AP BIO UNIT 5 SIMPSON
recombination frequency
# Recombinants / # Total offspring x 100 under 50% is linked
human reproduction steps
1. male and female undergo meiosis 2. sperm(n) and ova/egg(n) are fertilized 3. then you have a zygote(2n) 4. then the zygote undergoes mitosis 5. then embryo development 6. then mitosis 7. then diploid adult
translocation
2 chromosomes that aren't homologous, part of one is transferred to the other
Based on Table 5-5, the mean map distance between gene R and gene L is closest to which of the following? A) 0.28 map units B) 28 map units C) 0.14 map units D) 14 map units
28 map units
product of meiosis
4 haploid cells that are not genetically identical
Based on Figure 5-3, which of the following questions could best be addressed? A) Does synapsis of homologous chromosomes in the parent cell contribute to an increase in genetic diversity in the daughter cells? B) Do sister chromatids separate and form diploid daughter cells? C) Do chromatids from nonhomologous chromosomes rearrange to produce identical daughter cells? D) Does synapsis of homologous chromosomes produce daughter cells that are identical to the parent cell?
A) Does synapsis of homologous chromosomes in the parent cell contribute to an increase in genetic diversity in the daughter cells?
For this condition, which of the following modes of inheritance is most consistent with the observations based on Figure 5-5? A) autosomal dominant B) Autosomal Recessive C) X-linked dominant D) X-linked recessive
A) autosomal dominant
polygenic inheritance
An additive effect of two or more genes on a single phenotypic character.
Heterozygous
An organism that has two different alleles for a trait
Phenotype
An organism's physical appearance, or visible traits.
(d) Predict the effect of increasing global temperatures on the continued presence of the W chromosome in this species of lizard. Scientists claim that, in this species, the Wchromosome is unimportant in sex determination. Instead, proteins that are encoded by a gene or genes on the Z chromosome, and that are maximally expressed only at certain temperatures, are responsible for determining whether embryos will develop as females or males. Use the data to support this claim.
At temperatures over 33C, there is a sharp shift towards female sex of XX individuals rather than males. The W chromosome determines a female, but is not required to do so. Increasing temperatures can also produce females. Therefore, the presence of the W chromosome will likely reduce or even disappear entirely, and the species could just rely on temperature to determine sex.This is supported by the data showing that the presence of the W chromosome is not at all required to develop into a female. If you look at the ZZ x ZZ crosses, you can get all males or or females or a mix completely dependent on temperature, without a W chromosome in sight.
The students plan to use a significance level of p=0.01. Based on Table 5-4, which of the following is the most appropriate critical value for the students to use in their chi-square goodness-of-fit test? A) 7.82 B) 11.34 C) 13.28 D) 326.7
B) 11.34
Based on Table 5-8, the mean number of fruit flies per student that are homozygous recessive for both genes is closest to which of the following? A) 89.75 B) 29.0 C) 22.75 D) 18.5
B) 29.0
How many degrees of freedom should be used when looking up the critical value for a chi-square analysis of the ratios of phenotypes observed among the F2 offspring versus the expected phenotypic ratio assuming independent assortment based on Table 5-1? A) 2 B) 3 C) 4 D) 5
B) 3
Based on Figure 5-8, If the woman and a man with normal clotting function have children, what is the probability of their children exhibiting hemophilia A? A) 50 percent for daughters, 0 percent for sons B) 50 percent for sons, 0 percent for daughters C) 50 percent for all children D) 0 percent for all children
B) 50 percent for sons, 0 percent for daughters
Which of the following is closest to the calculated chi-square (χ2) value for the data presented in Table 5-2? A) 8,35 B) 72.01 C) 98.00 D) 2,546.00
B) 72.01
When a mustard plant seedling is transferred to an environment with higher levels of carbon dioxide, the new leaves have a lower stomata-to-surface-area ratio than do the seedling's original leaves. Which of the following best explains how the leaves from the same plant can have different stomatal densities when exposed to an elevated carbon dioxide level? A) Increased photosynthesis leads to larger leaves that need more stomata for photosynthesis, leading to an increase in stomatal density. B)
B) Leaf growth is promoted through increased photosynthesis, but the genetically regulated rate of stomatal production is not altered, leading to a decrease in stomatal density.
Glycolysis is a metabolic pathway that converts glucose into pyruvate and is observed in each of the three domains. The hexokinase family of enzymes is required during glycolysis to phosphorylate six-carbon sugars. Researchers designed a general hexokinase inhibitor that is effective in the neurons of rats. Which of the following best predicts the effect of adding this inhibitor to a culture of plant cells? A) Plant cells will be unaffected by the inhibitor as they do not perform glycolysis. B)
B) Plant cells will be unable to perform glycolysis due to the inhibitor and will die.
Which of the follow indicates the mean number per cross of F2 plants producing medium-red grain and correctly explains the distribution of the phenotypes based on Table 5-7? A) The mean number of medium-red phenotypes per cross is 20.8. The distribution of phenotypes suggests that grain color is under environmental control. B) The mean number of medium-red phenotypes per cross is 20.8. The distribution of phenotypes suggests that multiple genes are involved in grain color determination. C) The m
B) The mean number of medium-red phenotypes per cross is 20.8. The distribution of phenotypes suggests that multiple genes are involved in grain color determination.
Based on Table 5-9, which of the following is most likely the immediate cause of the first appearance of Huntington's disease in a person? A) A point mutation occurs in the HTT gene B) The first appearance of CAG repeat occurs in the HTT gene. C) An allele with more than 39 CAG repeats was inherited by the affected person. D) The person inherited two alleles that each contained 20 CAG repeats.
C) An allele with more than 39 CAG repeats was inherited by the affected person.
The tadpoles of Mexican spadefoot toads are known to exhibit phenotypic plasticity depending on food availability. Tadpole mouthparts can vary significantly, prompting researchers to categorize them as either omnivore-morph or carnivore-morph. Carnivore-morph tadpoles are larger and have mouthparts that are better suited for predation. Remarkably, carnivore-morph tadpoles can change into omnivore-morph tadpoles when the food supply changes. Which of the following best describes an advantage of
C) It gives the tadpoles increased versatility with respect to diet.
Which of the following best explains how the sweet pea plants in the parental generation produce F1 offspring with 14 chromosomes based on Figure 5-1 and Table 5-1? A) Meiosis II and IIII lead to the formation of cells with 14 chromosomes. When two cells combine during fertilization, extra chromosomes are randomly broken down, leading to offspring with 14 chromosomes. B) Meiosis I and II lead to the formation of cells with 14 chromosomes. When two cells combine during fertilization, extra chromo
C) Meiosis I and II lead to the formation of cells with 7 chromosomes. During meiosis I, homologous chromosomes separate. During meiosis II, sister chromatids separate. Two cells combine during fertilization to produce offspring with 14 chromosomes.
For sexually reproducing diploid parent cells, which of the following statements best explains the production of haploid cells that occurs in meiosis but not in mitosis? A) Separation of chromatids occurs once, and there is one round of cell division in meiosis. B) Separation of chromatids occurs twice, and there are two rounds of cell division in mitosis. C) Separation of chromatids occurs once, and there are two rounds of cell division in meiosis. D) Separation of chromatids occurs twice, and
C) Separation of chromatids occurs once, and there are two rounds of cell division in meiosis.
Which of the following best predicts the effect of the chromosomal segregation error shown in Figure 5-7? A) All of the resulting gametes will have an extra chromosome. B) All of the resulting gametes will be missing a chromosome. C) Half of the resulting gametes will have an extra chromosome and the other half will be missing a chromosome. D) Half of the resulting gametes will have the correct number of chromosomes, and the other half will have an incorrect number of chromosomes.
D) Half of the resulting gametes will have the correct number of chromosomes, and the other half will have an incorrect number of chromosomes.
Which of the following best explains a distinction between metaphase I and metaphase II? (You can use Figure 5-2 as a reference here) A) The nuclear membrane breaks down during metaphase I but not during metaphase II. B) Chromosomes align at the equator of the cell during metaphase II but not during metaphase I. C) The meiotic spindle is needed during metaphase I but not during metaphase II. D) Homologous pairs of chromosomes are aligned during metaphase I, but individual chromosomes are aligned
D) Homologous pairs of chromosomes are aligned during metaphase II, but individual chromosomes are aligned during metaphase IIII.
A compound that prevents the separation of the homologous chromosomes in anaphase I is being studied. Which of the following questions can be best answered during this study based on Figure 5-3? A) Will the cells produced at the end of meiosis still be genetically identical to each other in the presence of this compound? B) Will the long-term development of the individual be affected by this meiotic error? C) When do the centrosomes start to move apart during meiosis I as compared to meiosis II?
D) Is there a pattern to the movement of homologous chromosomes in the presence of this compound?
Using a significance level of p=0.05, which of the following statements best completes a chi-square goodness-of-fit test for a model of independent assortment based on Table 5-3? A) The calculated chi-square value is 0.66, and the critical value is 0.05. The null hypothesis can be rejected. B) The calculated chi-square value is 0.66, and the critical value is 3.84. The null hypothesis cannot be rejected. C) The calculated chi-square value is 3.91, and the critical value is 5.99. The null hypothe
D) The calculated chi-square value is 3.91, and the critical value is 7.82. The null hypothesis cannot be rejected.
The researchers calculated a chi-square value of 29.25. If there are three degrees of freedom and the significance level is p=0.05, which of the following statements best completes the chi-square test based on Table 5-6? A) The critical value is 0.05, and the null hypothesis cannot be rejected because the calculated chi-square value is greater than the critical value. B) The critical value is 0.05, and the null hypothesis can be rejected because the calculated chi-square value is greater than th
D) The critical value is 7.82, and the null hypothesis can be rejected because the calculated chi-square value is greater than the critical value.
Himalayan rabbits are a breed of rabbits with highly variable fur color. If genetically similar rabbits are raised in environments that have different temperature conditions, the rabbits can have different color patterns. Which of the following statements best explains how the fur color can be different in Himalayan rabbits raised under different temperature conditions? A) The genotype does not contribute to coat color in Himalayan rabbits. B) The phenotype determines the genotype of coat color
D) The environment determines how the genotype is expressed.
Which of the following questions would be most useful to researchers trying to determine the role of meiosis in the F2 phenotypic frequencies based on Figure 5-1 and Table 5-1? A) What is the molecular mechanism underlying the dominance of erect petals and long pollen? B) Which phenotypes give pea plants the highest level of fitness: erect or hooded petals and long or round pollen? C) How do the phases of meiosis differ between sweet pea plants and other organisms? D) What is the recombination f
D) What is the recombination frequency between the genes for petal shape and pollen shape?
Alleles
Different forms of a gene
(b) Using the template, construct an appropriately labeled graph, including error bars, to represent the data in Table 1. Based on the data, compare the ZZm×ZWf crosses and the ZZm×ZZf crosses to determine whether there is a significant difference between the two crosses in the fraction of female progeny produced at 24°C, 32°C, and 36°C.
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linked genes
Genes located on the same chromosome that tend to be inherited together in genetic crosses.
Homozygous
Having two identical alleles for a particular gene
(a) If a particular gene is located on the Z chromosome of this lizard species, describe why a lizard with a ZW genotype has a greater probability of expressing the recessive phenotype for the trait than a lizard with the ZZ genotype does.
If there is no dominant allele for a trait present on a homologous chromosome to mask the recessive allele, the recessive phenotype will be expressed. In this case, the gene is located on the Z chromosome. In an individual with a ZW genotype (female) there is no homologous Z partner, meaning whatever allele is present on the solitary Z chromosome will be expressed.
(a) Describe the process in meiosis that ensures that both maternal and paternal chromosomes are passed on to each spermatozoon.
Meiosis is a type of cell division in which the ploidy of the organism reduces to half in the daughter cells. Meiosis produces 4 daughter cells from 1 parent cell with a different combination of the genetic material but haploid chromosomes. The meiosis process takes place in two stages in which during the first stage, the homologous chromosomes separate reducing the chromosome number to half that is from diploid chromosomes of parents to haploid in daughter. Since the process of meiosis form haploid gametes in both male and female therefore after fertilization restores the diploid chromosomes of the parent cell and form a diploid structure.
(d) A student claims that if the animal producing the spermatozoa has a mutation in a mitochondrial gene, the probability that any offspring will inherit the mutation is zero. Provide evidence to support this claim.
Mitochondrial DNA is inherited from the maternal side. The mitochondria from the sperm cell including their DNA are degrade after fertilization.
(c) In some instances, meiosis of a primary spermatocyte with six chromosomes results in two spermatozoa that contain four chromosomes and two spermatozoa that contain two chromosomes. Predict the most likely cause.
Nondisjunction, it occurs when chromosomes do not align and separate properly prior to the formation of daughter cells, during meiosis I or II. This means that some gametes are missing some chromosomes, and other gametes have extra chromosomes. This is usually lethal, however, some genetic disorders in humans are caused by chromosome nondisjunction. For example, Down's syndrome is caused when the original gamete has an extra copy of chromosome 21, meaning the individual contains 3 copies of chromosome 21.
describe meiosis in plants and animals, giving specific attention to the following: a. the stages of meiosis b. the function of meiotic daughter cells and the organs where meiosis takes place c. the contributions to genetic variation
Prophase 1-nuclear membrane breaks down, chromatin condenses into chromosomes, MTOC's go to opposite poles, spindles develop Synapsis-homologous chromosomes pair, crossing over between non-sister chromatids=genetic material exchange, spindles connect to centromere and pull to middle metaphase 1-chromosomes aligned anaphase 1-each member of the homologous pair of chromosomes pulled to opposite poles telophase 1-nuclear membrane appears cytokinesis and short interphase 1 may occur prophase 2-same as prophase 1, but no synapsis metaphase 2- chromosomes spread in the middle, no pairing anaphase 2-chromosomes separated into 2 chromatids/chromosomes and pulled by spindles to opposite poles telophase 2-meiosis concluded, cytokinesis separates nuclear into 4 haploid cells reduction division in sexual reproduction. Daughter cells haploid. Gametes--sex cells crossing over, metaphase 1 when homologous pairs randomly align, zygote is combination of randomly selected egg and sperm
Based on the data in Figure 5-4, which of the following is the best prediction of the mode of inheritance of red eyes in Japanese koi? A) The allele for red eyes is inherited in an autosomal dominant pattern. B) The allele for red eyes is inherited in an autosomal recessive pattern. C) The allele for red eyes is inherited in an X-linked recessive pattern. D) The allele for red eyes is inherited in an X-linked dominant pattern.
The allele for red eyes is inherited in an autosomal dominant pattern.
genetic recombination
The regrouping of genes in an offspring that results in a genetic makeup that is different from that of the parents.
(b) Explain why the genetic content of individual chromosomes in a spermatozoon most likely differs from the genetic content of individual chromosomes in a primary spermatocyte.
The spermatozoon is a mature cell with having haploid (N) number of chromosome while primary spermatocytes are immature cell with having diploid (2N) number of chromosomes.Spermatozoon - It is the term used to describe the motile mature sex cell of the male organism. These cells have a haploid (N) number of chromosomes. Spermatozoon has one or more swimming flagella with a head-on anterior side. This cell is ready to fertilize with the female egg cell to produce a zygote.Primary spermatocytes - This is a diploid cell having a 2N number of chromosomes. Primary spermatocyte refers to the cell before the process of Meiosis I. After Meiosis I secondary spermatocytes are produced which have half the number of chromosomes.
sex-linked traits
Traits controlled by genes located on sex chromosomes.
(c) For each cross, describe whether genetics or temperature determines the sex of progeny produced from eggs incubated at 35°C. For each cross, describe whether genetics or temperature determines the sex of progeny produced from eggs incubated at 24°C.
ZW females X ZZ males at 24°CHalf of the progeny are female. This is likely determined by genetics, as there is a 50/50 chance that the offspring inherit Z or W from mother, and always Z from fatherZZ females X ZZ males at 24°CNone of the progeny are female. This is determined by genetics and temperature, as there are no W chromosomes to pass on to the offspring, meaning all offspring will always be ZZ. At this temperature, that means no ZZ females are produced.ZW females X ZZ males at 35°CAlmost all of the progeny are female. This is likely temperature dependent, because there is equal possibility genetically that offspring could be male or female (inherit W or Z). However, the proportions are different between 24 and 36C, suggesting higher temperatures influence the sex determination. At higher temperatures, ZW and ZZ individuals develop into femalesZZ females X ZZ males at 35°CAlmost all of the progeny are female. This is likely temperature dependent, because there is equal poss
zygote
a fertilized egg
independent assortment
after homologous pairs of chromosomes line up at metaphase 1, it's a matter of chance
when mutations happen in gametes they ________ passed to offspring
are
when mutations happen in somatic cells they _________ passed to offspring
aren't
somatic cells
body cells
codominance
both alleles are completely expressed at the same time like spots or stripes
chromosomal mutations
changes lots of genes, change in structure, gain or loss
inversion
chromosome segment breaks off, a piece of a chromosome is lost
chromosomes
condensed chromatin, humans have 46 chromosomes
genetic variation is a product of meiosis. In two or three sentences, describe how genetic variation is created by meiosis
crossing over during the condensation phase of meiosis (prophase 1) produces chromosomes with genetic material from both parents. Also, the joining of gametes during sexual reproduction creates genomes in offspring that are unique .
meiosis creates genetic variability by
crossing over, independent assortment, random fertilization
types of chromosomal mutations
deletion, inversion, translocation, nondisjunction, duplication
many of the activities that occur during mitosis and meiosis are similar. In two or three sentences, describe one stage of meiosis that is distinctively different from mitosis.
during chromosome alignment in meiosis(metaphase 1), homologous chromosomes pair on the equatorial plate and subsequently homologues separate to opposite poles. In contrast, during the same phase of mitosis, the chromosomes all lineup and chromatids separate to opposite poles
crossing over
exchange of genetic material that occurs in the chiasma and results in recombinant chromatids and increases genetic variability of the products
chromosome are made up of
genes
gentoype
genetic makeup of an organism
Mitochondrial DNA (mtDNA)
genetic material in the mitochondria of the cytoplasm of a cell; only inherited from the mother
nondisjunction
homologous pairs fail to separate at anaphase 1-sister chromatids fail to separate or homologous chromosomes may not remain together
Barr bodies
inactivated X chromosomes found only in females
further apart genes are
more likely that they will cross over
epistasis
occurs when a gene at one locus alters or influences the expression of a gene at a second loci
asexual reproduction
offspring are clones, genetically identical to parents, can occur without sex
sexual reproduction
requires gametes, genetic variability
gamete
sex cells
incomplete dominance
some alleles don't completely dominate others, partially show by blending together how they are expressed
homologous chromosomes pair by what in meiosis 1
synapsis
phenotypic plasticity
the ability of an organism to change its phenotype in response to changes in the environment.
complete dominance
the dominant all shows up in the offspring and the recessive allele gets covered up and doesn't show
multiple alleles
three or more forms of a gene that code for a single trait