Genetics
In humans, the allele for having a straight thumb is dominant to the allele for having a curved thumb. A male is homozygous dominant for straight thumbs, and a female has curved thumbs. What is the possibility that their offspring has curved thumbs?
0%
Sand Tiger Shark embryos eat each other in the womb! DNA testing recently revealed that the mystery of this baby shark cannibalism is due to embryos from different fathers competing to be born. If there are two embryos with the same father, they will eat all the others so they can both live. Which of the following is the most likely outcome of this process over time?
A) Increase the fitness of the Sand Tiger shark population.
B) Evolution of a new more advance shark species
C) Adaptive radiation resulting in several variations (subspecies) of the Sand Tiger Shark
D) The long term effects will be negative as important members of the population
A
Pea Blight, a disease in pea plant results when a plant is homozygous recessive for the trait (tt).
If two pea plant parents do NOT have Pea Blight, but have pea plant offspring with the Pea Blight, what is the genotypes of the two parents?
Tt x Tt
Which scenario is an example of speciation?
A) Houseflies from a certain region migrate and interbreed with a different housefly
B) A river separates members of a salamander population that used to occupy the same geographical area
C) A disease ravages a large fox population, killing all members that did not have a genetic resistance to the disease
D) Certain members of a human population have more offspring than others.
B
One parent is heterozygous for a certain trait (Dd). The other parent is homozygous dominant (DD) for that trait.
What is the percent chance that an offspring from this cross will be heterozygous?
50%
In every population, adaptations allow some organisms to survive and reproduce better than others is what?
natural selection
The different forms of a gene are called
alleles
When two organisms adapt in response to each other.
coevolution
A black sheep (BB) is incompletely dominant over white sheep (bb). What is the genotype and phenotype of the offspring?
(Hint: Do a Punnett square on paper.)
Bb, gray
Two or more not closely related species adapt similar traits to one another due to a similar need
convergent evolution