Bio Exam 4

What is a carrier? If a trait is sex-linked recessive, can both males and females be carriers? If a trait is sex-linked dominant, who can be a carrier? If a trait is autosomal dominant, who can be a carrier?

Carrier- carries a recessive allele but you do not see it [heterozygous]. Male cannot be carriers in sex-linked conditions. No carriers of autosomal dominant or sex-linked dominant

Explain how genes located on the same chromosomes may not be linked.

Crossing over provides a way to unlink genes on the same chromosome

A population of 15 birds inhabits a fairly new island. Ten of the birds are dark-brown and five of them are light brown. By chance, two of the dark brown birds and three of the light-brown birds die before producing any offspring. All of the birds in the next generation are dark brown. This change in phenotypic frequency can be attributed to _____. A. disruptive selection B. gene flow C. natural selection D. genetic drift

D

Katie has curly hair which is a dominant trait. What is her genotype? A. CC B. Cc C. cc D. CC or Cc E. Curly Hair

D

Which of the following is NOT a line of evidence for the existence of evolution? A. An insect encased in 10-million-year-old tree sap B. Fossils of the fern Glossopteris found in South America, Antartica, Australia and India C. Tail bones found in humans that have no function today D. Transcription and translation of a gene into a protein

D

Which of these make a population better adapted to its environment? A. Mutation B. Genetic Drift C. Gene Flow D. Natural Selection

D, but all result in evolutionary change.

Huntington's disease is an autosomal dominant disorder. which family member(s) has/have the disease and who can be considered a carrier for this disease? Mom (Hh), Dad (hh) Bro (Hh) A. Mom & Bro; Mom & Bro B. Dad; Mom & Bro C. Dad; No carriers D. Mom & Bro; No carriers

D. Cant be a carrier for a dominant disorder (if you have it you'll show it)

If we trace the fossil record of toothed whales (i.e. dolphins, killer whales, etc.), we see that an early, extinct ancestor walked on land (i.e. mesonychid) and a more recent ancestor walked on land and swam (i.e. Ambulocetus natans). Overall, these fossils show _____. A. How species changed over time. B. How species go extinct. C. How all species were created at the same time. D. A & B E. All of the above

D????

Compare and contrast the founder effect and population bottlenecks.

Founder effect- A small number of individuals may leave a population and become the founding members of a new, isolated population. Bottlenecks- when famine, disease, or an environmental change causes the death of a large random population, and the surviving individuals have different allele sequences than the original population

heterozygous vs homozygous

Homozygous [same-FF or ff] Heterozygous [different-Ff]

disruptive selection

Individuals with extreme phenotypes experience the highest fitness, and those with intermediate phenotypes have the lowest.

stabilizing selection

Individuals with intermediate phenotypes are most fit.

directional selection

Individuals with one extreme from the range of variation in the population have higher fitness.

Why might it not be beneficial to reestablish endangered species from small populations?

It would reverse evolution, Natural Selection

In a pedigree, what does a shaded circle indicate? Shaded square? Unshaded circle? Unshaded square?

Shaded circle- Female with specific trait Shaded square- Male with specific triat unshaded circle- unshaded square-

Divergent Evolution

Start with a common ancestor and branch out

What is radiometric dating and how has it improved the evidence of the fossil record?

The process of determining the age of the fossils from radioactive isotopes

Explain, in terms of genetic variation, why inbreeding is bad

These family relatives will share lots of the same genes so if one of these genes is faulty, there is a higher risk that their offspring will get a faulty copy from each parent and be diseased.

Why are mutations important in evolution when most mutations are harmful? In order for a mutation to become an evolved trait, in what cell types must this new allele occur?

Ultimate source of all genetic variation; source of new traits and alleles

complete dominance

a relationship in which one allele is completely dominant over another ex- red or white flower

What are vestigial structures?

a remnant structure that has lost its ancestral function (tail bone in man)

How is artificial selection distinguished from natural selection?

artificial selection- Human-made selection natural selection- New traits and alleles created by nature

Why would a characteristic such as having blue eyes change within a population overtime if this trait doesn't help or hurt an individual?

because its a recessive trait

Why are many vertebrate embryos indistinguishable during the early stages of development?

because we all shared a common ancestor

Compare and contrast the worldview before and after Darwin

before- Species were not linked in a single "family tree." They were unconnected, unrelated, and unchanged since the moment of their creation. after-

Independent Assortment

different genes independently separate from one another when reproductive cells develop.

monohybrid vs dihybrid cross

dihybrid- two traits monohybrid- one trait

dominant vs recessive

dominant(FF, Ff): Only have to have one copy of dominant allele to show the trait recessive(ff): Have to have 2 copies of recessive allele

Define evolution. Do individuals or populations evolve?

evolution: Changing populations over time populations evolve, not individuals

Why do males exhibit sex-linked recessive traits more frequently than females?

females will have two copies of the sex-linked gene while males will only have one copy of this gene. If the gene is recessive, then males only need one such recessive gene to have a sex-linked trait rather than the customary two recessive genes for traits that are not sex-linked.

Clarify the phrase "survival of the fittest."

-Reproductive success -Fitness: the relative amount of offspring of an individual with a particular phenotype, compared to the offspring output of individuals with alternative phenotypes

What is sexual selection?

Ability to successfully obtain a mate

Be able to describe how each of the following lines of evidence support evolution. Be able to list specifically which each shows us. - the fossil record - biogeography - comparative anatomy and embryology - molecular biology - laboratory and field experiments

fossil record- physical evidence of organisms that lived in the past biogeography- patterns in the geographic distribution of organisms comparative anatomy and embryology- growth, development & body structures of major groups of organisms molecular biology- examination of life at the level of molecules laboratory and field experiments- enable us to watch evolution and progress

In natural selection, ____ determines which phenotypes are successful. A. chance B. the environment C. sample size D. genetic drift

B

Katie has 4 children with Nick. Nick has straight hair (recessive trait). three of their children have striaght hair and only one has curly hair. Whats Katie's genotype? A. CC B. Cc C. cc

B

Sam's genotype is Jj. He is A. Homozygous dominant B. Heterozygous C. Homozygous recessive

B

Katie is heterozygous (Ccbb) for curly hair and homozygous recessive for hair color since she is blonde. She marries nick with straight, brown hair (ccBb). How many of their kids are homozygous recessive for both traits? What about the pheotypic ratio? A. 0% B. 25% C. 50% D. 33%

B 4:4:4:4

What is the difference between homologous and analogous structures?

homologous- same structures, different function analogous structures- developed from different structures, same function

What is gene flow?

the movement of some individuals of a species from one population to another

a large herd of goats live in the mountains. One day, all but a few of them are killed by a sudden landslide. The small remaining population breeds forms a new herd, this is an example of? What if some goats crossed the mountains? How does this lead to evolution? What if some of these goats moved to a nice river valley and started a new population?

Bottleneck, Migration, geneflow, Founders

A male crab with 2 large front claws mates with a female with 2 small front claws and their offspring have one large and one small claw. What type of inheritance does claw length show? A. Mendelian inheritance B. incomplete dominance C. Codominance D. Polygenic inheritance

C

The latest news is taht a mom has given birth to 16 kids! Ouch! 9 have curly brown hair, 3 have curly blonde hair, 3 have straight brown hair, and 1 has straight blonde hair. What was the genotype of both parents? A. cant tell B. CCBB; ccbb C. CcBb; CcBb

C

What type of inheritance pattern does shoe size show? A. Codominance B. Divergent C. Polygenic - lots of variation D. pleiotropic

C. Polygenic - lots of variation

In order to determine Katie's genotype, what do we need to do? A. Punnett square B. Karyotype C. Test cross D. Pedigree

C. We don't know if you're Heterozygous or Homozygous recessive so you have to do a test cross to see what which one since the phenotype looks similar

What 2 major observations did Darwin make that shaped his theory of evolution?

1. traits exhibited by species or different species 2. similarity between fossils of species and extinct species in that same area

How many alleles of each gene do you have? Where did you get them?

2- your parents

Florists have been artificially selecting for roses with larger stems. As a result, the height of floral stalks for roses is shown above. This is an example of A. directional selection B. disruptive selection C. stabilizing selection

A

Some people considered the appendix a _______ because it has no known function today but it may have aided in the digestion of leaves in our caveman ancestors. A. Vestigial structure B. Homologous structure C. Analogous structure D. Mutation

A

The origin of all genetic variation is A. Mutation B. Genetic drift C. Gene flow D. Natural selection E. Evolution

A

codominance

A condition in which both alleles for a gene are fully expressed ex- red and white flower

Dihybrid cross Monohybrid cross Homozygous Heterozygous A. bb B. AABB x aabb C. Aa D. Aa x Aa

A. Homozygous B. Dihybrid cross C. Heterozygous D. Monohybrid Cross

What are Mendelian traits?

1. Controlled by one gene 2. Only 2 alleles = dominant and recessive 3. Law of segregation

What are 3 reasons why doesn't natural selection lead to perfect organisms?

1. Environments change quickly. 2. There may be multiple different alleles for a trait, each causing an individual to have the same fitness. 3. Variation is needed as the raw material of selection.

List and define the 4 agents that give rise to evolution.

1. Mutation 2. Genetic drift 3. Migration 4. Natural Selection

Distinguish the 3 conditions that must be satisfied in order for evolution to occur by natural selection

1. There must be variation for the particular trait within a population. 2. That variation must be inheritable. 3. Individuals with one version of the trait must produce more offspring than those with a different version of the trait.

if the allele frequency of "A" in the next population is .5 (and it was .55 in the past), has evolution occurred?

No, must go up/down by .1

allele frewuency

No. of alleles divided by total number of alleles

incomplete dominance

in which the heterozygote appears to be intermediate between the two homozygotes ex- pink flower

How is ancestry related to molecular biology?

it link all life forms.

Distinguish between the law of independent assortment and the law of segregation.

law of independent assortment- We inherit traits independently of each other law of segregation- you've got two copies of each gene but put only one copy in each sperm or egg.

Distinguish between linked genes and sex-linked genes.

linked genes: Genes on the same chromosome are sometimes inherited together. sex-linked genes: x chromosome more frequent in men because have only one copy of x chromosome

How does population size influence genetic drift?

much greater in small populations than in large populations

Variation in body coloration is what type of selection?

natural selection

Are organisms more closely related to different species in their area or to similar species found in a similar habitat but on another continent?

organisms more closely related to different species in their area

Who has a greater fitness, a world-class bodybuilder with a single child or an overweight, middle-aged accountant with four children?

overweight, middle-aged accountant with four children

genotype vs phenotype

phenotype -physical appearance (Brown hair) genotype- the genetic makeup (FF, Ff, ff)

Distinguish between polygenic traits and pleiotropy

polygenic traits- A trait that is influenced by many different genes (allow a wide range of physical traits ex- hair color, height, weight) pleiotropy- When one gene affects many traits