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Sex and the genome
Sex and the genome

... mitotic. By contrast, Khil et al. examined intact testes, of which mitotic germ cells compose only a small percentage. Most germ cells in the testes are in various stages of meiosis and are subject to a process known as meiotic sex chromosome inactivation (MSCI), in which the sex chromosomes become ...
BIO 301
BIO 301

... In women, there are genes identified as been on the X chromosome which is referred to as X‐ linked and  which  are  referred  to  in  the  past  as  sex  linked  trait.  Since  there  is  a  true  pair  of  homologous  sex  chromosomes  in  human  females,  the  Mendel  law  of  dominant  and  reces ...
MCDB 1041 Quiz 1 Review Sheet An excellent way to review is to
MCDB 1041 Quiz 1 Review Sheet An excellent way to review is to

... a. Know human chromosome structure and number in humans (22 non-identical pairs of autosomes + either XX or XY = 46). b. Be able to describe Mitosis—how it works, what the result is, why cells do it. c. Know the function of the plasma membrane, the organelles and the nucleus, and why they are import ...
Biology-8
Biology-8

... Chromosome Maps  Recombination frequencies used to determine relative locations on a chromosome  Linkage map for genes a, b, and c: ...
Malattie XL, YL e Mitocondriali
Malattie XL, YL e Mitocondriali

... For some mutations the percentage level of mutant mtDNA tends to increase with transmission, and for others the level seems to decrease. The level of heteroplasmy is often markedly different between different tissues and Organs (some mutation decreases its level in blood throughout life; for other m ...
Study Questions – Chapter 1
Study Questions – Chapter 1

... 18. Using genetic markers, you find that the interval containing the gene is flanked by marker G and marker H. You identify the genes located between markers G and H and find a gene with a sequence variant that co-segregates with the disease. Meanwhile another group has tested a different gene and f ...
Mendelian Genetics
Mendelian Genetics

... • Genome- The complete set of all chromosomes • Genetics- The study of heredity • Gene – A piece of DNA that controls the synthesis of a specific protein • Trait – expression of a gene: i.e. a purple flower, determined by DNA • Dominant trait - expressed over recessive trait when both are present • ...
Sex determination and the Olympics
Sex determination and the Olympics

... Video about sex determination in humans and other organisms (looked at this in class): http://ed.ted.com/lessons/sex-determination-more-complicated-than-you-thought ...
CHROMOSOMAL BASIS OF INHERITANCE
CHROMOSOMAL BASIS OF INHERITANCE

... http://www.genomenewsnetwork.org/gnn_images/whats_a_genome/crossing_over.jpg ...
Sex Linked Traits - Thomas Hunt Morgan Fruit Fly Experiment
Sex Linked Traits - Thomas Hunt Morgan Fruit Fly Experiment

...  Human females inherit two copies of every gene on the X chromosome, whereas males inherit only one.  But for the hundreds of other genes on the X, are males at a disadvantage in the amount of gene product their cells produce? - The answer is no, because females have only a single active X chromos ...
6-6 Study Guide
6-6 Study Guide

... Refer to your cell sketch in the last box on the previous page. Also refer to Figure 2.3 if necessary. 1. In the first box below, show what your cell would look like at the end of meiosis I. Remember, the result will be two cells that have one duplicated chromosome from each homologous pair. 2. In t ...
Chromosomal Basis of Inheritance
Chromosomal Basis of Inheritance

... Why did this happen??? ...
GENETIC DISORDERS
GENETIC DISORDERS

... • There are 4 different ways chromosome structure can be damaged: ...
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... (i.e., 19/set). What would be the number of chromosomes in an allodiploid or allotetraploid produced from this cross? Would you expect the offspring to be sterile or fertile? Answer: An allodiploid would have 22 + 19 = 41 chromosomes. This individual would likely be sterile, because all the chromoso ...
Introducing the Chromosome Yr 12 Biology
Introducing the Chromosome Yr 12 Biology

... The Sutton-Boveri theory, otherwise known as the ‘chromosome theory of inheritance’, stated that chromosomes carried the units of inheritance and occurred in distinct pairs. The two scientists worked separately but came to the same conclusions. As there were more inheritable traits than there were c ...
S1.Describe how a gene family is produced. Discuss the common
S1.Describe how a gene family is produced. Discuss the common

... (i.e., 19/set). What would be the number of chromosomes in an allodiploid or allotetraploid produced from this cross? Would you expect the offspring to be sterile or fertile? Answer: An allodiploid would have 22 + 19 = 41 chromosomes. This individual would likely be sterile, because all the chromoso ...
CH 15 Chromosomal Basis of Inheritance Mendelian
CH 15 Chromosomal Basis of Inheritance Mendelian

... For a recessive X-linked trait to be expressed: A female needs two copies of the allele (homozygous) A male needs only one copy of the allele (hemizygous) ...
Chapter 15 practice Questions AP Biology
Chapter 15 practice Questions AP Biology

... A) The two genes likely are located on different chromosomes. B) All of the offspring have combinations of traits that match one of the two parents. C) The genes are located on sex chromosomes. D) Abnormal meiosis has occurred. E) Independent assortment is hindered. 2) A 0.1% frequency of recombinat ...
Mendel`s Laws and Genetics Quiz
Mendel`s Laws and Genetics Quiz

... Mendel’s Laws and Genetics Quiz 1. The two versions of a gene for a characteristic are called a) genotypes. b) phenotypes. c) alleles. d) chromosomes. ...
Chromosome Mutation - Hicksville Public Schools
Chromosome Mutation - Hicksville Public Schools

... 17. Sickle Cell Anemia - blood disorder causing sickling of the red blood cells 18. Tay-Sachs Disease - damage of the nerve cells in brain and spinal cord 19. Turner Syndrome - lack of either one whole or a part of an X chromosome 20. Wilson’s Disease - body’s inability to get rid of excess copper i ...
Notes
Notes

... - affects phenotypic characteristics Ex: sickle-cell anemia (single recessive allele on both homologues) causes formation of abnormal hemoglobin which in turn causes: breakdown of red blood cells, clumping of cells & clogging of small blood vessels, accumulation of sickle cells in spleen ...
Chromosomes & Inheritance
Chromosomes & Inheritance

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powerpoint
powerpoint

... abnormality including the PWS/AS region ...
Non-Disjunction & Aneuploidy
Non-Disjunction & Aneuploidy

...  Most common cause of mental retardation ...
Biology HW Chapter 14 (Due Apr 29, Test Apr 30)
Biology HW Chapter 14 (Due Apr 29, Test Apr 30)

... ____ 43. To make a karyotype, biologists take pictures of cells during mitosis, when they are condensed and easier to view. _________________________ ____ 44. A recessive X-linked trait would be more common in males than in females. _________________________ ____ 45. Two parents who have Huntington ...
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Skewed X-inactivation

Skewed X chromosome inactivation occurs when the inactivation of one X chromosome is favored over the other, leading to an uneven number of cells with each chromosome inactivated. It is usually defined as one allele being found on the active X chromosome in over 75% of cells, and extreme skewing is when over 90% of cells have inactivated the same X chromosome. It can be caused by primary nonrandom inactivation, either by chance due to a small cell pool or directed by genes, or caused by secondary nonrandom inactivation, which occurs by selection. Most females will have some levels of skewing. It is relatively common in adult females; around 35% of women have skewed ratio over 70:30, and 7% of women have an extreme skewed ratio of over 90:10. This is of medical significance due to the potential for the expression of disease genes present on the X chromosome that are normally not expressed due to random X inactivation. X chromosome inactivation occurs in females to provide dosage compensation between the sexes. If females kept both X chromosomes active they would have twice the number of active X genes than males, who only have one copy of the X chromosome. At approximately the time of implantation (see Implantation (human embryo), one of the two X chromosomes is randomly selected for inactivation. The cell undergoes transcriptional and epigenetic changes to ensure this inactivation is permanent. All progeny from these initial cells will maintain the inactivation of the same chromosome, resulting in a mosaic pattern of cells in females.
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