Chap 13/14
"You get it from your father"
Heritability
"You get it from your father"
Heritability
What is the difference between a genotype and phenotype?
Phenotype- Observable traits as a result of differing genotypes.
Who first proposed the theory of evolution?
Charles "Fit-Daddy" Darwin
Describe the difference between bottleneck, the founder effect/inbreeding.
What are all of these an example of?
Bottlenecking refers to reduction in population size reducing genetic diversity.
Founder effect/inbreeding describes a small number of individuals starting a new population (by arrival on a new island)
Genetic Drift
Describe the conditions on earth 4 billion years ago
Oxygen free atmosphere
Rains washed mineral salts into pools to run off
Volcanoes and meteorites caused an atmosphere made of gases
Describe the difference between the terms gene, locus, and allele.
A gene refers to a unit of heritable genetic information which codes for a molecule to serve a function.
A locus is the specific location of a gene on a particular chromosome (which chromosome and where exactly)
An allele describes alternate forms of a gene that can be expressed (variant forms of the same gene).
In your own words, describe the logical reasoning as to how evolution works.
(A brief answer will suffice, nothing fancy or intricate is required but knowing how essay questions are graded, the more buzzwords used the better)
Example of a sufficient answer:
"Environmental pressures exerted on a species select for certain traits of that species which express higher fitness"
Even this is more detail than required. Understand the concept of better suited individuals will reproduce more, and be selected for in higher frequencies than those with less survivable traits.
Describe the three different patterns of natural selection and draw out their bell curve implications.
2) Stabilizing- the extremes of the graph are pushed downwards, the "normal" is selected for
3) Disruptive- The "normal" is pushed downwards, the extremes are now selected for.
What are 3 possible sources of life's building blocks?
Lightning fuelled atmospheric reactions
Reactions which took place at deep sea hydrothermal vents
Meteorites from space
(Bonus points awarded if the answer contains a joke about Michael Bay directing this process)
Match the type of mutation to the gene sequence it can be observed in, the gene sequence is normally ASDFZXC, 56789 is a sequence on a neighboring, nonhomologous chromosome:
a) Inversion 1) ASDFZXCXCXC
b) Deletion 2) ASDF56789
c) Duplication 3) ZXC
d) Translocation 4) ASZFDXC
a) = 4)
b) = 3)
c) = 1)
d) = 2)
Describe the difference between analogous structures and homologous structures.
Which one is evidence of a common ancestor?
Analogous structures refers to similar structures that evolved independently in different species.
Homologous structures refers to similar body parts that appear different when observed, but evolved from a common ancestor.
https://www.youtube.com/watch?v=YHUYfWp7UPo
Match the mechanisms of reproductive isolation to their examples:
1. Temporal isolation 2. Mechanical isolation 3. Ecological isolation 4. Behavioral isolation 5. Gamete incompatibility 6. Hybrid inviability 7. Hybrid sterility
A. Mariah beetles live and mate in trees, while zephyr beetles live and mate on the ground.
B. A perlin is the result of mating between two birds, a peregrine falcon and a merlin, but can’t produce viable gametes (egg, sperm).
C. Genitalia of damselflies and dragonflies are not compatible and do not allow for mating.
D. Two types of wild cattle mate (okapis and okanis), but the offspring can’t evade either animal’s usual predators.
E. Northern spotted owls mate in the spring, while Grey’s owls mate in the fall.
F. Two similar species of frogs that live in the same area have dissimilar mating calls.
G. Sea urchins do not mate, but rather release sperm and eggs into the ocean. Although sperm and eggs from Red Sea urchins and Purple Spiked urchins will come into contact with each other, they will not fuse to form a zygote.
1) = E)
2) = C)
3) = A)
4) = F)
5) = G)
6) = D)
7) = B)
Name the organism which most likely produced oxygen which accumulated into the atmosphere?
What major event was this responsible for in creating eukaryotes?
Cyanobacteria
Life forms were now capable of inhabiting only aquatic environments to being able to inhabit dry land.
Describe codominance.
Which blood type exhibits observable codominance?
Which blood type is recessive?
(Insufficient answers may be rewarded half points. If half points rewarded, can be redeemed here)
Someone says their AB blood is homozygous because "both alleles are dominant you doofus... duh." Why is this incorrect?
Codominance describes two alleles being both fully expressed in heterozygous individuals.
AB is an observable codominant expression.
OO
You get to rub it in their face when you explain that homozygotes need to express the SAME allele, two dominant, but DIFFERENT alleles cannot be "homozygous."
https://www.youtube.com/watch?v=YHUYfWp7UPo
Describe the difference between morphological convergence and morphological divergence.
Are the wings of insects and birds an example of morphological divergence?
A species of bird has been observed to have different beak length within the same species, shorter beaks are used for picking up berries and longer beaks are used to penetrate tough seed shells, is this an example of morphological divergence?
Convergence describes traits developed similarly and serving similar functions in different species, evolving independently at different points in time.
Divergence describes the change of the body form through time to fit different environments and functions evolving from a common ancestor.
Convergence
Divergence
Explain how malaria and sickle- cell anemia are part of a balanced polymorphism. What are the selective pressures acting on the different alleles?
The answer must involve describing why homozygous recessive do not survive due to having sickle cell anemia at a young age, why homozygous dominant do not survive due to contracting malaria, and heterozygotes needing to constantly recycle and regenerate new RBCs, in essenece destroying malaria infected cells.
Describe Miller-Urey's experiment and specifically, what was its purpose?
The purpose was to prove that from these "inert" chemicals, compounds capable of life could form. It explained the origin of compounds necessary to build life forms.
Team question:
In cocker spaniels, black coat color (B) is dominant over red (b) and solid color (S) is dominant over spotted (s). In other words, b and s are the recessive alleles. If two heterozygous (Bb Ss) dogs are crossed, what will the ratio of phenotypes in the offspring be? This is an example of a dihybrid cross (producing F2 offspring). Be sure to show your work (a Punnett Square)
Written out on the board.
Briefly describe the process of radiometric dating using Carbon-14 as an example.
Carbon-14 is an isotope of carbon found in some fossils. Every half life, half of the Carbon-14 will decay to the more stable Nitrogen-14. Because the half life of carbon 14, an isotope of carbon, has been scientifically determined (5370 years), it is possible to measure the ratio of C14 to the ratio of N14 to determine how many half lives have passed.
)Notes say C14-->C12, when my study guide was corrected it was corrected to C14-->N14?)
What are the 5 conditions for genetic equilibrium?
What is the hardy Weinberg formula?
Two alleles are seen in populations in Ireland for binding of iron to blood hemoglobin-one results in excessive binding (b), and is recessive and leads to a disease state in individual who are homozygous, the other results in normal iron binding and is dominant (B). The relative frequency of B, the “normal” allele, is 0.78. What is the frequency of the b allele, and what percentage of individuals would you predict will have the disease state (that is, be bb)?
2) Random mating
3) No mutations to change allele frequency
4) No migration/gene flow
5) No natural selection
p^2+ 2pq + q^2= 1
1-.78= .22, 4.84%
You have sampled a population in which you know that the percentage of the homozygous recessive genotype (aa) is 49%. Using that 49%, calculate the following: A. The frequency of the "aa" genotype. (0.49) B. The frequency of the "a" allele. C. The frequency of the "A" allele. D. The frequencies of the genotypes "AA" and "Aa.
A) .49
B) .7
C) .3
D) .51