Download Biology Review – Final exam Be able to explain with 2

Biology Review – Final exam
1. Be able to explain with 2-3 sentences each what the importance of each of
the following adaptations was for plants as they evolved and adapted to life
on land. You should be able to explain how an adaptation is an advantage
over a previous version.
a. Example - Flowers – these are an adaptation found in Angiosperms.
Flowers evolved as a way to attract specific pollinators such that eggs
can be fertilized by sperm of plants of the same species that might be
some distance away. This helps with genetic diversity and can be
more specific if a bee brings pollen to a flower rather than relying on
wind-borne pollen the way Gynmosperm do.
b. Waxy cuticle and stomata –
i. Helps plants retain water
ii. Water not directly absorbed into leaves (as it would algae
where they are surrounded by water)
iii. Adaptation to land where exposure to air causes dehydration
iv. Cells are mostly water!
v. Because plant is covered cuticle, there has to be a way to get
gases in and out
vi. Stomata open and close to allow carbon dioxide in and oxygen
out
vii. Stomata can be closed if there is danger too much water loss.
c. Vascular tissue and roots –
i. On land, plants are no longer surrounded by water and
therefore need to carry things from one point to another
ii. Water and minerals need to be absorbed and carried up to rest
of plant - xylem
iii. Products of photosynthesis need to be carried from leaves to
rest of plant
iv. Allows plants to stand upright and leaves to reach for the sun.
v. Roots are designed to absorb water and anchor plants
d. Diploid dominant life –
i. After moss (bryophytes) plants tended to move to a diploid
dominant life
ii. Haploid organisms only have one set of each chromosome –
which means any recessive gene is automatically expressed,
there is less genetic variation.
iii. Diploid organisms have two sets of chromosomes – you can
mask dangerous recessive genes and have more variation
iv. Sporophyte – is the dominant diploid stage.
e. Pollen –
i. Male gametes (i.e. sperm) are carried in pollen
ii. Protects the gamete from drying out – previously algae had
water borne sperm
iii. Provides more mechanism for distribution
iv. Angiosperm and gymnosperm have pollen
v. Highly evolved pollinators in angiosperm
f. Seeds –
i. Only gymnosperm and angiosperm have seeds
ii. Protects embryo from drying out or being digested
iii. Provides a food source for the developing embryo
iv. Seed coat encases it
v. Made from ovules around fertilized eggs
vi. Also can provide dormancy
g. Fruit –
i. Fruit develops from ovary after eggs are fertilized and seeds
form
ii. Provides transport for seeds (when eaten by animals) or burrs
carried in your socks.
iii. Can provide mechanisms for broad geographic distribution
h. Cones –
i. Found in Gymnosperms
ii. Male and female cones – reproductive structures
iii. Pollen land on female cones
iv. At base of each scale there is a haploid egg that is fertilized
v. Seed develops at the base of scale from the zygote
2. Be able to describe the evolutionary advantage of the following trends in
animal evolution – see the following as an example:
For example: Internal fertilization was necessary when animals moved to
life on land. In the water, external fertilization is effective but only if both
the male and female produce large quantities of both sperm and egg. With
internal fertilization the male still needs to produce many sperm but the
female only produces a few eggs. The female’s investment comes in either
producing a protective “egg” around the developing embryo(s) or in
nurturing the embryo internally.
a. Symmetry
i. Duplication of body parts –
1. Asymmetry – like a sponge – unorganized – tend to be
sessile
2. Radial symmetry – like a wheel, has multiple planes of
symmetry – allows simple organization and movement
– jelly fish
3. bilateral symmetry – one side mirrors the others –
allows directional organization –front and back, left
and right – so led to cephalization
ii. Symmetry led to the ability to be more organized which
allowed more advanced features.
b. Body plan
i. Blue print of an organisms – related to symmetry
ii. No body plan (sponge) means no structure
iii. Sac body plan means one opening for both waste and food
iv. Tube within a tube – much more efficient – as animals more
complex need to use food resources better
c. Cell, tissue, organ, organ system level of organization
i. Different levels of organization are related to “advancement”
of animals – complexity
ii. Cell level – sponges, cells are barely specialized – little
codependence
iii. Tissue level – cells work together in a tissue for a common
function – cnidaria
iv. Organ level – tissues working together for common function –
platyhelminthes
v. Organ systems – organs coordination actions to carry out a
life function
d. Cephalization –
i. Concentration of nerves and sense organs in the head
ii. This is good because we can process sensory input in one
area that leads us and process that for the rest of the body
iii. Allows an organized response to environmental stimuli
e. Internal skeletons
i. Frame – we need to be supported in air – but also allowed
better structure in water
ii. Attachment for muscles – allows movement
iii. Protection of vital organs
f. External skeletons
i. Provides protection
ii. Provides an attachment for muscles
iii. Jointed appendages – movements
iv. Support in the air
g. Segmentation
i. Subdivision of body
ii. Repeated parts along length
iii. Allowed greater flexibility and mobility
iv. Organization by segment
v. Allows more complexity
h. Care of young
i. Increasingly through evolution, more energy put into caring
for young than in producing gametes
ii. One trend on land – also meant having a protected amniotic
egg and then caring for immature young
iii. Mammals – nurse their young
1. Marsupials (nurture embryo in pouch)
2. Monotremes (lay egg, but nurse young)
3. Placental (embryo develops internally)
3. In terms of existing conditions, relative complexity, and logical sequencing
of events, be able to explain why the following order of events makes sense
scientifically.
a. 4.5 bya Earth and our solar system are formed (example – Earth
formed from a condensation of swirling matter in a giant cloud of
matter spinning around a central sun. The initial conditions on Earth
were hot with molten lava, an atmosphere of primarily carbon
dioxide, methane, ammonia, water vapor not hospitable to life, little
protection from UV radiation due to a lack of significant atmosphere,
etc. But the Earth is in a position at a sufficient distance from the sun
that we can be warmed by the sun but not overheated. The minerals
in the material forming the earth would be the foundation of
molecules that evolved to form living cells.
b. 4 bya – simple organic molecules formed, polymerized, created
droplets
i. Living cells are made of organic molecules (proteins,
carbohydrates, lipids, nucleic acids)
ii. Organic molecules formed from raw materials of carbon
dioxide, water vapor, ammonia…..using energy of UV
radiation and lightning
iii. Simple organic building blocks need to be joined (hot rocks
and clay that allowed dehydration) to form polymers
iv. Eventually polymers of proteins and lipids could combine to
form cell like bubbles
v. RNA and proteins combine and RNA becomes self-replicating
c. 3.5 bya – first heterotrophic prokaryotic single cells arose (these
were Archaea – what kind of environments do they like?)
i. First cells were heterotrophic – (photosynthesis is too
complex) – liked extreme environments
1. Thermophiles
2. Acidophiles
3. Halophiles
ii. There were extreme environments so early life (if it was to
exist) had to endure those conditions
iii. Still no oxygen (so they were also anaerobic)
iv. Prokaryotes are simplest kind of cell so they were first
d. 2.7 bya – by now photosynthesis had evolved in prokaryotic cells, so
oxygen began to build up in atmostphere
i. Eventually photosynthesis evolved as an alternate method of
trapping energy in prokaryotes
ii. A by-product of photosynthesis is oxygen
iii. Oxygen in atmosphere allowed respiration to evolve
iv. Aerobic respiration allowed more efficient processing of
organic molecules
e. 2.1 bya – first eukaryotic single cells appear probably due to
endosymbiosis
i. Eukaryotic cells are more organized – compartmentalization
of functions (organelles)
ii. Probably the infolding of membranes in prokaryotes started
some of the process
iii. Endosymbiosis – was the ingestion and mutual relationship of
one prokaryote by another – for example ingesting a highly
aerobic prokaryote might lead to mitochondria, chloroplasts
probably evolved from photosynthetic prokaryote.
f. 1.5 bya – multicellular eukaryotic organisms evolved out of colonies
of eukaryotes.
i. Building colonies of cells started to allow division of labor
ii. Eventually these colonies became multicellular organisms
iii. Colonial choanocytes led to animals
iv. Colonial algae led to plants
4. Explain how the following pieces of evidence found in both mitochondria
and chloroplasts support the endosymbiotic theory:
a. Double membrane in both chloroplasts and mitochondria
i. Duh, if something was engulfed by another cell it would have
a double membrane – the inner membrane was once the
outside of the original prokaryote. In a mitochondria it gets
folded on the inner membrane to increase cell surface.
Mitochondria would have arisen from a bacteria that could
use oxygen to aerobically digest organic material.
ii. For chloroplasts – the prokaryote would have been a
photosynthetic and likewise would have a double membrane.
b. Chloroplasts and mitochondria have their own circular DNA
i. If they originated as an independent prokaryote, then would
have DNA
c. Chloroplasts and mitochondria have their own ribosomes and can
make their own proteins independent of the rest of the cell.
i. Also they can make their own proteins – ribosomes are
where proteins are made because their cells were once
independent.
d. Chloroplasts and mitochondria can reproduce inside of the cell to
increase their numbers when more energy is needed.
i. It is advantageous to be able to increase the number of
chloroplasts or mitochondria to improve efficiency of
capturing or processing energy.
5. Define the theory of natural selection. Explain how the following studies
provide specific evidence supporting Darwin’s theory of natural selection
and evolution.
a. Fossil record
i. Evidence of organisms trapped in different layers of rock
corresponding to different time periods –
ii. We use this to build patterns of evolution and link organisms
to ancestors
iii. If organisms are soft bodied, we have to speculate – with
bacteria, we don’t get much evidence until they were
prevalent enough to leave residues in the form of the mats
(stromatolites)
b. Geologic record
i. Gives evidence of conditions in different areas at different
times
ii. Match organism evidence to time periods to see how
organisms matched their environment
iii. Consider plate tectonics that also caused changes (i.e. you
can find evidence of an ocean on top of a mountain)
c. Comparative anatomy –
i. Similar anatomy
1. Arms of human
2. Leg of dog
3. Wing of bat
4. Flipper of whale
5. All of the above are made from comparable structures
d. Comparative embryology
i. In the womb or egg we all look alike –
ii. There is evidence of pharyngeal gill slits in mammals
iii. A tail
e. Molecular evidence
i. Comparing DNA
ii. We have the same proteins for basic metabolic activities as do
bacteria
6. Be able to describe the types of selection as shown in this picture and
describe an example of a population that has experienced each kind of
selection –
7. Complete this concept map:
8. Be able to match organisms to the 5 main kingdoms: Plantae; Fungi;
Protista; Monera; Animalia
9. Additional Vocabulary – be able to define, use in context, or match each
word with its correct definition
a. Natural selection – mechanism by which those organisms that are
best able to survive are more apt to reproduce and pass their genes
onto offspring.
b. Artificial selection – humans control the traits that are selected and
therefore only specific genes are passed on
c. Descent with modification – over time organisms change – as we
descend we change
d. Biogeography – study of distribution of organisms based on location
and geography
e. Homologous structures – structures that have a similar origin and
structure – for example – wing of bird, arm of human, leg of lamb
f. Vestigial organs – appendix – things we don’t use fully anymore but
are still there
g. Comparative anatomy
h. Comparative embryology
i. Molecular biology
j. Gene pool – collection of all genes available in a population
k. Microevolution – small chemical changes or changes that occur in a
small population in a short time frame
l. Macroevolution – the changes that are obvious and lead to
speciation, etc…
m. Genetic drift – random changes that occur over time – lead to
temporary fluctuations in types
n. Bottleneck effect – a catastrophic or cataclysmic event wipes out a
large segment of the population so that what is left over might be a
narrowed gene pool and that population might evolve differently
(could be disruptive or directional selection too)
o. Gene flow – when a group of individuals moves into an area they
may bring a variation of gene pool bringing in different distributions
of genes.
p. Founder effect – when a population moves to an area they may have
a specific set of genes that is then magnified because they are the
new founding population for that area (i.e. the blue people of the
Appalachians)
q. Mutations – Changes in DNA that might lead to a genetic change and
ultimately a new version of a trait
r. Fitness
s. Differential reproductive success
t. Species
u. Biological species concept
v. Prezygotic barrier
i. Temporal isolation
ii. Habitat isolation
iii. Behavioral isolation
iv. Mechanical isolation
v. Gametic isolation
w. Postzygotic barrier
i. Hybrid inviability
ii. Hybrid sterility
iii. Hybrid breakdown
x. Geographic isolation
y. Adaptive radiation
z. Gradualism
aa. Punctuated equilibrium
bb.
Protobiont
cc. Bacteria
dd.
Archaea
ee. Thermophiles
ff. Halophiles
gg. Acidophiles
hh.
Methanogens
ii. Cyanobacteria
jj. Prokaryotes
kk. Eukaryotes
ll. Endosymbiosis
10.Complete the following diagram from Chapter 18 – by identifying the key
characteristic that distinguishes one group from the next: