test 3 video flashcards

Gene regulation

ability of an organism to control which genes are transcribed in response to the environment

gene expression

process by which a gene produces its product and the product carries out its function

enzymes

Catalysts for chemical reactions in living things

Unpacking DNA

Chromatin packing is used to keep genes turned off

Transcription of a gene

produces an mRNA with a nucleotide sequence complementary to one of the DNA strands

Processing of mRNA

• mRNA edited and processed before translation

Introns removed by spliceosomes

mRNA complex proteins associate to guide export, ensure accuracy for translation

Translation of mRNA

biological polymerization of amino acids into polypeptide chains

Breakdown of mRNA

\-Enzymes in the cytoplasm are on the prowl for digestion. aids in cell regulation.

Breakdown of protein

proteolysis

various changes to polypeptide

One of the levels where gene processing can be shut off

X chromosome inactivation

process that occurs in female mammals in which one of the X chromosomes is randomly turned off in each cell

initiation of translation

mRNA is attached to a subunit of the ribosome, the first codon is always AUG

RNA processing

Modification of RNA primary transcripts, including splicing out of introns, joining together of exons, and alteration of the 5' and 3' ends.

Exons

Coding segments of eukaryotic DNA.

Introns

Noncoding segments of nucleic acid that lie between coding sequences.

mRNA breakdown

by enzymes in the cytoplasm, it's lifetime can vary from hours to months. another opportunity for regulation.

selective protein degradation

important way of controlling protein activity; ubiquitination

DNA unpacking, transcription, RNA processing, mRNA breakdown, translation, protein activation, protein breakdown

seven parts of gene regulation

RNA transport

nuclear pores recognize the processed RNA molecules and allows the molecule to exit the nucleus

protein activation

After translation, polypeptides may be cut into smaller, active products.

homeotic genes

Genes that determine basic features of where a body part is.

embryonic development

The process by which the embryo is formed and develops, until it develops into a fetus.

cloning

A process in which a cell, cell product, or organism is copied from an original source.

nuclear transplantation

A technique in which the nucleus of one cell is placed into another cell that already has a nucleus or in which the nucleus has been previously destroyed.

reproduction cloning

making clones of an organism by using their previous DNA

therapeutic cloning

The cloning of human cells by nuclear transplantation for therapeutic purposes, such as the generation of embryonic stem cells to treat disease.

stem cells

unspecialized cells that are able to renew themselves for long periods of time by cell division, partially differentiated

undifferentiated cells

cells that have not become specialized yet

differentiated cells

These are cells which have become modified and specialized within an organism.

embryonic stem cells

embryonic cells, which can develop into any type of body cell

Placental stem cells

Found in the placenta and develop into specific types of cells

Proto-oncogenes

the corresponding normal cellular genes that are responsible for normal cell growth and division

oncogenes

genes that cause cancer by blocking the normal controls on cell reproduction

Carcinogen

A cancer-causing substance

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

Codon

A specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid

Start codon

AUG

three types of mutations

deletion, insertion, substitution

deletion

A change to a chromosome in which a fragment of the chromosome is removed.

insertion

A mutation involving the addition of one or more nucleotide pairs to a gene.

substitution

A mutation in which a nucleotide or a codon in DNA is replaced with a different nucleotide

virus

A tiny, nonliving particle that invades and then reproduces inside a living cell.

virus replication

Attach, invade, copy, release

HIV

A virus that attacks and destroys the human immune system.

HIV replication

Which means to reproduce more copies, HIV becomes a parasite of helper T cells. HIV alters the helper T cells genetic code to make more viral particles. The T cells nucleus follows the DNAs directions and forms long chains of viral particles enclosed within its membrane.

viroids

small circular RNA molecules that infect plants and disrupt their growth

prions

infectious proteins

Heredity

Passing of traits from parents to offspring

Character

A heritable feature that varies among individuals

Trait

variation in the physical appearance of a heritable characteristic

Hybrids

Offspring of crosses between parents with different traits

monohybrid cross

A cross between individuals that involves one pair of contrasting traits

alleles

Different forms of a gene

homozygous

An organism that has two identical alleles for a trait

heterozygous

An organism that has two different alleles for a trait

dominant alleles

An allele whose trait always shows up in the organism when the allele is present.

recessive allele

An allele that is masked when a dominant allele is present

gamete alleles

carry only one allele for each inherited characteristic. two members of an allele separate during production.

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

genotype

genetic makeup of an organism

phenotype

An organism's physical appearance, or visible traits.

homologous chromosomes

Chromosomes that have the same sequence of genes and the same structure

dihybrid cross

Cross or mating between organisms involving two pairs of contrasting traits

X AND Y

multiply

X OR Y

add

wild-type traits

those prevailing in nature, are not necessarily specified by dominant alleles

pedigree

A diagram that shows the occurrence of a genetic trait in several generations of a family.

autosomes

Any chromosome that is not a sex chromosome

recessive disorders

disorders that occur when a child inherits an allele for the trait from both parents.

dominant disorders

Half of the offspring of parents with a dominant disorder will have the disorder.

carriers

heterozygous individuals who carry the recessive allele but are phenotypically normal

cystic fibrosis

A genetic disorder that occurs in people with two copies of a certain recessive allele; characterized by an excessive secretion of mucus and consequent vulnerability to infection; fatal if untreated.

inbreeding

breed from closely related people or animals, especially over many generations.

Achrondroplasia

a form of dwarfism caused by an autosomal dominant allele

genetic testing

The use of methods to determine if someone has a genetic disorder, will develop one, or is a carrier

incomplete dominance

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

ABO blood groups

Genetically determined classes of human blood that are based on the presence or absence of carbohydrates A and B on the surface of red blood cells. The ABO blood group phenotypes, also called blood types, are A, B, AB, and O.

Co-dominance

situation in which both alleles of a gene contribute to the phenotype of the organism

pleiotropy

The ability of a single gene to have multiple effects.

sickle cell disease

Genetic disorder in which red blood cells have abnormal hemoglobin molecules and take on an abnormal shape.

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.

linked genes

Genes located on the same chromosome that tend to be inherited together in genetic crosses.

crossing over

can separate linked alleles. Produce gametes with recombinant chromosomes, offspring with recombinant phenotypes

recombinant chromosomes

individual chromosomes that carry genes derived from two different parents

recombinant phenotypes

Offspring doesn't look like the parents (got recessive alleles).

linkage maps

maps of the relative locations, or loci, of genes on a chromosome

recombination frequency

the percentage of recombinant offspring among the total

sex determination

males are XY, females are XX

sex-linked gene

gene located on the X or Y chromosome. most human ones on X chromosome

hemophilia

A hereditary disease where blood does not coagulate to stop bleeding

Evolution

Change in a kind of organism over time; process by which modern organisms have descended from ancient organisms.

Taxonomy

The scientific study of how living things are classified

Linnean system

Kingdom, Phylum, Class, Order, Family, Genus, Species

Genus

A group of similar species

Species

A group of similar organisms that can breed and produce fertile offspring.

binomial

A polynomial with two terms

Kingdom, Phylum, Class, Order, Family, Genus, Species

linnean system hierarchy

fixed species

idea that species were fixed in form and were not able to change over time