Transcript Final review part 2:

Final review part 2:
Ecology and genetics
ecology
• A branch of biology that deals with
interactions between organisms and their
environment
Organization in the environment
• Biosphere: portion of the earth
where living things exist
• Biotic: grass, birds, squirrels,
trees
• Abiotic: temperature, light, soil
• Population: Group of species
• Community: living organisms
in a given area
• Ecosystem: community and all
its physical factors
• Habitat: place where an
organism lives
• Niche: role of an organism in
an ecosystem
SYMBIOSIS
A relationship where
2 species live closely
together.
SYMBIOSIS
MUTUALISM
relationship where both species
benefit
SYMBIOSIS
COMMENSALISM
relationship where one
organism benefits and the other
is neither benefited nor harmed
SYMBIOSIS
PARASITISM
One organism benefits while the
other is harmed.
Food chain and food webs
• Autotrophs: make food
• Heterotrophs: ingest food
• Producers: make food
(autotrophs)
–Ex. Green plants
Sun is the main source of
energy!
Know how to interpret food
webs!
Food web: interconnected
feeding relationship
Energy transfer in food webs
• Energy is transferred from the producers
to the primary consumers, to the
secondary consumers, ect.
Consumers
• Primary (first order): eat
producers
• Secondary: eat primary
consumers
• Tertiary/higher order
Consumers continued…
• Carnivores: eat meat (other
animals)
• Herbivores: eat plants
• Omnivores: consume both
• Scavengers: consume dead
and rotting animals
• Decomposers: break down
dead plants and animals,
return nutrients to soil
Ecological Succession
• Primary succession: changes
in an area that did not have
previous life forms- begins on
newly exposed surfaces
• Secondary succession: changes
in areas where the previous
community has been destroyedbegins on soil
• Pioneer communities: first
living organisms to colonize an
area
• Climax communities: stable
community
Biogeochemical cycles
• Nitrogen cycle:
bacteria convert nitrogen gas
into ammonia for plants
Process is known as nitrogen
fixation
Carbon/oxygen cycle:
photosynthesis and respiration
• What process puts oxygen into the
atmosphere?
• What processes put carbon dioxide into
the atmosphere?
• What processes put very large quantities
of carbon dioxide into the atmosphere?
WATER CYCLE
Water cycle
• Condensation
–Water vapor builds up in clouds
• Precipitation
–Rain, snow, etc
• Ground water
–Water basin underground
• Evaporation
–Water passes from a liquid to
a gas phase
• Transpiration
-water vapor exits plants via
leaves
What is a biome?
• Large geographic area that
has a particular climate, native
animals and plants, etc
climate
• The conditions such as
temperature and amount of
precipitation year-after-year
determine the climate of a
region.
Terrestrial Biomes
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Tropical Rain Forest
Grassland (prairies)
Tundra: very dry- permafrost, little precipitation!
Savanna
Desert: dry
Coniferous Forest (or Taiga)
Temperate deciduous forest- we live in one!
Aquatic Biomes
• Freshwater (lakes, ponds,
streams, etc)
• Marine (oceans)
Natural Resources
• Non-renewable:
–Fossil fuels (coal, oil, gas)
• perpetual:
–Sun, wind, hydropower,
geothermal
• renewable:
10% Law
• Only 10% of energy is passed from one
trophic level to the next
• If 2000 kilocalories of energy is found in
the primary consumers, how much energy
is present in the tertiary consumers
Genetics
Before scientists knew about
chromosomes and genes…
• Gregor Mendel
–pea plants
-traits are inherited through a
passing factor from parents to
offspring.
His Experiments…
• Crossed tall plants with short
plants- all offspring were tallthe offspring is known as F1
Law of Dominance
• some traits are dominant and
others are recessive
Law of segregation- cross out
• the two factors (alleles) for a
trait separate during gamete
formation
Law of independent assortment
• Traits are transmitted to
offspring independently of
each other
Incomplete Dominance
•
one trait is not dominantresulting in a blending phenotype.
• Ex. Mate a certain red and white
plants create a pink offspring
Codominance
• Both dominant genes are
expressed
• Ex.
–Spotted dog
–Blood type AB
Multiple alleles
• A trait that has more than two
different alleles (RRYY)
Sex determination
• Genotype of a female: XX
• Genotype of a male: XY
Sex-linked traits
• Gene for the trait is located on the
X chromosome
• Male only need one have one X
so nothing to cover the trait that is
why colorblindness is dominant in
males
Blood types
• A, B, AB, O
• O is the recessive
• A and B are codominant
• Cross a male with O and
female with blood type A--what blood type will their
children have?
What are the possible genotypes
for each blood type?
• Blood type AB
– AB
• Blood type O
– ii
• Blood type B
– Bi or BB
• Blood type A
– Ai or AA
What is a test cross? Why is one used?
• A test cross determines
genotype:
• Whether a particular
characteristic of a plant or
animal is homozygous
dominant or heterozygous
dominant
Vocabulary
• Genetics: study of how traits are
passed on
• Alleles: different copies of forms
of a gene controlling a certain
trait
• Autosome: not a sex
chromosome
Vocabulary (con’t)
• Homozygous: same alleles
– tt or TT
• Heterozygous: when alleles for
a certain gene are different
-Tt
Genotype vs. phenotype
• Genotype: genetic makeup of
an organism
• Phenotype: physical trait of an
organism
Monohybrid cross vs. dihybrid cross
• Dihybrid
–Two traits
–Ex. Ttpp X ttPp (how many
combinations of alleles do each
parent have??)
• Monohybrid- one trait
–Ex. Tt X tt
Be able to do punnett squares of all
types like we did in class.
• Genotypic ratio: ratio of the different
types of gene possibilities
–Ex. 1 TT: 2Tt: 1tt
• Phenotypic ratio: ratio of the different
appearances
–Ex. 3 tall: 1 short
More problems…
• Cross a homozygous green plant with a
yellow plant (green is dominant to yellow)
• Answer
– GG X gg
More problems…
• Incomplete dominance: cross a red flower
with a white flower
• Answer:
– RR x WW
– Offspring all have a genotype of RW and a
phenotype pink
Last problem…
• Incomplete dominance: cross two pink
flowers
• Answer:
– RW x RW (draw on board)
Random
KNOW: