Genetics
The study of inherited variation and traits; the transmission of information
Genes
Units of heredity, sets of biochemical instructions that tell cells how to manufacture proteins. Composed of DNA. A distinct sequence of nucleotides forming part of a chromosome
Cells
Basic units of life. Most contain all of the genetic instructions, but cells differ in appearance and functions
Genome
Complete set of genetic information characteristics of an organism, including protein-encoding genes and other DNA sequences. Contains from 28,000 to 34,000 protein-encoding genes, scattered among three billion DNA bases; a complete set of genetic instruc
Bioethics
A field of study that addresses many personal issues that deal with medical technology
Genomics
the new field of
investigating how genes interact, and
comparing genomes. Considers many
genes at a time. Emphasis is on
single-gene traits and compares
ourselves to other species.
Genetic testing
A test to detect
genes that predispose her to developing addictions for
example, certain cancers, and
inherited forms of Alzheimer disease, etc.
Genetic counselor
Is a very important process of genetic testing who discusses and explains the test results.
DNA microarrays/expression panels
-can determine which
genes are turned on or off in affected cells compared to nonaffected cells of the same type.
DNA
is made up of 4 types bases
adenine (A),
guanine (G),
cytosine (C),
and
thymine (T)
Nucleotide
is made up of a sugar, phosphate group and a nitrogenous base. Three bases code for an amino acid which are the basic building blocks of
proteins.
RNA (ribonucleic acid)
this is sent out of the nucleus and is responsible to
make proteins. The nitrogenous base uracil (U) is used instead of thymine.
Allele
The variants of a gene
Mutations
can arise from changes of the allele that affects the sequence
code; some are harmful and others are helpful; they are a type of polymorphism
Single nucleotide polymorphisms
(SNPs)
single base sites that differ among individuals
Chromosome
A structure, consisting of DNA and protein, that carries the genes; humans have 23 pairs. Numbered in order from largest-smallest and the two left over determine the sex of the baby.
Autosomes
Non sex chromosomes. Humans have 22 pairs
Karyotype
Detect chromosomes abnormalities. Stain chromosomes with fluorescent chemicals that create a picture or pattern
Differentiation
Specialized cells with related functions aggregate and interact to form tissues, which in turn form the organs and organ systems of the individual
Stem cells
specialized cells that retain the ability to differentiate further
Genotype
refers to the alleles that are present; the ingrediants in other words for example, TT, Tt, tt
Phenotype
the visible trait of physical trait ex: brown eyes, black hair, short, tall; alleles expressed
Dominant
Alleles that produce effect when present in just one copy; the uppercase allele
Recessive
Alleles that are masked by the dominant alleles and are only expressed when both chromosomes are present; loser case allele
Pedigree
charts used to study the transmission of genetics in a family; also represents the members of a family and indicates which individuals have particular inherited traits
Population
A group of interbreeding individuals; a large collection of alleles, distinguished by the frequency of particular alleles
Gene pool
All the alleles in a population
Evolution
Changing allele frequencies over a gradual period of time. The more similar the sequence are, the more recently two species diverged from a shared ancestor
DNA similarity in humans
Exceeds 99.9 percent
Race
Defined by fewer than 0.01% of our genes.Members of different races could have more genes in common that members of the same race.
Mendelian traits
Single-gene traits ex: cystic fibrosis, sickle cell disease and huntington disease
OMIM
Online listed and described single gene traits and disorders in humans
Multifactorial traits
A trait that is determined by one or more genes and by
the environment. Also called a complex trait; Ex. breast cancer, bipolar effective
disorder, dyslexia
BRCA1 gene
Causes fewer than 5 percent of all cases of breast cancer. Jewish women with the gene have an 86% chance of breast cancer while other ethnic groups only have a 45% chance. Environmental factors may effect the gene's expression
Genetic determinism
An inherited trait is unchangeable
Absolute risk
The probability that an individual will develop a particular condition
Relative risk
the likelihood that an individual from a particular population will
develop a condition in comparison to individuals in another group; is a ratio of
probability.
Found by the percent of absolute risk of the individual divided by the percent of absolute ri
Risk factor
a threatening situation
Empiric risk
The chance that a disease will occur in a family, based on
experience with the diagnosis, past history, and medical records rather than
theory.
Gene therapy
Replaces a malfunctioning gene in the affected parts of the body, in effect correcting the gene's faulty instructions
Agriculture
The controlled breeding of plants and animals to
select new combinations of inherited traits in livestock, fruits, and vegetable that are useful to us.
Biotechnology
enables researchers to create organisms that harbor genes
that they would not naturally have.
Transgenic
an organism with genes from another species, Example is
golden rice, bt corn
Place the following terms in size order, from largest to smallest, based on the structures or concepts that they represent:
a. chromosome
b. gene poo
c. gene
d. DNA
e. genome
Gene pool, genome, chromosomes, gene, DNA
Difference between an autosome and a sex chromosomes
Autosomes- do not carry genes that determine sex; sex chromosomes- carry genes that determine sex
Difference between genotype and phenotype
Genotype- the allele constitution in an individual for a particular gene; Phenotype- the physical expression of an allele combination
Difference between DNA and RNA
DNA- a double-stranded nucleic acid that includes deoxyribose and the nitrogenous bases (adenine, guanine, cytosine, and thymine); RNA- a single-stranded nucleic acid that includes ribose and the nitrogenous bases (adenine, guanine, cytosine, and uracil),
Difference between recessive and dominant traits
Recessive trait- determines phenotype in two copies; dominant trait- determines phenotype in one copy
Difference between absolute and relative risks
Absolute risk- an individual's personal risk; relative risk- in comparison to another group, is less precise
Difference between pedigrees and karyotypes
Pedigree- a chart of family relationships and traits; Karyotypes- charts of chromosomes
List three ways that inherited disease differs from other types of illnesses
+recurrence risk= predictable for particular individuals in families
+ pre-symptomatic detection= possible
+ different populations have different characteristic frequencies of traits/disorders
Cystic fibrosis is a Mendelian trait; height is a multifactorial trait. How do the causes of these characteristics differ?
Cystic fibrosis- caused by one malfunctioning gene; Height- actions of several genes and environmental influences (such as diet)
Steps of genetic testing
- Research and record family
history
- Provide cell sample
-Sample DNA isolated and
applied to personalized DNA
chips
-Results calculated,
communicated