BIOL 1111 Lecture Notes - Lecture 13: Factor Ix, Enzyme, Organic Compound

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mauvescorpion525

23 Apr 2018

School

Northeastern University

Department

Biology

Course

BIOL 1111

Professor

Mary- Susan Potts- Santone

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Document Summary

78 genes have been found on y. Most code for traits important to both sexes. Females can be either heterozygous or homozygous. Show recessive phenotypes more often than females. White-eyed male x true breeding red-eyed female. F2 = 1:1 red and white males, no white-eyed females. Test cross f1 females to original male = 1:1:1:1 red and white males and females. One map unit = distance within which a crossover event is expected to occur in an average of 1% of gametes. Three-point cross - cross between three linked genes. P: homozygous recessive female x dominant male (wild type, +) Close together - do not assort independently - linked . Any crossing over on x chromosome will produce recombinant chromosomes. Aa x bb ab aabb. Both homologous end up in same daughter cell. Both sister chromatids end up in the same gamete. Eggs are as old as woman is. All produced and in prophase i by birth.

Related Questions

Answer the following Linked to sex genetics problems:

1.) In Drosophila the recessive mutation linked to the X chromosome, scalloped ( sd ), causes the edge of the wings to be irregular. Present the results (you must prepare the crossing scheme) phenotypic for F1 and F2 for a cross between:

A) female scallop and a normal male (regular edges)

B) A normal (homozygous) female and a scallop male .

C) Compare these results with those that would be obtained if scallop were an autosomal recessive mutation.

2.) In Drosophila the autosomal recessive ebony mutation (e) is located on chromosome 3 and produces a dark body in the fly that expresses it. What will be the phenotypic proportions for F1 and F2 that will be obtained from a cross between a scallop female and homozygous for a normal body, with an ebony male with normal wings? Solve by the bifurcated lines method.

3.) In Drosophila the recessive mutation linked to the vermilion X chromosome (v) produces bright red colored eyes in contrast to the wild phenotype that has brick red eyes. An autosomal recessive mutation, suppressor vermilion (su-v) causes homozygous or hemizygous males to females present vermilion red brick eyes. In the absence of the vermilion allele su-v has no effect on the phenotype of the eye. Determine the genotype and phenotype of F1 and F2 at a cross between a homozygous female for vermilion and su-v, with a vermilion male and wild homozygous for su-v (su-v + su-v + ) . Present the diagram of bifurcated lines for these crosses.

4.) At a crossroads with Drosophila involving recessive mutations white (linked to the X chromosome) and sepia (autosomal recessive) that produces dark eyes, predict the results of F1 and F2 when crossing pure parents with the following phenotypes.

A.) White females with sepia males.

B.) Sepia females with white males

5.) Two mothers have given birth to their children at the same time in an urban hospital with an excess of patients. The child of couple 1 has hemophilia, a condition caused by a recessive allele linked to the X chromosome. Neither parent has the condition. Couple 2 has a normal child even though the father is a hemophiliac. Several years later, couple 1 filed a lawsuit alleging that the babies were changed after birth and you are called to testify as a genetic counselor. What information would you give the jury in relation to the allegation of the couple 1?

___1. Nationally, the most common cause of Down Syndrome is
a. nondisjunction of Chromosome 21 during meiosis
b. translocation of Chromosome 21 onto another chromosome
c. inversion of a large section of Chromosome 21
d. deletion of the Down Syndrome gene
___2. In humans, sex is determined by
a. The presence or absence of the Y chromosome
b. The ratio of X chromosomes to sets of autosomes
c. The temperature during fetal development
d. Which parent is stronger at the time of conception
___3. A translocation is
a. a chromosomal abnormality in which a piece of one chromosome breaks off and attaches to a different chromosome
b. an abnormality in which the chromosomes are translocated out of the nucleus
c. a condition in which the chromosome has broken in two places and come back together with the middle segment backward
d. an abnormality in which there is an extra copy of one chromosome
___ 4. In snapdragons, a red-flowered plant crossed with a white-flowered plant produces all pink-flowered offspring. But crossing two pink-flowered plants produces red, pink, and white in a 1:2:1 ratio. This is a good example of
a. Incomplete dominance
b. Dominance of the red allele over the white allele
c. Lethal effects of the pink allele
d. Sex-linkage of the flower-color alleles
___ 5. If a person with type AB blood marries a person with Type O blood, what blood types are possible in their children? (Assume this trait is a single-gene trait, not complicated by interaction with other genes).
a. A, B, AB, or O
b. A or B only
c. AB or O only
d. AB only 2
___6. In what phase of meiosis are haploid nuclei first formed? a. Anaphase I b. Metaphase II c. Telophase II d. Metaphase I e. Telophase I
___7. What is the phenotype of a heterozygous tall pea plant? a. tall b. Tt c. TT d. tt e. dominant
___ 8. If genes A and B are far apart on a chromosome, and A and C are close together, which of the following observations is expected?
a. Crossing over will occur more often between A and C than between A and B
b. Crossing over will occur at equal frequencies between A and C, and between A and B
c. Crossing over will occur more often between A and B than between A and C
___9. Sometimes an organismâs genotype for one gene masks the effect of a different gene. This phenomenon is called
a. Dominance
b. Incomplete dominance
c. Co-dominance
d. Epistasis
e. Variable expressivity
___10. The dominant allele of a gene is
a. The one that is expressed most often in a population
b. The one that is expressed most often in any particular cross
c. The one that is expressed in an individual that has two different alleles
d. The one that is most healthy to have, that gives the greatest fitness
___11. In human cells, DNA replication occurs
a. In S phase of interphase
b. In G1 phase of interphase
c. In G2 phase of interphase
d. In prophase of mitosis
e. Whenever the cell needs to read the DNA to make proteins
___ 12. A process in which recipient cells take up genes from DNA molecules floating free in the surrounding medium is called
a. conjugation
b. specialized transduction
c. generalized transduction
d. transformation 3
___ 13. Most calico cats are female. However, a few rare males are observed. What is the genotype of a male calico cat?
a. X BX 0
b. X OY
c. X BY
d. X BYY
e. X BX OY
___ 14. A type of red-green color-blindness is a sex-linked (X-linked) recessive trait in humans. Can a woman have this type of color-blindness?
a. Yes, a woman could be color-blind if her mother and father were both heterozygous.
b. Yes, a woman could be color-blind but only if she has an abnormal number of sex chromosomes.
c. No, women can't show sex-linked traits because they lack a Y chromosome.
d. No, women can't show sex-linked traits because they have two X chromosomes.
e. Yes, a woman could be color-blind if her father was color-blind and her mother was a carrier (heterozygous).