GENETICS

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Chiasmata
Site of crossing over
Eugenics
Control of mating to ensure that “defective” genes of troublesome individuals will not be passed on to future generations. Positive=promotion of breeding people with favorable genes. Negative=discouragement breeding among those with undesirable traits
Transmission genetics
The branch of genetics concerned with the mechanisms by which genes are transferred from parent to offspring.
molecular genetics
Study of DNA structure and function on the molecular level
DNA
A macromolecule usually consisting of antiparallel polynucleotide chains held together by hydrogen bonds, in which the sugar residues are deoxyribose. It is the primary carrier of genetic information.
Central Dogma
the concept that states that, in cells, information only flows from DNA to RNA to proteins
population genetics
Examines the frequency, distribution, and inheritance of alleles within a population
variation
an organism that has characteristics resulting from chromosomal alteration.
Meiosis
Cell division that produces gametes
Mitosis
1 diploid parent cell splits into 2 identical diploid daughter cells.
Somatic cell
All cells in your body except for your sex cells
Gamete
A haploid sex cell, formed during meiosis.
Crossing over
The exchange of corresponding segments of the chromatids of two homologous chromosomes during meiosis.
Stages of Meiosis
Interphase, Prophase I, Metaphase I, Anaphase I, teleophase I, cytokinesis, Prophase II, Metaphase II, Anaphase II, Telophase II, cytokinesis
Stages of Mitosis
prophase, metaphase, anaphase, telophase
Prophase
chromatin condenses into chromosomes
Metaphase
nuclear envelope disappears, chromosomes align at the equatorial plate.
Anaphase
sister chromatids separate, centromeres divide
Telophase
chromatin expands, cytoplasm divides
cell cycle
sum of the phases of growth of an individual cell type; dived into G1(growth 1), S (DNA synthesis), G2 (growth 2), and M (mitosis)
homozygous
An organism that has two identical alleles of a gene for a given character
heterozygous
Describes two different alleles at a specific locus.
genotype
set of alleles present in the genome of an organism
Chromosome
double stranded DNA molecule packaged by histone & scaffold proteins.
homologous
Chromosomes that share centromere position, share overall size, contain identical gene sets at matching positions (loci ) .
sister chromatids
Replicated forms of a chromosome joined together by the centromere and eventually separated during mitosis or meiosis II.
Allele
An alternative form of a gene.
genome
collection of all genetic material of organism
Gregor Mendel
“Father of genetics;” used statistical analysis of breeding experiments to arrive at the concept of a gene; developed the law of dominance, genes and alleles, and the segregation of alleles
Punnett Square
A chart that shows all the possible combinations of alleles that can result from a genetic cross
test cross
cross with homozygous recessive organism
genotypic ratio
the ratio of the genotypes that appear in offspring.
phenotypic ratio
a ratio that shows the varied outcomes that results from a genetic cross and is based on physical appearance alone
Laws of Mendel
1. Discreet units of dominance and recessive-ness, 2. Segregation of traits, 3. random (independent) assortment, did not discover crossing over
dihybrid cross
a genetic cross involving two characters in which the parents possess different forms of each character (e.g., yellow, round X green, wrinkled peas)
monohybrid cross
a genetic cross between two individuals involving only one character. (AA x aa)
Advantages of pea plants
each flower has both sperm and egg organs; easy cross-pollination; mating can be controlled
the function of proteins
cell growth, repair, maintenance. Enzymes and hormone. Fluid and electrolyte balance.
genetic code
A set of rules that defines how the four-letter code of DNA is translated into the 20-letter code of amino acids, which are the building blocks of proteins.
RNA triplets
codon
the structure of nucleic acid
DNA is a polymer made of repeating subunits called nucleotides
DNA microarray
Technique used to screen a single sample for a vast range of different nucleotide sequences stimultaneously; it is often used to study gene expression
inheritance
genes are packaged into chromosomes, and chromosomes are passed on from on cell to the next
Q arm
long arm
P arm
short arm
centromere
separates Q arm and P arm
SNP
single nucleotides polymorphous. associated with mutations that are allowed for genetic variation.
enzymes
cut proteins to alter gene expression
mitosis and meiosis are
mechanisms by which cells distribute the genetic information contained in their chromosomes to progeny cells in a precise, orderly fashion.
Mendel’s work on pea plants established
the principles of the transmission of genes from parents to offspring and established the foundation for the science of genetics
Recombinant DNA technology
allows genes from one organism to be spliced into vectors and cloned, serving as the basis for a far-reaching technology used in molecular genetics.
the use of model organisms
has advanced our basic understanding of genetic mechanisms and , coupled with recombinant DNA technology, has been used to develop models for human genetic diseases.
genetic engineering
A technology that includes the process of manipulating or altering the genetic material of a cell resulting in desirable functions or outcomes that would not occur naturally.
cytogenetics
study what is happening in an entire cell
recessive
an allele that is masked by a dominant allele. The dominant gene is always expressed in heterozygous.
P
parental generation
F1
first filial generation (offsprings from parents)
F2
Second filial generation of genetic code (F1 offspring)
locus
A specific place along the length of a chromosome where a given gene is located.
Categories: Genetics