement of chromosomes in meiosis
Law of Dominance
Some alleles are dominant, some recessive
Organisms with at least one dominant will display the
phenotype of the dominant allele
While looking at one trait, you can determine the dominant and recessive allele.
Parents are heterozygous.
Gives a phenotypic ratio of 3:1 and genotypic of 1:2:1
Looks at two traits.
Phenotypic ratio of 9:3:3:1