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Dihybrid crosses and gene linkage
Dihybrid crosses and gene linkage

... A new shuffling of the alleles has created a new combination which does not match either of the parents’ genotypes The term recombinant is used to describe both the new chromosome and the resulting organism. Recombinants form through the process of crossing over ...
Biology Chapter 11-5 - Wayne County Public Schools
Biology Chapter 11-5 - Wayne County Public Schools

...  Morgan and his friends found that the fruit fly had 4 linkage groups (genes that were inherited together).  The linkage groups assorted independently but all the genes were inherited together. ...
Asexual Reproduction in Eukaryotes: Mitosis
Asexual Reproduction in Eukaryotes: Mitosis

... Parthenogenesis = egg develops into an adult without fertilization. Some forms of parthenogenesis produce diploid egg by mitotic division; others do it by meiotic division followed by restoration of diploidy by various means. All usually called asexual. ...
The Human Chromosome
The Human Chromosome

... Most human traits arise from complex gene interactions, but many can be traced to autosomal dominant or autosomal recessive alleles that are inherited in simple patterns. ...
Document
Document

... • In this case, the frequency of recombination reaches is its maximum value of 50%, and the genes act as if found on separate chromosomes and are inherited independently. – In fact, several genes studies by Mendel are located on the same chromosome. • For example, seed color and flower color are far ...
Ch 10: Genetic Change and Variation
Ch 10: Genetic Change and Variation

...  Triploids are sterile because they cannot form complete homologous pairings. If, however, a hybrid has a chromosome number which is a multiple of the original chromosome number, a new fertile species is formed, e.g. wheat (n=42) is the cross between wild grass (n=14) and emmer wheat (n=28) ...
Exceptions to the Rules
Exceptions to the Rules

... Females need two copies of the gene to be colorblind. Males only get one copy of the x chromosome so if they get one copy of the gene they are colorblind. ...
044.1 Schleiermacher
044.1 Schleiermacher

... In neuroblastoma, the most frequent genetic alterations are unbalanced chromosome 17 translocations leading to gain of distal 17q, which is thought to play an important role in the oncogenesis of this tumor through a dosage effect of genes located on this chromosome. However, little is known about t ...
RF (mu) = NPD + ½(T)/total x 100
RF (mu) = NPD + ½(T)/total x 100

... Behavioral isolation: Species engage in distinct courtship and mating rituals (see Figure 1). Mechanical isolation: Interbreeding is prevented by structural or molecular blockage of the formation of the zygote. Mechanisms include the inability of the sperm to bind to the egg in animals, or the femal ...
Single Gene Inheritance
Single Gene Inheritance

... Lyon Hypothesis ...
handout on genetic nomenclature
handout on genetic nomenclature

... genes or alleles. Gene: single word, begins with upper case letter, at least two characters. An UPPER CASE gene name denotes the wild type form of a gene, or in the case of human, the sequence that is in the human genome database. Allele: Gene suffixed with dash and a numeral, indicating the allele. ...
Complementation
Complementation

... • Barr noticed that in the nucleus of females, but not males, a darkly staining body is visible. • Ohno hypothesized that this was an inactivated X chromosome in females so that there would only be 1 functional copy of genes, as in males. • Inactivated X is called a Barr body. • Individuals with inc ...
Genetics revision for learners
Genetics revision for learners

... Meiosis produces gametes with half the number of chromosomes. This means that pairs of alleles are separated at meiosis. During meiosis matching chromosomes cross over (swap sections of the chromosome) which adds variation. Independent assortment also increases variation as the chromosome pairs rand ...
Ch5-Genetics - Medical School Pathology
Ch5-Genetics - Medical School Pathology

... HIS SONS are OK, right? ALL his DAUGHTERS are CARRIERS The “Y” chromosome is NOT homologous to the “X”, i.e., the classic concept of ...
powerpoint human disorders - Social Circle City Schools
powerpoint human disorders - Social Circle City Schools

... 2. arrange by size 3. label # 1-23 pairs and each individual chromosome 4. match up with known karyotypes and ...
Human Genetic Disorders
Human Genetic Disorders

... • Sickle-cell disease (Sickle-cell Anemia) – Caused by abnormal hemoglobin (protein that carries oxygen) causing pain and weakness – The allele for it is co-dominant. – People with two sickle cell alleles have it – People with one sickle-cell allele produce both normal and abnormal hemoglobin but do ...
genetic disorders
genetic disorders

... tend to have speech and reading problems. At one time, it was suggested that these men were likely to be criminally aggressive, but it has since been shown that the incidence of such behavior among them may be no greater than among XY males. B. Klinefelter syndrome occurs in 1/ 1,500 births. These m ...
ethylene - IQMrevision
ethylene - IQMrevision

... In animals, female gametes are produced here ...
Human Genetics
Human Genetics

... the recessive form to show the trait. • Heterozygous individuals never show the trait, but do carry the recessive allele. • The trait may skip a generation in a family. • Males and females affected equally. • Examples: cystic fibrosis, tay-sachs disease, ...
Cell Mutations
Cell Mutations

... t hes unw ash otb utt heo ldm and idn otg ish at. ...
Biology Vocab Words
Biology Vocab Words

... between homologous chromosomes during meiosis one ...
iii hamarto-neoplastic syndromes
iii hamarto-neoplastic syndromes

... These two diseases are examples of the involvement of tumor suppressor genes; they are also of interest for various reasons; retinoblastoma mixes constitutional and acquired chromosome features, the gene Rb is autosomal recessive but the disease appears to be autosomal dominantly inherited, due to r ...
Genetics after Mendel
Genetics after Mendel

... Multifactorial – genes found at many loci Ex Height We have a range Humans and higher organisms ...
Document
Document

... Answer: These results can be explained by gene conversion. The gene conversion took place in a limited region of the chromosome (within the pdx-1 gene), but it did not affect the flanking genes (pyr-1 and col-4) located on either side of the pdx-1 gene. In the asci containing two pdx-1 alleles and s ...
PGS: 274 – 284
PGS: 274 – 284

... a. This is the result of a faulty gene (recessive) on the X chromosome for making a particular type of color absorbing protein in cones of the retina of the eye. b. The most common type is Red/Green Colorblindness. (Red and Green appear gray.) 2. Hemophilia (Means “love of bleeding”) a. These indivi ...
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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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