BIOL239 Chapter Notes - Chapter 13: Nondisjunction, Down Syndrome, Edwards Syndrome

160 views12 pages

scarletbee935

6 Mar 2017

School

University of Waterloo

Department

Biology

Course

BIOL239

Professor

Christine Dupont

For unlimited access to Textbook Notes, a Class+ subscription is required.

Document Summary

Xb = orange: during embryo formation, some xbxb will get b turned off, some b. Makes the remaining expression viable: xo: turner syndrome: abnormal, infertile female. But the telomere/centromere genes remaining are expressed so lead to double expression of some female genes, which appears in the phenotype by looking feminized. With an x donated into fertilization in females: females can receive y or x from male while males can only receive an x, describe how non- disjunction for sex chromosomes can lead to different aneuploid offspring. With a y donated into fertilization: females can receive y or. X from male, while males can only receive an x mi is homolog, mii is sister chromatid. Klinefelter, lethal: remember empty means everything but sex chromosomes are doing it fine. Can klinefelter"s be due to nondisjunction during meiosis in the male: no, yes, 1st division only, yes, 1st or second division, yes, 2nd division only.

Related Questions

1. Chromosome morphology types include

: A. telocentric, in which the telomere is near one end of thechromosome. B. metacentric, in which the centromere is near one endof the chromosome. C. paracentric, in which the telomere issomewhat off center. D. telocentric, in which the centromere isnear one end of the chromosome. E. None of the above.

2. A karyotype is

: A. the set of chromosomes of an individual. B. 23 pairs. C. 46chromosomes. D. All of the above. E. None of the above.

3. Mutations that affect chromosome structure include all of thefollowing EXCEPT

: A. duplication. B. deletion. C. inversion. D. translation. E.Actually, all of these are mutations that affect chromosomestructure.

4.Duplications can have all of the following effects EXCEPT

: A. providing material for genetic variation and innovation. B.looping out of chromosomes during meiosis. C. novel phenotypes dueto dosage variation. D. suppression of crossing over. E. Actually,all of these can be effects of duplications.

5. Inversions:

A. include paracentric inversions, which include the centromere.B. include pericentric inversions, which do not include thecentromere. C. suppress crossing over in the inverted areas. D.usually lead to dicentric bridges. E. All of the above.

6. Translocations:

A. include reciprocal translocations, in which exchange ofchromosomal parts occurs. B. include nonreciprocal translocations,in which one chromosome donates material to another. C. suppresscrossing over in the case of reciprocal exchanges. D. can involveloss of material, as in Robertsonian translocations. E. All of theabove.

7. Unequal crossing over often leads to

: A. duplications. B. deletions. C. translocations. D. A and B.E. All of the above.

8. Aneuploidy includes all of the following EXCEPT:

A. nullisomy. B. monosomy. C. trisomy. D. tetrasomy. E.Actually, all of these are forms of anueploidy.

9. While anueploidy is a change in the number of chromosomes,polyploidy is:

A. a change in the number of sets of chromosomes. B. a change inthe structure of the chromosomes. C. an increase in the rate ofrecombination. D. an increase in the rate of mutation. E. None ofthe above.

10. Polyploidy includes:

A. autopolyploidy, which doubles the chromosome set as a resultof mitotic failure. B. autopolyploidy, which doubles the chromosomeset as a result of meiotic failure. C. allopolyploidy, whichdoubles the chromosome set as a result of meiotic failure. D. A andB. E. All of the above.

silverwolf483

___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).

M2A1 Worksheet: Mitosis and Meiosis

A dog is a diploid organisms and has 39 pairs of chromosomes (2n = 78), where n = 39 chromosomes from each parent. Use this example to answer the following question regarding chromosomal number.

INTERPHASE

How many chromosomes are present in the somatic cell?

What do they look like?

What are they âdoingâ in G1 of this phase?

What is happening in the S phase?

What is happening in the G2 phase?

What follows G2 phase in a somatic cell?

What follows G2 phase in a gamete cell?

MITOSIS

Number of chromosomes in the parent cell.

Number of chromatids in the parent cell.

Number of chromosomes in the daughter cell.

Number of chromatids in the daughter cell.

How many daughter cells are produced?

Are the daughter cells haploid or diploid?

How many cell divisions take place?

In what type of cell does this division occur?

Meiosis 1:

Number of chromosomes in the parent cell.

Number of chromatids in the parent cell.

Number of chromosomes in each Meiosis I daughter cell.

Number of chromatids in each Meiosis I daughter cell.

Are the daughter cells haploid or diploid at the end of Meiosis 1?

Meiosis II:

Number of chromosomes in the âparentâ cell (which is a daughter cell from Meiosis I).

Number of chromatids in the âparentâ cell.

Number of chromosomes in each Meiosis II daughter cell.

Number of chromatids in each Meiosis II daughter cell.

Are the daughter cells haploid or diploid at the end of Meiosis II?

Which phase or phases of Meiosis account for the genetic variability among the daughter cells? Howâ¦ what happens in this phase to create the diversity?

Comparing Mitosis and Meiosisâ¦..

How many daughter cells result from Mitosis? Are they diploid or haploid?

How many daughter cells result from Meiosis? Are they diploid or Haploid?

Cell structures and function: Match each organelle to its function:

Organelle Function

Lysosome 1. Lipid synthesis

Rough ER 2. Houses DNA

Nucleus 3. Energy extraction

Smooth ER 4. Dismantles debris

Golgi apparatus 5. detoxification

Mitochondria 6. Protein synthesis

Peroxisome 7. Processes secretions

What is the function of checkpoint proteins in the cell cycle?

How can all of a personâs cells contain exactly the same genetic material, yet specialize as bone cells, nerve cells, muscle cells and connective tissues?

What are the 3 primary germ layers?

Briefly, in one or two sentences, distinguish between

a bacterial cell and a eukaryotic cell

interphase and mitosis

mitosis and apoptosis

an autosome and a sex chromosome

homologous pair of chromosomes and a sister chromatid

centromere and centriole

chromosome and chromatid

monozygotic and dizygotic twins

allele and gene

BIOL239 Chapter Notes - Chapter 13: Nondisjunction, Down Syndrome, Edwards Syndrome

Document Summary

Get access

Related Documents

BIOL239 Lecture Notes - Xyy Syndrome, Zygosity, Barr Body

BIOL239 Lecture Notes - Lecture 13: Parthenogenesis, Mendelian Inheritance, Mitosis

BIOL239 Study Guide - Final Guide: Wysiwyg, Angiogenesis, Lac Operon

Related Questions