Biology Exam 4 Study Guide

When the receptor proteins on an egg do not match the proteins on a sperm cell that is an example of

gametic isolation, which is a prezygotic reproductive barrier.

Which of the following is an example of mechanical isolation?

insects with external genitalia do not align for fertilization

Natural selection

Is the process by which individuals with more fitness produce more offspring

If many characteristics are affected by one gene, the gene is

pleiotropic.

The F2 generation of a monohybrid cross is the result of sperm fertilizing the eggs of the _____ generation.

F1

The F2 generation of a monohybrid cross is the result of sperm from the _____ generation fertilizing eggs.

F1

In a monohybrid cross, the third generation is called the ______ generation.

F2

A man is heterozygous for hemoglobin, with one normal allele for sickle cell anemia and one sickle allele. What are the chances that one of his sperm cells will have the normal allele?

50%

How could you create a transgenic plant?

Insert the gene from a different species in the vector, infect a plant cell with the new gene, and grow a plant from the cell.

What is the ratio of types of gametes of an individual that is PP

100% P

What is the ratio of types of gametes of an individual that is pp

100% p

Imagine insulin type in worms is Mendelian. You have a population of 1000 worms that are all heterozygous for the insulin gene, with the type A insulin dominant (I) to the type B insulin (i). What is the phenotype frequency of worms in this population with type A insulin?

100% type A insulin

Assume Mendelian inheritance for this question. You perform a monohybrid cross of a plant with green-pod phenotype to a plant with the yellow-pod phenotype. Green pods (G) are dominant, and yellow pods (g) are recessive. If you have 10,000 plants in the F2 generation, how many of the F2 plants do you predict will have green pods and be true breeding?

2,500

Assume Mendelian genetics for this question. You have a population of 10,000 beetles that are all heterozygous for leg length (L for Long, and l for short). What is the allele frequency for the long leg gene (L)?

50% L

In a Mendelian monohybrid cross of a pea plant with dominant tall (T) plants with a plant with recessive short (t) plants, how many offspring of 100 plants in the F2 generation would you predict will be homozygous recessive?

25

You start with a population with an allele frequency of 25% G and 75% g, and the individuals breed randomly and there is no selection for or against G or g. After 100 generations, you would expect the allele frequency to be

25% G and 75% g.

You perform a monohybrid cross of plants with red flowers (RR) and plants with white flowers (rr) in a species where flower color has incomplete dominance resulting in pink flowers. You continue to cross the F1 generation plants with each other to generate the F2 generation. What phenotypic ratio of flower color would you predict in the F2 generation?

1 red: 2 pink: 1 white

Imagine hemoglobin type in fish is Mendelian. You have a population of 1000 fish that are all heterozygous for the hemoglobin gene, with the type A hemoglobin dominant (H) to the type B hemoglobin (h). What is the phenotype frequency of fish in this population with type B hemoglobin?

0 % type B insulin

LO 4.4) Plant height is Mendelian. Tall plants are dominant to short plants. In a monohybrid cross of a tall plant to a short plant, the F2 generation would have a phenotype ratio of

3 tall plants : 1 short plant

Plant height is Mendelian. Tall plants are dominant to short plants. In a monohybrid cross of a tall plant to a short plant, the F2 generation would have a phenotype ratio of

3 tall plants : 1 short plant

Assume Mendelian genetics for this question. You have a population of 1,000 fish. Long tails (L) are dominant. Short tails (l) are recessive. 50% of the fish are homozygous recessive, and 50% are homozygous dominant. What is the phenotype frequency of this population?

50% Long tails

What is the ratio of types of gametes of an individual that is Pp

50% P and 50% p

Imagine a monohybrid cross studying stem length. The tall phenotype (T) is dominant; and the short phenotype (t) is recessive. You would predict that the plants in the F2 generation would be

50% heterozygous.

Beetles are diploid. If you have a population of 1000 beetles that are all heterozygous for color, with dark dominant to light color, what is the allele frequency?

50% light allele

If you cross a homozygous dominant yellow pea plant with a homozygous recessive green pea plant in the P generation, and self cross the offspring in the F1 generation to generate the F2 generation, how many yellow peas would you expect out of the 100 peas in the F2 generation

75 yellow of 100

If you have a population of humans with 15 homozygous dominant people, 25 heterozygous people, and 10 homozygous recessive people, what is the phenotype frequency for the dominant phenotype?

80%

Which of the following is NOT evidence for evolution

Animals that learn behaviors from their parents

The major structural component of a plant is cellulose, which is a carbohydrate made of carbon, hydrogen, and oxygen m. The matter in cellulose comes from

Carbon dioxide and water

In a monohybrid cross, the offspring of the first two plants are the _________ generation.

F1

Which of the following is always true?

Dominant alleles appear in the phenotype even if they are only one of two copies.

(LO 4.2) Assume Mendelian genetics for this question. Huntington's disease is caused by a mutation in the huntingtin gene. The mutated version of the huntingtin gene (H) is dominant, and the non-mutated version (h) is recessive. Which genotypes will have Huntington's disease?

HH and Hh only

There is an island with plants that have light green leaves. There also are light green insects that live on the leaves and birds that hunt the insects by looking for them on the island. There is a mutation in the plants so that they now have dark green leaves. The mutation makes the plants able to make more sugar from carbon dioxide by photosynthesis, so after a few generations most of the plants have dark green leaves. What would this most likely do to the population light green insects?

It would decrease the fitness of the light green insects, resulting in natural selection against them.

In a monohybrid cross, the first two plants are the _____ generation.

P

Which of the following is a postzygotic reproductive barrier

Reduced hybrid viability

The carbon that ends up in glucose and other organic molecules in plants enters through

The leaves as the gas carbon dioxide

Assume Mendelian genetics for this question. You have a population of 280 beetles with red color dominant to black color. 20% of the alleles are red and 80% are black. Which one of the following is true?

There will be more black beetles than red beetles.

How are artificial selection and natural selection similar

They both lead to changes in allele frequency in a population

When a random 5% of a population of salamanders floats on a log to a new island that did not have any salamanders, and starts a new population, it is an example of

a founder effect

A population of turkeys starts with 10,000 birds, and a frequency of the short-feather allele of 10%. One day a random 100 turkeys run off to another set of woods and do not breed with the original population any more. The new population that originated with the 100 turkeys that ran off has a short-feather allele frequency of 75%. This is an example of

a founder effect.

Mutations in the gene that codes for the enzyme phenylalanine hydroxylase cause the human disease phenylketonuria. The symptoms include mental retardation, reduced hair pigmentation, reduced skin pigmentation, abnormal gait and abnormal posture. This is an example of

a pleiotropic trait.

Which type of disease would be a bad target for gene therapy?

a polygenic disease

A genetically dominant allele will always

appear as the phenotype if there is at least one dominant allele.

On average, in a Mendelian monohybrid cross the F2 generation has plants that

are 75% dominant phenotype and 25% recessive phenotype.

Under the morphological species concept, a species is a group of organisms that

are physically similar.

A plant with red flowers is crossed to a plant with white flowers. The F1 generation is all pink and the F2 generation has plants with that are 1 red-flower plant : 2 pink-flower plants : 1 white-flower plant. This is an example of

incomplete dominance.

Imagine beetles living in a mostly brown environment. Some beetles have a dominant color allele that makes them green (G), and some have the recessive allele that makes them brown (g). Birds hunt the beetles visually and can see the green beetles on the background of brown dirt. In years when there are more birds you would predict that the

green (G) allele frequency would decrease.

Assume Mendelian genetics for this question. Green pod color (G) is dominant to yellow pods (g). If a gg plant is crossed to a GG plant in the parental generation, the F1 plants will have a ____________ phenotype, and a ______ genotype.

green pod, Gg

Individuals with more fitness

have more viable, fertile offspring in the next generation.

Assume dog coat color is Mendelian. If a dog has a Bb genotype for coat color and a brown coat, and another dog has a bb genotype for coat color and a black coat, how would you describe the Bb genotype?

heterozygous

In a monohybrid cross, all of the plants of the F1 generation are _________.

hybrids

A subset of a population with a unique allele survives better than the rest of the population and contributes more of that allele to the next generation. In other words, the frequency of the unique allele increases in the next generation due to natural selection. Compared to individuals without this allele, individuals with this allele have

more fitness.

Which of the following is a mechanism of adaptive evolution, where the alleles of the fittest individuals will become more frequent in subsequent generations?

natural selection

If a characteristic is affected by many different genes, it is

polygenic

Assume Mendelian genetics for this question. If T is for the dominant tall-plant trait and t is for the recessive short-plant trait, then which of the following would be the possible genotype(s) of short plants?

only tt

If you claim two plants are the same species based on the basis of them having a common ancestor, you are using the _____________ definition of a species.

phylogenetic

(LO 4.3) Eye color is determined by many genes. This aspect of eye color is an example of

polygenic inheritance.

Scientists currently believe that hair color is determined by many genes. This aspect of hair color is an example of

polygenic inheritance.

Using the phylogenetic species concept, a species is a group of organisms that

share a recent common ancestor.

Which of the following is NOT evidence for evolution?

some dogs follow instructions to sit and others do not

Assume Mendelian traits are being considered in this question. Assume small size is a trait that allows mice to hide from snakes, and large size makes it hard for mice to hide. If a large population of these mice lives without snakes for many generations, then snakes move into the area, it is most likely that when snakes move into the community

the small-size allele frequency and small-size phenotype frequency will increase.

Antibiotic-resistant bacteria increase in frequency

when antibiotics kill many of the competing bacteria without killing the resistant bacteria.