Science stuff

1. Ecology
Big Ideas

2. Energy
• Energy flows through every ecological system
– Inputs = what goes into the ecosystem
– Outputs = what goes out of the system

3. Food Webs
• Increased
biodiversity
means a
healthier
ecosystem

4. Energy Transfer between
Trophic Levels
• 10% Energy Transfer
• Producers make up largest biomass

5. Bioaccumulations
• Toxins cannot be
removed and
increase in amount
between trophic
levels

6. Carbon Cycle
• Cyclescarbon through the ecosystem
• Contains photosynthesis and cellular respiration
– Opposite chemical reactions

7. Nitrogen Cycle
• Cycles nitrogen
through the system
• Bacteria takes
nitrogen from the
atmosphere and
transfers it to
plants

8. Population Growth
• Populations will grow exponentially if there
are no limitingfactors

9. Population Growth
• Populations will reach carryingcapacity
because of limiting factors which include:
– Abiotic (non-living)
• Space & Water
– Biotic (living)
• Food & Predators

10. Population Density
• Population Densityis the number of living
things in an area
– Example:
• 500 moose in 10 sq. miles = 50 moose per mile

11. General Ecology
• Non-native species usually DIE in a new
environment, some survive and take over if
they have no predators

12. Sustainability
• Maintaining resources for future use
• Choices we can make now that support
sustainability
– Substituting renewable (?) for non-renewable (?)
resources
– Recycling
– Using fewer resources

13. Macromolecules
• Carbohydrates: made of simple sugar units
glucose, galactose, fructose
• Lipids: fats, etc.
– Triglycerides made of glycerol
& 3 fatty acid tails
– Phospholipids made of
phosphate head & 2 fatty
acid tails

14. Macromolecules
• Proteins: made of amino acids
• Nucleic Acids – DNA & RNA: made of
nucleotides

15. Cell Structure & Function
Big Ideas

16. Main Cell Types
• Prokaryotes – no nucleus, nucleoid region of
DNA; bacteria
• Eukaryotes – DNA contained in nucleus,
membrane bound organelles; everything
except bacteria

17. Key Cell Components/Organelles
• Nucleus – DNA
• Ribosomes – Site of Protein Synthesis
• Endoplasmic Reticulum – assembly of lipids & finishing
work on proteins, etc.
• Golgi Apparatus – modifies, sorts and packages
proteins, etc. from ER for storage or release to outside
of cell.
• Mitochondria – breakdown of glucose into ATP
• Chloroplasts – convert sun energy into sugars
• Vacuoles & Vesicles – storage/movement of water, etc.
• Lysosomes – bread down of macromolecules and old
organelles.

18. Cell Boundaries & Movement of
Materials Across Them
• Cell wall – rigid structure outside cell
membrane for support, protection; found in
bacteria, fungi, plants
• Cell membrane – flexible barrier between
inside and outside of the cell
– Composed of phospholipidbilayer, proteins
– Selectively permeable – allows some things
in/out, but not others.

19. Cell Transport
• Passive Transport – no cellular energy used
– Diffusion – movement of materials from high to low
concentration
– Facilitated diffusion – diffusion of molecules through
protein channels (not directly through membrane)
– Osmosis – movement of water from high to low
concentration across a membrane (facilitated)
• Active Transport - requires cellular energy
– Movement of materials across the membrane from
low to high concentration

20. Photosynthesis and Cellular
Respiration
Big Ideas

21. Photosynthesis & Cellular Respiration
• Photosynthesis and cellular respiration are
opposite chemical reactions

22. • Photosynthesis: plants take carbondioxide
(CO2) and water (H2O) and make glucose
(C6H12O6) and oxygen (O2)
– Plants make their own food!!!!!!!!!!!!!!!!

23. • Cellular Respiration: plants AND animals make
energy (ATP) by transforming glucose
(C6H12O6)and oxygen (O2) into carbondioxide
(CO2) and water (H2O)
– CHEMICAL Energy in glucose is transformed into
the energy to live (ATP)
– Very similar to setting something on fire
(combustion), which releases carbon dioxide (CO2)
into the atmosphere

24. Be able to trace the path of a carbon atom
from air through photosynthesis,
cellular respiration and back to the air

25. Mitosis and Meiosis
Big Ideas

26. Mitosis & Meiosis
• Division of Chromosomes in a cell
• Chromosomes are made of DNA
• DNA is replicated (copied) before each process
• Each chromosome contains many sections of
DNA called genes which contain the code for a
protein

27. Mitosis
• Mitosis: produces twoIDENTICAL cells from
one cell for growth and repair of body cells
• 2N cells produce 2N cells

28. Meiosis
• Meiosis: produces four UNIQUE sex cells for
reproduction
• Each cell is 1N – ½ the chromosomes of the body
cells
– Females: Eggs
– Males: Sperm
• Allows for differences (variation) in populations
• Fertilization restores the 2N number in offspring

29. Mitosis and Meiosis

30. DNA and Genetics
Big Ideas

31. DNA: deoxyribonucleic acid; is a code for your
physical (phenotype) traits
- PHYSICAL
TRAIT
DNA & Genetics

32. Traits
• Proteins: can be used to make
bodystructures, hormones and enzymes
– Enzymes act to speedup (catalyze) chemical
reactions in the body
• Ex. Digestion of food, making DNA, and regulating
glucose

33. GeneticsVocabulary
• Phenotype: What your physically look like
• Ex. Blue Eyes OR Brown Eyes
• Genotype: What your genesare
• Ex. Bb, bb, or BB

34. Vocabulary
• Dominant:Trait/gene that is shown
• Ex. BB = Brown EyesBb = Brown Eyes
• Recessive: Trait/gene that is hidden by a
dominant gene
• Ex. bb = Blue Eyes Bb = Brown Eyes

35. Vocabulary
• Heterozygous: different genes
– Ex. Bb for Brown Eyes
• Homozygous: same genes
– Ex. bb for Blue Eyes

36. • PunnettSquare: used to predict offspring
– Ex. Two heterozygous bunnies are crossed; black fur is
the dominant trait
– Phenotype ratio
• Ex. 25% white bunnies, 75% black bunnies
– Genotype ratio
• Ex. 25% bb, 50% Bb, 25% BB
F
F
f
f
FF Ff
Ff ff

37. Earlobes (E)
A detached earlobe man (EE) has children with an
attached earlobe woman (ee).
1) What are the possible genotypes (gene
combination)?
2) What are the possible phenotypes (physical trait)?

38. • A heterozygous tongue roller (Tt) mates with a
non-tongue roller (tt), what percentage of
their children will be tongue rollers?

39. • What is the percent chance two heterozygous
tongue roller will have a non-tongue roller
offspring?

40. Dihybrid crosses – chance of inheriting 2 traits together
Cross 2 heterozygous for color and height
(Green & Tall are dom; Yellow & Short are rec.)
TTGG TtGG TTGg TtGg
TtGG ttGG TtGg ttGg
TTGg TtGg TTgg Ttgg
TtGg ttGg Ttgg ttgg
TG tGTgtg
TG
tG
Tg
tg
Red = tall
Black= short

41. Protein Synthesis
• Transcription
– The code in DNA is copied into mRNA
– This nucleotide sequence determines the sequence of amino
acids in the protein.
– mRNA leaves the nucleus and forms a “protein factory”
complex with rRNA called a ribosome.
• Translation
– The nucleotide sequence in mRNA is read 3 nucleotides at a
time – a codon.
– Each codon corresponds to a specific amino acid.
– tRNA brings the needed amino acid to the ribosome.
– The amino acids are bonded together to form a protein.

42. Transcription Translation

43. Evolution
Big Ideas

44. Evolution
• Evolution: change over time
All living things are related
to a
COMMON ANCESTOR!!!

45. Evidence of Evolution
• Evidence:
1. Presence of Fossils found in rock layers
1. Homologous and Vestigial Structures
• Homologous: Similar Structures
• Vestigial: Unused structures; whale pelvis, human
wisdom teeth

46. Fossil Record Homologous Structures

47. Evidence of Evolution
3. DNA Comparisons
• Humans and mice are 99% similar in DNA, so they are
closely related
4. Embryos
• Closely related organisms have similar embryos

48. DNA Comparisons Embryos

49. Natural Selection
• Natural Selection: “survival of the fittest,
failure of the worst”
– Over reproduction sets up a struggle for existence
– Natural selection selects for variations in the
population (result of mutation & sexual
reproduction( that are adaptive
– The “goal” of life is to
survive and reproduce
(pass adaptive genes to
next generation)

50. • Mutations in DNA: can (not always) lead to
unique traits, which may help or hinder
survival!!
Organism Environment Unique Trait
Bunny Rabbit Winter
Cactus Desert
Cheetah African Savanna
Chameleon Jungle
Peacock Mating Season

51. Mutations

52. Balancing Biological Systems
Homeostasis

53. • Homeostasis: regulation of systems to
maintain balance
• Two things can affect homeostasis
– Negative Feedback
– Positive Feedback

54. Negative Feedback
• Negative Feedback: increase causes decrease,
decrease causes increase
– Ex. AutomaticThermostat: if temperature
decreases in room, then the temperature
increases
–Negative ≠ bad

56. • Positive Feedback: increase causes increase;
decrease causes decrease
– Ex. No shower for 2 weeks: smell from bacteria
growth increases on a daily basis
• Positive ≠ good
Positive Feedback

58. Negative or Positive Feedback??
Deforestation
Regulating Body
Temperature (too
hot OR cold)
Immune System
Fighting Infection
Body is
Hungry
P
P
N
N

59. Choose two examples to complete a Negative
Feedback Loop AND a Positive Feedback Loop
• Identify what HOMEOSTASIS would be
• Explain the STIMULUS that tells us
homeostasis is not in balance
• Identify the CONTROLCENTER in the body (if
there is one) that recognizes the stimulus
• Explain what RESPONSE occurs

60. Other System Examples
• Boundaries, inputs and outputs in an ecosystem
(energy, biogeochemical cycles, population
dynamics, etc.)
• Interaction of enzymes, substrates and products
in biochemical pathway
• Organ systems

61. Scientific Method
• Reliability –
– Increased by repeating an investigation = more trials
• Validity –
– Increased by:
• Adding more controlled variables
• Improving measuring technique
• Controlling for sample bias
• Including an experimental control group

62. Different types of investigations
• Controlled experiments
– A lab investigation in which the values of all variables are kept the
same except for one that is changed from experiment to
experiment (manipulated variable) and one that is measured
(responding variable).
– Have experimental and control groups
– Include at least 3 levels of manipulated variable (if measuring
effect of fertilizer on plant growth, use 10 g., 20 g. and 30 g. of
fertilizer on different plants)
– Include at least 3 trials for each condition (can be repetitions or
more subjects).
• Field study
– A scientific study of free-living plants or animals in which the
subjects are observed in their natural habitat without changing,
harming, or altering the setting or subjects.
– No experimental and control groups
– May include sampling, observation, etc.