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SEX DETERMINATION AND SEX CHROMOSOMES
SEX DETERMINATION AND SEX CHROMOSOMES

... (Figure 4.1b). In some insect species, the male has only one sex chromosome (the X) and is designated X0, whereas the female has a pair (two X’s). In other insect species, such as Drosophila melanogaster, the male is XY. For both types of insect species (i.e., X0 or XY males, and XX females), the ra ...
Name: _ Per: ______ Date: Chapter 14 Test Review Describe how
Name: _ Per: ______ Date: Chapter 14 Test Review Describe how

... develop into a male embryo because of the testosterone gene on the Y chromosome. Otherwise the embryo will develop as a female. 2. What are autosomes? Any of the chromosomes other than the sex chromosomes (X or Y chromosome, 23rd pair) 3. What are sex-linked genes? X-linked genes? Sex-linked genes a ...
SI Worksheet # 15 BY123 A mother is heterozygous for eye color
SI Worksheet # 15 BY123 A mother is heterozygous for eye color

... Females have two Xs and the dominant healthy X will have its genotype (normal) expressed. C. Why females are considered carriers? Why can’t males be carriers? If a female has one affected X and one normal X, she is a carrier and does not show the disorder. Males only have one X so they either have i ...
How to create a personalized syndrome description
How to create a personalized syndrome description

... 1. The annotated genes (Gene Dosage Map) includes information related to the gene dosage effects for each gene on chromosome 18 and are color codes as shown below. 2. The annotated phenotype regions (Phenotype Map) indicates the region of chromosome 18 linked to a specific phenotype for which a gene ...
JUNE EXAM QUESTIONS (LIVE) 03 JUNE 2015
JUNE EXAM QUESTIONS (LIVE) 03 JUNE 2015

... When the spindle fibres shorten/contract o All 4 chromosomes are pulled to one pole due to non-disjunction Resulting in two cells o one with 4 chromosomes, o and one with no chromosomes. The cell with 4 chromosomes undergoes meiosis 2 The 4 chromosomes line up at the equator in a single row When the ...
Chapter 14: Mendel and the Gene Idea
Chapter 14: Mendel and the Gene Idea

... Fig 15-10: Sex-linked disorders in humans: X Chromosome: Females: Inherit 2 X chromosomes, one from each parent - 2 alleles for all genes (Fig 15.9) Males: Inherit one X chromosome (from their mother), so only 1 allele for every gene, Technically, males are hemi-zygous - neither homozygous nor hete ...
Meiosis - Division of Physical & Biological Sciences
Meiosis - Division of Physical & Biological Sciences

... Metacentric- centromere in the middle Acrocentric- centromere towards the end Telocentric- centromere at the end ...
Nontraditional Inheritance
Nontraditional Inheritance

... Figure 2-1 Triplet repeat expansion in fragile X syndrome. The gel (A) shows Southern blot-based testing for several individuals including a normal male—lane 1, a normal female—lane 2, a female premutation carrier—lane 3, and an affected male—lane 4. DNA is double digested with EcoRI, a restriction ...
biology i honors capacity matrix unit vii: genetics
biology i honors capacity matrix unit vii: genetics

... two genes for each trait, one on the maternal chromosome and one on the paternal chromosome.  The two genes may be of the same form or they may be of different forms. o These forms produce the different characteristics of each trait. For example, a gene for plant height might occur in a tall form a ...
6SC06 Tutorial: Genetics – study of heredity
6SC06 Tutorial: Genetics – study of heredity

... states that genes are carried via chromosomes from the parents to their offspring. Each sex cell contains exactly half of each parent’s total number of chromosomes through a process known as meiosis. All organisms have a specific number of chromosomes that are different according to their particular ...
2/25/02 Lecture Highlights: Inheritance
2/25/02 Lecture Highlights: Inheritance

... • Through other crosses- determined yellow dominant to green and round peas dominant to wrinkled Mendel’s second experiment (dihybrid cross; 2 traits – pea color and pea shape) • F1 – all yellow, round (dominant traits) • F2 – not 3:1 ratio, but 9:3:3:1 ratio o He knew something other than segregati ...
Honors Biology Ch. 9 notes “Genetics” Mendel’s Laws
Honors Biology Ch. 9 notes “Genetics” Mendel’s Laws

... Found on the same chromosome. The closer they are on the same chromosome, the less likely they are to get separated by crossing over. So, they are usually inherited together. 9.18 How can crossing over frequency be used to make a gene map of a chromosome? ✍ The closer they are the less often they cr ...
Meiosis activity
Meiosis activity

... Today you will be working through the process of meiosis using paper chromosomes. It is important that you actually manipulate the chromosomes and draw the results. In thinking about how meiosis works, it is easiest to think about just a few chromosomes in a human cell, rather than all the chromosom ...
Genetic Disorders
Genetic Disorders

... Amniocentesis is a medical procedure used in prenatal diagnosis of chromosomal abnormalities and fetal infections, and also used for sex determination in which a small amount of amniotic fluid, which contains fetal tissues, is sampled from the amniotic sac surrounding a developing fetus, and the fet ...
Basic Principles of Heredity Notes AP Biology Mrs. Laux
Basic Principles of Heredity Notes AP Biology Mrs. Laux

... II. Gregor Mendel -first idea of modern genetics -Austrian (Czech Republic now) monk who discovered fundamental principles of heredity A. Background: (what we know now) 1. traits encoded in DNAchromosomes 2. geneseveral nucleotides that encode for a particular trait 3. allelevariation of gene -ge ...
Chapter 12: Inheritance Patterns and Human Genetics
Chapter 12: Inheritance Patterns and Human Genetics

... – Because males have only one X chromosome, a male who carries a recessive allele on the X chromosome will exhibit the sex-linked trait. ...
Unit_18_Mendelian_Genetics (2)
Unit_18_Mendelian_Genetics (2)

... It is not possible to tell the appearance if an individual is showing a dominant trait that is pure (BB) or hybrid (Bb). Therefore you must perform a test cross Test Cross – To determine the genotype of an organism showing a dominant phenotype, cross the organism with a recessive individual. If any ...
800X400 pixel file here
800X400 pixel file here

... observed chromosomes allows us to identify many characteristics. Further observation of banding on the chromosomes allows the determination of some gene aberrations (mistakes). Still, most single gene mistakes go unnoticed. (Special note: many single gene dysfunction can be determined by chemical an ...
Patterns of Inheretance
Patterns of Inheretance

... of many different colors • Some alleles are neither dominant nor recessive, and many traits are ...
Lecture 1: overview of C. elegans as an experimental organism
Lecture 1: overview of C. elegans as an experimental organism

... phenotype in F1 cross progeny and ratio of F2 animals that display mutant phenotype/wild type phenotype. How do you tell self from cross progeny especially if mutation is dominant? Use marker mutation to follow cross --Backcross: Cross mutant and wild type to removes unlinked mutations (50% per cros ...
Sordaria Meiosis and Crossing Over Lab Name Objective: To
Sordaria Meiosis and Crossing Over Lab Name Objective: To

... The spore color of the normal (wild type) Sordaria is black. This phenotype is due to the production of the pigment melanin and its deposition in the cell walls. Several different genes are involved in the control of the melanin biosynthetic pathway and each gene has two possible allelic forms. The ...
View/print full test page
View/print full test page

... o Approximately 10-11% of individuals with AS will not have an identifiable AS-causing genetic abnormality due to either incorrect clinical diagnosis or limitations of current methods of testing. ...
Chapter 2: Genes in pedigrees
Chapter 2: Genes in pedigrees

... primitive   plants,   diploid   and   haploid   cells   proliferate.    In  some  species  of  yeast,  only  haploid   cells   proliferate,   while   the   diploid   zygote   immediately   engages   in   meiosis   to   produce   new   ...
08_Human_chromosomes(plain)
08_Human_chromosomes(plain)

... autosomes. However note that two of the chromosomes, the X and the Y, do not look alike. These are sex chromosomes. In mammals, males have one of each while females have two X chromosomes. Autosomes are those chromosomes present in the same number in males and females while sex chromosomes are those ...
投影片 1
投影片 1

... Mutation • Mutation operators change some randomly selected bits of chromosomes. • If the chromosomes are binary strings, then ‘0’ are changed to ‘1’, and ‘1’ to ‘0’. It plays a secondary role after the crossover operator in genetic algorithms. • The changing bits means making an offspring genetica ...
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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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