BIOL 1510 Chapter Notes - Chapter 23: Disruptive Selection, Secondary Sex Characteristic, Frequency Distribution

60 views2 pages

peachgrasshopper931

13 Sep 2016

School

Department

Course

Professor

For unlimited access to Textbook Notes, a Class+ subscription is required.

Document Summary

Microevolution- a change in allele frequencies in a population over generations. There are 3 mechanisms can cause allele frequency change: Natural selection out of these constantly improves the match between organisms and their environment. Genetic variation- di erences among individuals amongst the composition of their dna this happens for many reason within of introns (lye between exons) some variations occurs not just because of genetics but also environmental factors too. Ex: body builder and how they can alter their shape. Neutral variation- di erence in dna sequence that do not give an advantage or disadvantage note: gene duplication that does not have a serious e ect can persist over generations and allows mutations to accumulate. Is for populations that do not evolve and remain consist over generations. This means that mating occurs randomly and all male and female matings are alike. that means too that allele and genotype frequency will remain the same.

Related Questions

Q1. What are alleles?Different forms of the same gene.Different genes.The different characteristics of an organism.Genes found only in humans.Q2. If you add up the frequency of homozygotes + the frequency of heterozygotes for one gene (i.e. at one locus) in a population, what number do you get?Q3. People who are heterozygous for the sickle-cell allele:Are susceptible to malaria but not sickle-cell anemia.Are susceptible to sickle-cell anemia but not malaria.Are not susceptible to either sickle-cell anemia or malaria.Are susceptible to both sickle-cecell anemia and malaria.Q4. In the case study in this lab, which genotype is represented by "2pq" in the Hardy-Weinberg equation?Homozygous HbAHomozygous HbSHeterozygous HbA/HbSNo specific genotypeQ5. Suppose that, in an isolated village, the proportion of individuals that have sickle-cell anemia is 0.1 (or 1 of every 10 people). What proportion of the population should be sickle-cell carriers, according to Hardy-Weinberg expectations?Q6. When you simulated the elimination of malaria at the beginning of the lab, once the allele frequencies stabilized, what was the frequency of the HbA allele?Q7. When you investigated regional differences, what was the frequency (over many generations) of the HbS allele in the village in the "slightly wet" part of Africa?Q8. What is the number of deaths due to sickle-cell anemia in a region without mosquitoes expected to be?Very lowVery highModerateRelated to the frequency of malaria allelesQ9. As long as there are multiple alleles of a gene in a population, why will the frequencies of the alleles always change over time?Because natural selection changes all allele frequencies in populations over time.Because genetic drift causes random fluctuations of allele frequencies in populations.Because diseases will eliminate some of the alleles, generating fluctuations in their frequencies.Because allele frequencies fluctuate before the alleles eventually become fixed.Q10. Imagine a huge population with a gene that has ten functionally equivalent, neutral alleles. A small but genetically representative group of individuals from the big population is transported to an island, forming a small population. Which of the statements below best describes what will likely happen over time, and why?Because natural selection doesn't act on neutral alleles, the frequencies in the two populations should remain the same over time.Genetic drift will cause one allele to first become fixed in the island population, and later to become fixed in the original, large population.Genetic drift will result in the allele frequencies of the two populations diverging over time, with alleles being lost sooner in the island population.The allele frequencies of the two populations will change similarly due to a combination of genetic drift natural selection.

indigosnake469

Which of the following provides evidence for evolution?

All of these answers are correct

Comparing DNA sequences between species

Looking at the geographic distribution of similar species

Analyzing transitional fossils

Which one of the following statements is true?

Natural selection works on non-heritable traits.

Mutations only give rise to harmful traits.

Natural selection works on variation already present in a population.

Individuals evolve through natural selection.

Which one of the following can create new alleles?

Which of the following is true concerning evolution?

An individual can evolve

Genetic drift is a non-random part of natural selection

An organism's fitness is determined by how long it survives

Natural selection occurs through a change in allele frequency

All living things need carbon. How does carbon enter the living portion of an ecosystem?

Atmospheric carbon dioxide taken in by photosynthesis.

Atmospheric carbon dioxide taken in by soil bacteria.

Elemental carbon taken in by plant roots.

Elemental carbon taken in by cellular respiration.

Elemental carbon taken in by cellular transpiration.

The burning of fossil fuels:

Releases excess carbon dioxide into the atmosphere.

Removes pollutants from the atmosphere.

Was developed by scientists to combat global climate change.

Has no effect on the carbon cycle.

Is good for the environment

__________ conducts water and dissolved minerals from the __________ to the ___________.

Phloem; roots; shoots

Xylem; roots; shoots

Phloem; shoots; roots

Xylem; shoots; roots

What is a disadvantage of growing traditional crops such as corn, soy or sugar cane for making biofuel?

they require lots of land and fresh water

they take carbon dioxide out of the atmosphere

they release oxygen into the atmosphere

they release water through their stomata

______ is the source of the oxygen gas released by a photosystem.

Through what structure(s) do plants obtain most of their water?

44.Why donât similar genotypes always produce the same phenotype?

A. Parent alter their phenotype and pass on this phenotype to progeny

B. Phenotype is the product of many environmental influences

C. Genetic variations of ADH enzyme produce the same phenotype

D. Animals display different phenotypes dependent on diet, not genotype

46.Which of the following attributes has the least effect on the contribution an individual makes to the gene pool of the next generation?

A. spas of mating privileges

B. more efficient at obtaining food

C. produces more offspring

D. camouflage from predators

47.âUntil the agricultural evolution 10,000 years ago, people used to live in small populations with little gene flow between them. That is the best situation for rapid evolution.â said Sewall Wright. one of the founders of population genetics. This conclusion on gene flow conflicts with Hardy Weinberg equilibrium, which states that no gene flow means

A. natural selection

B. no evolution

C. no random mating

D. no genetic drift

58 Larval flies (maggots) express the Ubx gene in all of their segments, and thereby lack appendages. If this same gene continued to be expressed throughout subsequent developmental stages, except in the head region, and if the result was a fit, sexually mature organism that still strongly resembled a maggot, this would be an example of

A. homochrony

B. exaptation

C. paedomorphosis.

D. adaptive radiation

raspberrymole848

BIOL 1510 Chapter Notes - Chapter 23: Disruptive Selection, Secondary Sex Characteristic, Frequency Distribution

Document Summary

Get access

Related Documents

BIOL 1510 Lecture Notes - Lecture 2: Frequency-Dependent Selection, Disruptive Selection, Sickle-Cell Disease

BIOL 112 Chapter 23: Chapter 23 The Evolution of Populations

BISC 121Lg Chapter Notes - Chapter 23: Secondary Sex Characteristic, Intron, Microevolution

Related Questions