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amberleopard326Lv1

28 Sep 2019

Describe the theory of natural selection Which of thefollowing BEST describes the theory of natural selection? CHOOSEONE

1 The genetic make-up of apopulation gradually changes from one generation to the next.

2 Living organisms change overtime.

3 Each species produces many moreoffspring than can survive long enough to reproduce. The offspringthat do survive contain genes that are inherited from theparents.

4 There is variation among themembers of a species. Some of this variation is geneticallydetermined and so can be passed on to future generations.

5 Some individuals have genes thatincrease their chances for survival and reproduction. Theseindividuals are more likely to reproduce and pass on their genes,causing their genes to become more common in the nextgeneration.

6 There is a struggle for existenceamong the members of a population.

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bingoLv10

5 Nov 2023

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Keith LeannonLv2

28 Sep 2019

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Evolution naturally produces better features: stronger muscles,teeth and minds. Killing the weakest, evolution wipes defectivegenes out of populations.

The mutations are necessary for advance. However, they arerandom and, thus, mostly negative. Right? How does the natureeliminate them from the population?

I see that one mechanism is polygamy: male have higher mutationrates. They tend to reproduce as much as possible. Female havelower mutation rates, they couple with only with best men andcontribute much more to their offsprings. So, men generate as muchrandom solutions as possible, whereas the role of female is toconserve the best of them. This means that the most of the male(bad mutations) die unreproduced. This eliminates the bad mutationsand favours the progress of good qualities. The higher animalsstarted to form harems and tournaments over their ownership. Thisfurther fosters the elimination of weak men and profileration ofstrong genes. However, human monogamy has disabled this selectionmechanism. Best men are dedicated to only one woman. Other womencannot mix their genes with other good genes from previousgenerations. They are forced to look at the low quality men, whocarry degenerate mutations. Might be it is monogamy that makes ushuman but it implies that all genes reproduce.

Yet 100 years ago it was not a big deal since we still hadanother filter: our grandfathers were born in families that hadnormally 10 children (I am speaking about Russia) and only 2-3survived until reproduction (the population increased reallyslowly). I bet that those who survived had really good health:thanks to the bad health and immense selection pressure, thenegative mutants are eliminated immediately and populationmaintains a perfect genome (aka biologic health). Killing moreweakest in the current generation improves the health of nextgenerations.

However everything has changed during the 20th century. Theadvances in economy and medicine have almost eliminated theselection. The selection pressure has relaxed to essentially zeroso that everybody survives and leaves the same amount of offspring(and some scientists are even concerned that degradatoryindividuals leave more offsprings than the prosperous ones). Wehave even eliminated the infant mortality. We use baby incubatorsso that the people with the weakest health could survive andreproduce as normal and we are proud of it. It may sound strangebut the mutation rate has not changed at all. Does it mean that thehuman genome is in danger?

I see the situation like you have inherited a perfect mechanismand decided not recovering it from the inevitably adverse action ofentropy, that degrades it constantly. There is a constant chance,d, that every good gene is affected by a mutation. It is afraction of healthy genes that will fail passing to the nextgeneration. This will leave only (1-d) genes healthy inthe next generation. The fraction of healthy genes will melt like1, (1-d), (1-d)

Messenger RNA (mRNA)...

a) Is a structural part of a ribosome

b) Brings amino acids to DNA

c) Carries genetic information from the nucleus to the cytoplasm

d) Is a structural part of a chromosome

e) Initiates and directs chemical reactions

Mr. Potato is homozygous dominant (KK), his son, Potato Jr. is heterozygous (Kk). Based on this information, what are the possible genotypes for Mrs. Potato? (Hint: use a Punnet Square).

a) Her genotype is definitely kk

b) Her genotype is either Kk or kk

c) Her genotype is either KK or Kk

d) Her genotype is either KK, or Kk, or kk

e) Mr. Potato cannot be Potato Jrâs biological father

12. Homologous chromosomes:

a) Are members of different chromosome pairs

b) Are genetically identical

c) Carry genetic information that influences the same traits (same genes but probably different alleles)

d) Are only inherited from the mother

e) Are only inherited from the father.

âFitnessâ in an evolutionary sense, refers to an individualâs:

a) Strength

b) Reproductive success

c) Aggressiveness

d) Size

e) Age at death

The fact that individuals who possess favorable traits are more likely to survive and reproduce than those who possess less favorable traits is the basis for the theory of...

a) uniformitarianism.

b) natural selection.

c) the inheritance of acquired characteristics.

d) catastrophism.

e) the fixity of species.

Even with strong selection, genetic variation of a population can be maintained because:

a) Selection only affects one gene at a time.

b) The effects of many alleles are hidden from selection by the effects of other alleles

c) Mutation constantly adds new alleles at an extremely fast rate.

d) Populations always go extinct before their gene frequencies are dramatically altered.

e) Only a and c

Gene Flow is defined as the:
a) Production of new alleles
b) New musical group in which Adam Levine will be the leading vocalist
c) Exchange of genes between populations
d) differential reproductive success of individuals
e) Process by which a DNA base gets extracted out of the nucleus to initiate the process of protein synthesis.

The basic unit of DNA is a molecule called a: a) Nucleotide

b) Base
c) Thymine
d) Prokaryoticcell e) mRNA

How many bases code for one amino acid? a) one

b) two
c) it depends on what amino acid it is d) three
e) four

Hemophilia is a condition that affects: a) more females than males
b) more males than females
c) females and males equally

d) only children born prematurely
e) individuals with a missing portion of chromosome number 5

A clear example of directional selection is:
a) Darwin finches with deeper and thicker beaks associated to a severe drought b) Sickle cell anemia in regions in which Malaria is endemic
c) Achondroplasticdwarfism
d) Fly halteres becoming fully developed wings after modification of a hox gene e) all of the above

Meiosis is evolutionarily significant because:
a) New combination of alleles can arise through independent assortment and crossing over

22.

23.

24.

25.

26.

b) It is the mechanism by which body tissues are repaired
c) It creates somatic cells that are crucial for our body organs to maintain us alive d) It allows forensics to determine the cause of death of unidentified people
e) none of the above

Homologous chromosomes:

a) Are exact copies of each other and contain exactly the same genetic material
b) Are members of different chromosome pairs
c) Are only inherited from the father
d) carry genetic information that influences the same traits (the same genes), however, each of the homologous chromosomes can contain different versions of the same gene (different alleles).

e) carry genetic information that influences different traits because each of the homologous chromosomes contains completely different genes at very different loci

How many chromosome pairs occur in a normal human somatic cell?

a) 46 b) 23 c) 22 d) 24 e) 45

What is the scientific method? Use bullet points to describe the 4 major components.

How is a hypothesis different from a theory?

List the four major components (described during class) necessary for natural selection to occur [AKA Darwinâs Four Postulates] (PDF1-3).

27. Who was Thomas Malthus? In what way(s) Malthus was influential for Darwinâs Theory of Natural Selection? Hint: populations vs resources.

29. What amino acids are being coded for by the gene segment provided below? Nucleotide triplets and their corresponding amino acids are:
ACA= Cysteine; AAA=Phenylalanine; TGG=Threonine; CCT=Glycine; GAT=Leucine; ATA=Tyrosine; AGG=Serine; TCT=Arginine

a) Threonine, serine, glycine, tyrosine, leucine, phenylalanine, arginine, cysteine.

b) Tyrosine, leucine, glycine, threonine, arginine, threonine, serine, cysteine.

c) Arginine, cysteine, serine, glycine, threonine, leucine, phenylalanine, tyrosine.

d) Phenylalanine, leucine, tyrosine, glycine, serine, threonine, cysteine, arginine.

e) Phenylalanine, leucine, tyrosine, glycine, threonine, phenylalanine, arginine, serine.

QuestionGroup: #31 Evolution

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Which of the below statements is NOT TRUE about human evolution?

While the total number of species that existed and the relationships among hominids is still unknown, some of the extinct hominids known today, however, are almost certainly direct ancestors of Homo sapiens.

Human evolution follows the mechanisms of natural selection.

Humans evolved from biological processes that are different from the processes that caused the development of other life forms on earth.

Many of the hominid species are close relatives, but not human ancestors.

Most hominids went extinct without giving rise to other species.

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QuestionGroup: #32 Evolution2

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______________ explains the process by which traits helpful in survival and reproduction become progressively more common in a population over the course of many generations.

Secondary metabolism

Darwinian theory of evolution

Evolutionary arms race

Biodiversity

Lemarkian theory of evolution

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QuestionGroup: #33 Natural selection

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Which of the following is considered to be "the most fit "from an evolutionary perspective?

a tiger who cares for his cubs, two of who live to adulthood.

a tiger who has a harem of many tigresses and one cub.

a tiger who is successful at capturing prey but has no cubs.

a tiger who has many cubs, twelve of which live to adulthood and they subsequently have cubs of their own.

a tiger who overcomes a new disease and lives to have four cubs.

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QuestionGroup: #34 Natural selection 2

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Which of the following is NOT a process of artificial selection?

(1),(2)

(1),(2),(3)

(1) Variation of traits within individuals

(2) Variation in some inheritable traits

(3) Breeders select animals with favorable traits

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QuestionGroup: #35 Evolution & us

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For bipedal movement in primates to occur, which anatomical changes had to take place?

The spine had to have a characteristic single curve

Thigh bone slopes outward from the hip to knee, placing feet under the center of gravity

The surfaces of the joints in legs and between vertebrae are enlarged

All of these are true regarding upright bipedal movement

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QuestionGroup: #36 Evolution & us2

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Neanderthal hominoids had which of the following characteristics?

To make art

Ability to speak

Ability to speak, make art, and were bipedal

Bipedalism

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QuestionGroup: #37 CNS

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Increasing the amplitude of a sound wave does what to the sound?

increases the amplitude

increases the decibels

Increases the harmonics

Increases the volume

Increases the pitch

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QuestionGroup: #38 CNS2

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Juan Manuel Marquez delivered a knockout punch to Manny Pacquiao. Manny cannot remember events that happened before the knock-out. What is this an example of?

Alzheimer's disease

Anterograde amnesia

Psychogenic amnesia

Retrograde amnesia

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QuestionGroup: #39 PNS

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The receptor hair cells in the cochlea respond to the frequency and amplitude of sound. Which group of receptors are most sensitive to sound?

Only those receptors that we normally do not use

Those that respond to low frequencies

Receptors respond equally to all frequencies.

Those that respond to high frequencies

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QuestionGroup: #40 Smooth/skeletal

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During skeletal muscle contraction where does ATP function?

Forms the cross bridges

Attaches to myosin

Causes the thick filaments to form thin filaments

Attaches to actin

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	1 The genetic make-up of apopulation gradually changes from one generation to the next.
	2 Living organisms change overtime.
	3 Each species produces many moreoffspring than can survive long enough to reproduce. The offspringthat do survive contain genes that are inherited from theparents.
	4 There is variation among themembers of a species. Some of this variation is geneticallydetermined and so can be passed on to future generations.
	5 Some individuals have genes thatincrease their chances for survival and reproduction. Theseindividuals are more likely to reproduce and pass on their genes,causing their genes to become more common in the nextgeneration.
	6 There is a struggle for existenceamong the members of a population.