Final Review Flashcards
Photosynthesis Equation
CO2 + H2O + sunlight=C6H12O6 + O2
carbon dioxide + water + light energy=glucose + oxygen
(!) Simplified Photosynthesis Definition:
The conversion of carbon dioxide into organic compounds using water and light energy.
Explain the process of photosynthesis
Carbon dioxide and light energy and water used to produce byproducts oxygen and glucose.
Discuss Transpiration and mechanisms that allow it
1. Water absorbed by roots and root hairs 2. Water molecules exposed to air and evaporate through pores (i.e., stomata) in leaf (process is transpiration) 3. Water molecules “pull” each other up against gravity due to cohesion and adhesion (and water potential)
Capillary action (adhesion and cohesion)
Adhesion: Attraction of molecules of one kind to another kind (adhesion)
Transpiration definition
Process of water evaporating through leaves is transpiration
*Adhesion is when molecules are attracted to _______ while cohesion is where molecules are attracted to __________.
- other kinds of molecules
- each other
Visible vs reflected light
Pigments allow plants to absorb energy. Wavelengths that are not absorbed are reflected. Plants don’t absorb green so they are reflecting it.
!We see color because visible light represents wavelengths that are _________.
reflected.
(!)Transpiration is the …
evaporation of water through plant leaves.
What colors/wavelengths are reflected vs absorbed.
Green is reflected.
Red and Blue absorbed.
Endosymbiotic Theory
Eukaryotes evolved when different types of free-living prokaryotes were incorporated inside larger eukaryotes (engulfed but not digested).
Endosymbiosis
symbiosis in which one of the symbiotic organisms lives inside the other.
(Early eukaryotes gained chloroplasts and mitochondria through endosymbiosis.)
Evolution by natural selection requires that:
- individuals in a population VARY in some trait.
- at least some variation is genetically-based (=heritable).
- certain genotypes produce more surviving offspring than others.
- differences in survival among genotypes are due to are due to an an agent of selection.
Species:
a group of individuals capable of interbreeding, and reproductively isolated from other groups.
Speciation:
Isolation followed by genetic divergence.
1) One population becomes separated into two populations (often by a physical barrier but not always)
2) Each population independently experiences natural selection
(may also experience mutation and genetic drift)
3) When/if the populations overlap again, they no longer interbreed
Allopatric speciation:
a physical barrier arises that prevents interbreeding.
Sympatric speciation:
no physical barrier arises; interbreeding between groups stops for another reason.
Three critical processes:
- Isolation/ separation
- Genetic divergence
- Reproductive isolation
Speciation is complete when…
Speciation is complete if the two populations/species can no longer interbreed when they encounter each other. Meaning, there is no longer any gene flow.
Node
common ancestor at time of split; each node represents a speciation event.
Branches:
a lineage (e.g., species through time)
Phenotype
observable traits expressed by an organism
genotype
underlying genetic makeup of an organism, either entirely or for a specific trait, both physically visible and non-visible (e.g., non-expressed alleles)
Evolution
a change in allele frequency over time in a population of organisms
Genetic drift
random changes in allele frequency from generation to the next
-bottleneck example with jar of red and yellow beans
Gene Flow
transfer of alleles from one population to another (usually involves movement of individuals)
-ie: snow geese; brown and white in population 1, brown only in population 2 but white migrate from population 1 to population 2.
Monophyletic group
“natural group”
clade
the most recent common ancestor and ALL its descendants
Paraphyletic group
part of Non-monophyletic group
the most recent common ancestor and SOME of its descendants
Non-monophyletic group
“artificial group”
grade
some members are more closely related to organisms outside the group
polyphyletic
part of Non-monophyletic group
similar characteristics, no shared ancestor
Eukaryotic vs. Prokaryotic Cells
- Eukaryotic cells have true nuclei and membrane-bounded organelles.
- Organelles: “Little organs” of a cell. Organelles can be membrane bounded or not (e.g., ribosomes do not have a membrane).
- Prokaryotic cells are structurally more simple than eukaryotic cells (no nuclear membrane).
Eukaryotes (difference from Prokaryote)
- have a nuclear envelope
- often (except for plants) no cell wall (allows for movement)
- sophisticated cytoskeleton
- vesicles for digestion
- Organelles
diploid-dominant
multicellular diploid stage is the most obvious life stage
-diploid meaning both sets of chromosomes
-only haploid cells, meaning one set of chromosomes, are the gametes
-gametes are the reproductive sex cell
-humans and most animals are diploid dominant
human chromosomes (46); 23 from each parent
alternation of generations
haploid and diploid stages both multicellular and both dominate at some point
• Multicellular structures develop to protect the reproductive structures
- Aided the transition to life on land
- Plants and some algae have an “alternation of generations”
gamete
mature reproductive or sex cell that contains a haploid number of chromosomes
Mitosis Vs Meosis
Mitosis goal is growth (two identical cells);
Goal of meiosis is diversity (make 4 different cells that are all haploid)
what’s the product of meiosis?
haploid
what’s the product of fertilization
diploid
zygote
(single cell, 2n): produced by syngamy (aka fertilization) from gametes
gamete
(single cell, n): produced by mitosis goes through syngamy to produce the zygote
Fungi
eukaryotic organisms that are more closely related to animals than to plants
List 3 characteristics of Fungi
1) ABSORB nutrition
2) CHITIN in cell wall
3) HETEROTROPHIC
What two sequences does fungi syngamy require?
1) plasmogamy: fusion of the cytoplasm
2) karyogamy: fusion of the nuclei
plasmogamy:
fusion of the cytoplasm
karyogamy:
fusion of the nuclei
