BIOL 191 EXAM 1 QUESTIONS WITH
CORRECT ANSWERS
What are the five Hardy-‐Weinberg conditions ? - verified answers;
What is the difference between the founder effect and the bottleneck effect? - verified
answers; The bottleneck effect is a something that happens that reduces a population such as
a disaster. If there is a drought then only some population will be able to survive. A founder
effect is an event of a small population finding a new population to settle down in. The main
difference in the two is that bottleneck effect is because something drastic has changed a
population and the founder effect is to find a new region or environment.
What are the three main conditions necessary for natural selection? - verified answers; 1.
Variation
2. Competetion
3. Reproduction
In your own words, explain the biological species concept. - verified answers; The biological
species concept is the potential of interbreeding but they need to be able to produce healthy
fertile offspring. However, they are re productively isolated and cannot reproduce with other
groups.
What are two problems with the biological species concept? - verified answers; 1.
Hybridization- for example in class we talked about a donkey and hoarse reproducing and
having a mule. Although they were able to reproduce and interbreed. Their offspring now was
a hybridized mule who cannot reproduce.
2. Asexual reproduction- a single organism is not reproducing sexually they are reproducing
identical copies. This hurts the concept because there is no sexual reproducing happening
between 2 organisms.
, What is the difference between pre and post-‐zygotic isolating mechanisms? - verified
answers; Prezygotic isolating mechanisms prevent successful fertilization, while post zygotic
isolating mechanisms result in the production of a zygote, but that zygote can be inviable,
infertile, or weak.
What is the difference between allopatric and sympatric speciation? - verified answers;
Allopatric speciation occurs when there is geographical isolation, while sympatric speciation
occurs within the same geographical region.
Suppose a population of horses has a gene for coat color, with two alleles, B and b. The
frequency of B alleles in the population is 0.25. What is the frequency of the b allele?
a)0.06b)0.25c)0.5d)0.75e)1 - verified answers; 0.75
In the United States, most Angus cows are black (BB or Bb), with very few being red (bb). A
population of Angus cows has 75red cows and 150black cows. Assume complete dominance,
so that black is dominant to red. Given this information, what is the genotypic frequency of
BB?a)0.18b)0.33c)0.42d)0.49e)0.58 - verified answers; 0.18
What would be the frequency of the heterozygotesin the population from the previous
question?a)0.18b)0.33c)0.42d)0.49e)0.58 - verified answers; 0.49
What is true of natural selection?
a)Natural selection is a random process.
b)Natural selection creates beneficial mutations
.c)Mutations occur at random; natural selection can preserve and distribute beneficial
mutations
.d)Mutations occur when directed by the good of the species; natural selection edits out
harmful mutations and causes populations to adapt to the beneficial mutations. - verified
answers; C
CORRECT ANSWERS
What are the five Hardy-‐Weinberg conditions ? - verified answers;
What is the difference between the founder effect and the bottleneck effect? - verified
answers; The bottleneck effect is a something that happens that reduces a population such as
a disaster. If there is a drought then only some population will be able to survive. A founder
effect is an event of a small population finding a new population to settle down in. The main
difference in the two is that bottleneck effect is because something drastic has changed a
population and the founder effect is to find a new region or environment.
What are the three main conditions necessary for natural selection? - verified answers; 1.
Variation
2. Competetion
3. Reproduction
In your own words, explain the biological species concept. - verified answers; The biological
species concept is the potential of interbreeding but they need to be able to produce healthy
fertile offspring. However, they are re productively isolated and cannot reproduce with other
groups.
What are two problems with the biological species concept? - verified answers; 1.
Hybridization- for example in class we talked about a donkey and hoarse reproducing and
having a mule. Although they were able to reproduce and interbreed. Their offspring now was
a hybridized mule who cannot reproduce.
2. Asexual reproduction- a single organism is not reproducing sexually they are reproducing
identical copies. This hurts the concept because there is no sexual reproducing happening
between 2 organisms.
, What is the difference between pre and post-‐zygotic isolating mechanisms? - verified
answers; Prezygotic isolating mechanisms prevent successful fertilization, while post zygotic
isolating mechanisms result in the production of a zygote, but that zygote can be inviable,
infertile, or weak.
What is the difference between allopatric and sympatric speciation? - verified answers;
Allopatric speciation occurs when there is geographical isolation, while sympatric speciation
occurs within the same geographical region.
Suppose a population of horses has a gene for coat color, with two alleles, B and b. The
frequency of B alleles in the population is 0.25. What is the frequency of the b allele?
a)0.06b)0.25c)0.5d)0.75e)1 - verified answers; 0.75
In the United States, most Angus cows are black (BB or Bb), with very few being red (bb). A
population of Angus cows has 75red cows and 150black cows. Assume complete dominance,
so that black is dominant to red. Given this information, what is the genotypic frequency of
BB?a)0.18b)0.33c)0.42d)0.49e)0.58 - verified answers; 0.18
What would be the frequency of the heterozygotesin the population from the previous
question?a)0.18b)0.33c)0.42d)0.49e)0.58 - verified answers; 0.49
What is true of natural selection?
a)Natural selection is a random process.
b)Natural selection creates beneficial mutations
.c)Mutations occur at random; natural selection can preserve and distribute beneficial
mutations
.d)Mutations occur when directed by the good of the species; natural selection edits out
harmful mutations and causes populations to adapt to the beneficial mutations. - verified
answers; C
