Combo with "Chapter 12" and 1 other – Flashcards

Unlock all answers in this set

Unlock answers
question
Through a microscope you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. The cell is most likely in
answer
a plant cell in the process of cytokinesis
question
Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to
answer
disruption of mitotic spindle formation
question
One difference between cancer cells and normal cells is that
answer
Cancer cell continue to divide even when they are tightly packed together
question
The decline of MPF activity at the end of mitosis is due to
answer
the degradation of cyclin
question
In the cells of some organisms, mitosis occurs without cytokinesiis. This result in
answer
cells with more than one nucleus.
question
Which of the following does not occur during mitosis?
answer
replication of DNA DOES occur in mitosis condensation of chromosomes, separation of sister chromatids, spindle formation, separation of the spindle poles
question
A particular cell has half as much DNA as some of the other cells in mitotically active tissue, the cell in question is most likely in
answer
G1
question
The drug cytochalasin B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by this drug?
answer
cleavage furrow formation and cytokinesis
question
A human cell containing 22 autosomes and a Y chromosome is
answer
a sperm
question
Which life cycle stage is found in plants but not animals?
answer
multicellular haploid
question
Homologous chromosomes move toward opposite poles of a dividing cell during
answer
meiosis I
question
Meiosis II is similar to mitosis in that
answer
sister chromatids separate during anaphase.
question
If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I, would be
answer
2x
question
If we continued to follow the cell lineage from question 5, then the DNA content of a single cell at metaphase of meiosis II would be
answer
x
question
How many different combinations of maternal and paternal chromosomes can be packaged in gametes made by an organism with a diploid number of 8 (2n 5 8)?
answer
16
question
Gene
answer
a. Has no effect on phenotype in a heterozygote
question
Allele
answer
b. A variant for a character
question
Character
answer
c. Having two identical alleles for a gene
question
Trait
answer
d. A cross between individuals heterozygous for a single character
question
Dominant Allele
answer
e. An alternative version of a gene
question
Recessive allele
answer
f. Having two different alleles for a gene
question
Genotype
answer
g. A heritable feature that varies among individuals
question
Phenotype
answer
h. An organism's appearance or observable traits
question
Homozygous
answer
i. A cross between an individual with an unknown genotype and a homozygous recessive individual
question
Heterozygous
answer
j. Determines phenotype in a heterozygote
question
Testcross
answer
k. The genetic makeup of an individual
question
Monohybrid cross
answer
l. A heritable unit that determines a character; can exist in different forms
question
Character Dominant Recessive Flower position Axial (A) Terminal (a) Stem length Tall (T) Dwarf (t) Seed shape Round (R) Wrinkled (r) If a plant that is heterozygous for all three characters is allowed to self-fertilize, what proportion of the offspring would you expect to be as follows? (Note: Use the rules of probability instead of a huge Punnett square.)
answer
1. homozygous for the three dominant traits 2. homozygous for the three recessive traits 3. heterozygous for all three characters 4. homozygous for axial and tall, heterozygous for seed shape
question
In sesame plants, the one-pod condition (P) is dominant to the three-pod condition (p), and normal leaf (L) is dominant to wrinkled leaf (l). Pod type and leaf type are inherited independently. Determine the genotypes for the two parents for all possible matings producing the following offspring:
answer
1. 318 one-pod, normal leaf and 98 one-pod, wrinkled leaf 2. 323 three-pod, normal leaf and 106 three-pod, wrinkled leaf 3. 401 one-pod, normal leaf 4. 150 one-pod, normal leaf, 147 one-pod, wrinkled leaf, 51 three-pod, normal leaf, and 48 three-pod, wrinkled leaf 5. 223 one-pod, normal leaf, 72 one-pod, wrinkled leaf, 76 three-pod, normal leaf, and 27 three-pod, wrinkled leaf
question
Phenylketonuria (PKU) is an inherited disease caused by a recessive allele. If a woman and her husband, who are both carriers, have three children, what is the probability of each of the following?
answer
1. All three children are of normal phenotype. 2. One or more of the three children have the disease. 3. All three children have the disease. 4. At least one child is phenotypically normal.
question
The genotype of F1 individuals in a tetrahybrid cross is AaBbCcDd. Assuming independent assortment of these four genes, what are the probabilities that F2 offspring will have the following genotypes?
answer
aabbccdd 1. AaBbCcDd 2. AABBCCDD 3. AaBBccDd 4. AaBBCCdd
question
1 individuals in a tetrahybrid cross is AaB-bCcDd. Assuming independent assortment of these four genes, what are the probabilities that F2 offspring will have the following genotypes?
answer
aabbccdd 1. AaBbCcDd 2. AABBCCDD 3. AaBBccDd 4. AaBBCCdd
question
What is the probability that each of the following pairs of parents will produce the indicated offspring? (Assume independent assortment of all gene pairs.)
answer
1. AABBCC 3 aabbcc → AaBbCc 2. AABbCc 3 AaBbCc → AAbbCC 3. AaBbCc 3 AaBbCc → AaBbCc 4. aaBbCC 3 AABbcc → AaBbCc
question
http://home.earthlink.net/~dayvdanls/CampSolCh14.htm
answer
chapter 15
question
A man with hemophilia (a recessive , sex-linked condition has a daughter of normal phenotype. She marries a man who is normal for the trait. What is the probability that a daughter of this mating will be a hemophiliac? A son? If the couple has four sons, what is the probability that all four will be born with hemophilia?
answer
Genotypes: A man with hemophilia is XhY where h = hemophilia gene and H = the normal gene. Any daughter with normal phenotype whose father has hemophilia will be a carrier. Her genotype must be: XhXH and not XHXH We can use a Punnett square to show the probability of a daughter or son having hemophilia. daughter x normal man XhXH x XHY A. If the daughter marries a normal male the probability of a daughter having hemophilia is zero. B. About 50% of male children would have hemophilia (Boxes 2 and 4 above) C. The probability that all 4 sons have inherited hemophilia would be: 1/2 x 1/2 x 1/2 x 1/2 or 1/16.
question
Pseudohypertrophic muscular dystrophy is an inherited disorder that causes gradual deterioration of the muscles. It is seen almost exclusively in boys born to apparently normal parents and usually results in death in the early teens. Is this disorder caused by a dominant or a recessive allele? Is its inheritance sex-linked or autosomal? How do you know? Explain why this disorder is almost never seen in girls.
answer
(a) Pseudohypertropic muscular dystrophy is a recessive allele because if it were dominant then the heterozygous female would die before she was sexually mature, and thus could not pass on the trait (b) Pseudohypertropic muscular dystrophy is a sex-linked trait because it only occurs in males. (c) It is never seen in girls because for a girl to be homozygous recessive (and express the trait) XmXm, her father would have to be hemizygous recessive XmY) and her mother would have to be heterozygous or homozygous recessive (XmXM or XmXm). It is impossible for a hemizygous recessive male or a homozygous recessive female to have children because they will die before being old enough to have children. The Punnett square above shows that in a cross between two apparently normal parents, but the mother is a carrier, three children will be normal but one, always a boy will inherit the disease.
question
A wild-type fruit fly (heterozygous for gray body color and normal wings was mated with a black fly with vestigial wings. The offspring had the following phenotypic distribution: wild type, 778; black-vestigial, 785; black-normal, 158; gray-vestigial, 162. What is the recombination frequency between these genes for body color and wing type.
answer
First count the total number of offspring 778+785+158+162 = 1883 In all dihybrid test crosses (a cross between a known heterozygote for two wild type traits and a homozygous recessive individual for both traits) the expected ratio of phenotypes if the genes are on separate chromosomes must be: wild type, 25%; black-vestigial, 25% black-normal, 25%; gray-vestigial, 25%. These results do not fit the experimental data above (778+785+158+162). In fact the black-normal (158) and gray-vestigial (162) offspring represent recombinant individuals. Calculation of recombination frequency: 778 - wild type 785 - black-vestigial 778/1883 = 41.3% 785/1883 = 41.7% 83% are non-recombinant 158 - black-normal 162 - gray-vestigial 158/1883 = 8.4% 162/1883 = 8.6% 17% are due to recombination Recombination frequency = 17% The generally accepted method of symbolizing the genotypes for a dihybrid cross of linked genes is as follows (pg. 264 - Campbell): b+ = wild-type (gray body) b = black body vg+ = normal wing shape vg = vestigial wings The testcross is symbolized as follows: If no cross over occurs then only two phenotypes should be seen. That is 50% of the offspring should be dominant for both traits ---- and the other 50% should be homozygous recessive ---- just as in the parents above. Cross over in the heterozygous parent results in 50% recombinants:
question
A space probe discovers a planet inhabited by creatures that reproduce with the same hereditary patterns seen in humans. Three phenotypic characters are height (T = tall, t = dwarf), head appendages (A = antennae, a = no antennae), and nose morphology (S = upturned snout, s = downturned snout). Since the creatures are not "intelligent," Earth scientists are able to do some controlled breeding experiments using various heterozygotes in testcrosses. For tall heterozygotes with antennae, the offspring are tall-antennae, 46; dwarf-antennae, 7; dwarf=no antennae, 42; tall-no antennae, 5. For heterozygous with antennae and an upturned snout, the offspring are antennae-upturned snout, 47; antennae-downturned snout, 2; no antennae-downturned snout, 48; no antennae-upturned snout, 3. Calculate the recombination frequencies for both experiments.
answer
Experiment 1 (Frequency/Distance between T and A). Determine the recombination frequency for the genes controlling Tallness and Antennae: 46 tall-antennae = 46% expected 42 dwarf-no antennae = 42% expected 7 dwarf-antennae = 7% recombinant 5 tall-no antennae = 5% recombinant Total = 100 Therefore this recombination frequency between genes T and A is 12% Experiment 2. (Frequency/Distance between A and S) Determine the recombination frequency for the genes controlling Antennae and Snout: 47 antennae-upturned snout = 47% expected 48 no antennae-downturned snout = 48% expected 2 antennae-downturned snout = 2% recombinant 3 no antennae-upturned snout = 3% recombinant Total = 100 Therefore this recombination frequency between genes A and S is 5%
question
What pattern of inheritance would lead a geneticist to suspect that an inherited disorder of cell metabolism is due to a defective mitochondrial gene?
answer
The disorder would always be inherited from the mother because the mother's mitochondrial gene is the only one that survives when the zygote is formed. The gamete from the mother contains all the information. The head of the father's sperm is the only part that survives during fertilization. The tail of the sperm containing the male's mitochondria (an their genes) is lost when the zygote begins development. Thus it is only from the mother that the disorder can be inherited.
question
2. Genomic imprinting
answer
A phenomenon in which expression of an allele in offspring depends on whether the allele is inherited from the male or female parent.
question
3. The difference between - complete dominance - incomplete dominance - codominance
answer
Complete dominance: Heterozygous phenotype same as that of homozygous dominate. Incomplete dominance: Heterozygous phenotype intermediate between the two homozygous phenotype. Codominance: Both phenotypes ezpressed in heterozygotes
question
4. Know about blood types and the genes involved
answer
page 273
question
5. What is trisomy?
answer
- An extra chromosome; down-syndrome (3 chromosome) - Klinefelter Syndrome -47 XXY - Turner Syndrome -45 X0 - Trisomy X -47 XXX
question
6. What does hemizygous mean?
answer
-used to describe the single copy of an x-linked gene in the male
question
7. Know Mendel's Laws of Segregation and Independent Assortment
answer
-The Law of Segregation is dependent on the separation of members of homologous pairs. -While the Law of Independent assortment is dependent on the random arrangement of homolohous chromosomes at the metaphase plate.
question
8. Why does a recessive phenotype reappear in the F2 generation when pea plants that are either homozygous dominant for a trait or homozygous recessive for a trait are crossed and then the F1 plants self-pollenated?
answer
-There is a 50% chance that i can reappear. 1:2:1 ratio
question
9. What is a tumor suppressor gene? In general, how do they function? What is apoptosis? Can you give examples of tumor suppressor genes?
answer
- Tumor suppressor gene is a gene that protects a cell from one step on the path to cancer. - The functions of tumor-suppressor proteins fall into several categories including the following: 1.Repression of genes that are essential for the continuing of the cell cycle. 2.Coupling the cell cycle to DNA damage. 3.If the damage cannot be repaired, the cell should initiate apoptosis (programmed cell death) to remove the threat it poses for the greater good of the organism. 4.Some proteins involved in cell adhesion prevent tumor cells from dispersing, block loss of contact inhibition, and inhibit metastasis. 5.DNA repair proteins are usually classified as tumor suppressors as well, as mutations in their genes increase the risk of cancer. - Apoptosis is the death of cells that occurs as a normal and controlled part of an organism's growth or development. - Example: p53 gene pRb, PTEN, pVHL, APC, CD95, ST5, YPEL3, ST7, and ST14.
question
What is independent assortment and when does it occur?
answer
The first meiotic division results in each pairing sorting its maternal and paternal homologs into daughter cells independently of every other pair. it occurs after metaphase 1.
question
What life cycle stage is found in plants but not animals?
answer
During phase 1 in animal cells; plant cells can not pinch
question
When do homologous chromosomes move toward the opposite poles in a dividing cell?
answer
Meiosis I in anaphase I because thats when they begin to head toward the spindle poles.
question
How is Meiosis II similar to mitosis?
answer
Second meiotic division is very similar to mitosis, except that meiosis II is not preceded by chromosomal replication. The chromosomes consisting of sister chromatids align at the equator. Then the sister chromatids separate, move to opposite poles and are surrounded by a re-formed nuclear membrane.
question
Know the phases of the cell cycle. When is DNA replicated? In what phase are mature cells? (i.e. nerve and muscle cells) When do the centrioles move apart? What is a centromere and how many are there per chromatid?
answer
DNA is replicated - during S (Synthesis) Mature cells - Go The centrioles move apart - during prophase 1 Centromere the point on a chromosome by which it is attached to a spindle fiber during cell division. 2 chromatid : 1 centromere
question
What is a cleavage furrow versus what is a cell plate?
answer
Cleavage furrow: on the outer surface indicates that two new cells are forming. Cell Plate: Plant cells form a cell plate that separates the two new cells.
question
Know the phases of mitosis, if you were shown an image with chromosomes, could you determine the mitotic phase?
answer
page 254
question
Be able to calculate probabilities... ex. When crossing an organism that is homozygous recessive for a single trait with a heterozygote, what is the chance of producing an offspring with the homozygous recessive phenotype?
answer
review lab worksheet/ 50%
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New