1) Which of the following best describes the evolution of giraffe’s long neck by
ID: 277307 • Letter: 1
Question
1) Which of the following best describes the evolution of giraffe’s long neck by natural selection?
A) Ancestors of giraffes wanted to evolve long necks to reach the leaves on high branches. The offspring of those giraffes inherited that wish and grew longer necks.
B) Ancestors of giraffes kept stretching their necks to reach the leaves on high branches. Their necks got longer throughout their life, which allowed them to survive and reproduce better than the others in the population who did not stretch their necks. Offspring in the next generation inherited that acquired trait.
C) Ancestors of giraffes did not need long necks to survive, but random changes in allele frequencies in the population resulted in more offspring inheriting the long neck genes.
D) Ancestors of giraffes that happened to be born with long neck genes were able to reach the leaves on high branches, which allowed them to survive and reproduce better than the others in the population. More offspring with long neck genes were born in the next generations.
2) Which of the following best describes the fitness of organisms?
A) The probability of organisms killing their competition before being killed
B) How well the organisms survive and reproduce in an environment
C) How fast/far the organisms spread to a new environment
D) How strong and healthy the organisms are
3) In an experiment, brown beetles were painted green with non-toxic paint. Green beetles in a green environment are less likely to be spotted by birds and eaten. Offspring of painted parents are brown, just like their parents before they were painted. Which of the conditions of Natural Selection is not met here?
A) Phenotypic Variation: There are no observable difference in beetles
B) None: This population meets all the conditions and will undergo natural selection
C) Varying Fittness For Each Phenotype: Being painted did not provide a selective advantage for those beetles
D) Heritability: The painted-on body color was an acquired characteristic that would not be passed down from parent to offspring
4) How does the mean relative fitness change from one generation to the next in response to selection, assuming the population is not in equilibrium and the relative fitness of each genotype does not change? (hint: try calculating the expected mean relative fitness of the future generation in the example given in the slides)
A) Mean fitness may go up or down between generations
B) Mean fitness decreases from one generation to the next
C) Mean fitness stays constant from one generation to the next
D) Mean fitness increases from one generation to the next
5) You observe a herd of Banthas in the desert of Tatooine. Their tail length is controlled by a single gene where dominant T1 allele and recessive T2allele code for long and short tail, respectively. Table below shows the current and expected future genotype frequencies in this population. Based on these numbers, which phenotype does natural selection favor in this environment?
A) Short tail
B) Neither phenotypes are favored
C) Long Tail
D) Both phenotypes are equally favored
6) You encounter a population of Darwin’s finches, in which you record many finches with either very large or very small beaks, but very few have medium-sized beaks. Which type of selection do you expect to detect in this population?
A) Balancing selection
B) Frequency-Dependent selection
C) Disruptive Selection
D) Directional Selection
A) Ancestors of giraffes wanted to evolve long necks to reach the leaves on high branches. The offspring of those giraffes inherited that wish and grew longer necks.
B) Ancestors of giraffes kept stretching their necks to reach the leaves on high branches. Their necks got longer throughout their life, which allowed them to survive and reproduce better than the others in the population who did not stretch their necks. Offspring in the next generation inherited that acquired trait.
C) Ancestors of giraffes did not need long necks to survive, but random changes in allele frequencies in the population resulted in more offspring inheriting the long neck genes.
D) Ancestors of giraffes that happened to be born with long neck genes were able to reach the leaves on high branches, which allowed them to survive and reproduce better than the others in the population. More offspring with long neck genes were born in the next generations.
2) Which of the following best describes the fitness of organisms?
A) The probability of organisms killing their competition before being killed
B) How well the organisms survive and reproduce in an environment
C) How fast/far the organisms spread to a new environment
D) How strong and healthy the organisms are
3) In an experiment, brown beetles were painted green with non-toxic paint. Green beetles in a green environment are less likely to be spotted by birds and eaten. Offspring of painted parents are brown, just like their parents before they were painted. Which of the conditions of Natural Selection is not met here?
A) Phenotypic Variation: There are no observable difference in beetles
B) None: This population meets all the conditions and will undergo natural selection
C) Varying Fittness For Each Phenotype: Being painted did not provide a selective advantage for those beetles
D) Heritability: The painted-on body color was an acquired characteristic that would not be passed down from parent to offspring
4) How does the mean relative fitness change from one generation to the next in response to selection, assuming the population is not in equilibrium and the relative fitness of each genotype does not change? (hint: try calculating the expected mean relative fitness of the future generation in the example given in the slides)
A) Mean fitness may go up or down between generations
B) Mean fitness decreases from one generation to the next
C) Mean fitness stays constant from one generation to the next
D) Mean fitness increases from one generation to the next
5) You observe a herd of Banthas in the desert of Tatooine. Their tail length is controlled by a single gene where dominant T1 allele and recessive T2allele code for long and short tail, respectively. Table below shows the current and expected future genotype frequencies in this population. Based on these numbers, which phenotype does natural selection favor in this environment?
A) Short tail
B) Neither phenotypes are favored
C) Long Tail
D) Both phenotypes are equally favored
6) You encounter a population of Darwin’s finches, in which you record many finches with either very large or very small beaks, but very few have medium-sized beaks. Which type of selection do you expect to detect in this population?
A) Balancing selection
B) Frequency-Dependent selection
C) Disruptive Selection
D) Directional Selection
Genotype Current frequencies Expected future frequencies 110.4 T1T 0.615 0.308 0 07-7 0.640 12 0.320 T2T2 0.040Explanation / Answer
1.
The correct answer is option (D).
Natural selection by Charles Darwin suggests that randomly present phenotypes are selected over other phenotypes which help in the better survival. Later on, the favorable phenotypic traits are passed on to the next generations making its prevalence prominent. So, option (d) describes the natural selection in best way.
2.
The correct answer is option (B).
The survival of the fittest explains how well an organism is able to survive competition and reproduce in an environment. Therefore the correct answer is option (B).
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.