Central dogma of biology/Gene

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

RNA

single-stranded nucleic acid that contains the sugar ribose

Transcription

(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA

Translation

Process by which mRNA is decoded and a protein is produced

Replication

Copying process by which a cell duplicates its DNA

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

rRNA

ribosomal RNA; type of RNA that makes up part of the ribosome

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome

initiation of transcription

Attachment of RNA polymerase to the promoter RNA polymerase binds to a promoter start (start!)

elongation (transcription)

RNA polymerase unzips the DNA and assembles RNA nucleotides using one strand of DNA as a template.

termination (transcription

RNA polymerase reaches a terminator sequence (Stop codon) and detaches from the template

AUG

start codon (methionine)

stop codon

UAA, UAG, UGA

silent mutation

A mutation that changes a single nucleotide, but does not change the amino acid created.

missense mutation

A base-pair substitution that results in a codon that codes for a different amino acid.

nonsense mutation

A mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein.

frameshift mutation

mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide

Trisomy 21

condition in which an individual has three number 21 chromosomes, resulting in Down syndrome

Trisomy 18

edward's syndrome; second-most common autosomal trisomy; seen with clenched fists

binary fission

A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size

Tay-Sachs disease

A human genetic disease caused by a recessive allele that leads to the accumulation of certain lipids in the brain. Seizures, blindness, and degeneration of motor and mental performance usually become manifest a few months after birth.

Klinefelter syndrome

A chromosomal disorder in which males have an extra X chromosome, making them XXY instead of XY.

Gregor Mendel

Father of genetics

Pea

Gregor Mendel studied heredity using ___ plants

trait

A characteristic that an organism can pass on to its offspring through its genes.

allele

one of a number of different forms of a gene

gene

A segment of DNA on a chromosome that codes for a specific trait

chromosome

a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.

Homozygous

An organism that has two identical alleles for a trait (XX,xx)

Heterozygous

An organism that has two different alleles for a trait (Xx,xX)

homozygous recessive

tt

homozygous dominant

Both alleles (factors) for a trait are the same and dominant (AA)

Heterozygous (hybrid)

having two different alleles for a trait (Tt)

dominant allele

An allele whose trait always shows up in the organism when the allele is present (XY)

recessive allele

An allele that is masked when a dominant allele is present

Law of Segregation

Mendel's law that states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete

law of independent assortment

the law that states that genes separate independently of one another in meiosis

recessive disorders

Albinism, Cystic Fibrosis, Sickle-cell disease, Tay-Sachs disease

dominant disorders

Achondroplasia, Huntington's disease

complete dominance

a relationship in which one allele is completely dominant over another

incomplete dominance

Situation in which one allele is not completely dominant over another allele

codominance

A condition in which neither of two alleles of a gene is dominant or recessive.

Pleitotropy

Multiple phenotypic effects of genes

polygenic inheritance

combined effect of two or more genes on a single character

chromosome theory of inheritance

A basic principle in biology stating that genes are located on chromosomes and that the behavior of chromosomes during meiosis accounts for inheritance patterns.