Bio Study

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pedigree

pedigree

chart showing passing down of genetic traits through generations.

Autosomal Linked Genes

genes located not on chromosomes; not linked to any sort of X or Y, gender has no factor in inheriting.

Carriers

Peoples who appear with the dominant phenotype but still can pass down the recessive allele.

Cystic Fibrosis

Example of recessive genetic disease that is commonly carried in 1/31 Americans, example of carriers

Achondroplasia

Example of dominant genetic disease that when Homozygous kills the embryo and is only seen in heterozygous individuals.

amniocentesis

type of genetic testing in a fetus; extracts amniotic fluid from the uterus to be grown in a lab, a karyotype of these grown cells can be preformed to determine the genetic makeup of the fetus.

Chorionic Villus Sampling

type of genetic testing in a fetus; extracts a sample of chorionic villus tissue from the placenta, sample is then karyotyped to determine the genetic makeup.

Alpha-fetoprotein

Measured in the mother’s blood, higher level of this protein can determine a possible nervous system defect in the fetus, low levels can indicate down syndrome.

Ultrasound Imaging

gel placed on the mothers stomach allows for an image of the fetus to be depicted.

Fetoscopy

thin needle with a fiber-optic fetal scope is inserted into uterus to look at the fetus.

phenylketonuria

recessive disorder that is best detected in a new born child. results in the improper breakdown of amino acid phenylalanine.

Complete dominance

dominant allele has same phenotypic effect whether present in one or two copies.

Incomplete dominance

some traits fail to have either a dominant or recessive alleles, when varying alleles are both present they fight for phenotypic effect and are shown to be mixed in the phenotype.

Codominance

when neither two alleles have dominance over each other and are both expressed evenly in a subject; shown in AB blood type where the offspring received both A and B alleles and neither showed dominance over the other and both were expressed evenly in the AB blood type.

Pleiotropy

Property in which one gene influences multiple characteristic within an organism

Sickle Cell Disease

Example of pleiotropy where misfigured blood cells trigger other events in the body to lower blood cell count or clot arteries.

Polygenic Inheritance

the additive effects of two or more genes on a single phenotypic character, opposite of pleiotropy.

Chi Square

Numeric value used to determine if the result seen in a generation of offspring was based off of environmental concerns; higher values typically indicate an environmental factor.

Degrees of freedom

When compared to chi square value, can show if the chi square value is significant enough to prove environmental factors. (Possible outcomes -1)

Chromosome Theory of Inheritance

principle that holds that specific genes occupy specific sectors on a chromosome, and it is the chromosomes that undergo independent assortment and segregation, not the genes themselves

Linked Genes

Genes located close together on the same chromosome that tend to be inherited together.

wild-type

refers to traits that are most common in nature

mutant

refers to traits that are less common in nature

recombinant frequency

value for used to show the amount of recombinant offspring over the amount of total offspring. recombinants/total offspring

Genetic Map

Ordered list of the genetic loci (gene location on chromosome) along a chromosome.

Linkage Map

Genetic Map based off of recombination frequencies.

sex chromosomes

X, Y, chromosomes determining gender, can have certain other genes linked to them other than gender.

sex linked gene

gene located on either X or Y sex chromosomes

X-Linked Genes

genes located on the X chromosome

Y-Linked Genes

genes located on the Y chromosome

Mutation

way in which new alleles are able to be created and enter the gene pool

population

group of individuals of the same species that live in the same area and potentially interbreed

gene pool

collection of all copies of every type of allele at every locus in all members of the population.

Microevolution

when frequencies of alleles in a given gene pool fluctuate over the number of generations.

hardy-weinberg equilibrium

Principle that the frequencies of alleles will remain constant in a given population unless there are environmental factors at play.