Answer:
natural selection ; homologous
The population of birds with large beaks will increase on the island (1st listed) ; The trait for large beaks will be passed on to future generations through natural selection. (3rd listed)
B) 80 /200
Step-by-step explanation:
Giraffes evolved over many generations to have long necks. Giraffes that had longer necks were more likely to survive than giraffes with shorter necks because they had better access to food. This is an example of natural selection / survival of the fittest.
(the "fittest" [most beneficial/practical] trait is surviving and getting "selected" by nature)
Giraffes are also vertebrates, like humans. In fact, despite their different neck sizes, humans and giraffes have exactly seven vertebrae bones in their neck. This similarity suggests human and giraffe necks are homologous [structures]
>>next image
...' What are two ways the decrease in seed availability will affect the population of birds on the island?'
The population of birds with large beaks will increase on the island.
[This is the concept of natural selection / survival of the fittest, they have the most abundant resource [because they are able to eat what is abundant on the island, compared to smaller birds that have a larger decrease in food availability] ]
The trait for large beaks will be passed on to future generations through natural selection.
[If these birds / and this trait survive, they will be able to have offspring [future generations]. Birds with a low survival percentage will be less successful in mating, and will likely not produce the same quantity of offspring that will carry on their traits to future generations.]
>>next image
frequency of an allele:
population: 100
frequency recessive [homozygous bc 2 same recessive alleles]: 25 (tt)
frequency dominant homozygous: 45 (TT)
frequency heterozygous dominant: 30 (Tt)
total alleles: 100 [our population] times 2
100 · 2 = 200
total alleles: 200
number of times we have [dominant] T:
30 from each heterozygous dominant (Tt)
2 · 45 (TT has two T's) = 90 from homozygous dominant
30 + 90 = 120
number of times we have [recessive] t :
30 from each heterozygous dominant (Tt)
2 · 25 (tt has two t's) = 50 from each homozygous recessive
30 + 50 = 80
So, we know that the frequency of recessive allele [t] is 80 / 200
[80 out of 200]
So, option B) 80 / 200 is correct
(this = 0.4)
(and dominant [T] is 120 / 200; I say this to show that recessive frequency and dominant frequency are calculated the same way!!)
(this = 0.6)
hope this helps!! (this took me a long time to write so please do read it thoroughly!!)