Test 4 Flashcards
Correcting or replacing mutated genes as a treatment for a genetic disease
Gene Therapy
the oxygen-carrying protein in read blood cells
Hemoglobin
One of the proteins that makes up hemoglobin
beta-globin
A change in the nucleotide sequence of a DNA molecule
Mutation
A mutation that alters a single DNA nucleotide
Point Mutation
A point mutation that changes the amino acid sequence of the encoded protein.
Missense mutations
A point mutation that does not change the amino acid sequence of the encoded protein
Silent Mutations
A shift in the reading frame, such that codons start and end at an alternative position
Frameshift mutations
Any chemical or physical agent that can damage DNA by changing its nucleotide sequence
mutagens
A way to change the sequence of a gene
gene editing
A genome-editing tool based on a natural defense system in bacteria
CRISPER
nonreproductive cells of the body
somatic cells
reproductive cells of the body
germ cells
differently shaped red blood cells that do not flow well through blood vessels, caused by a genetic mutation in the beta-globin gene.
Sickle Cell Disease
Types of mutations
point, frameshift, rearranged DNA
Silent mutation, Missense Mutation, nonsense mutation
Point Mutations
Insertion mutation, deletion mutation
Frameshift Mutations
Inversion mutation, translocation mutation
Rearranged DNA mutations
Change one nucleotide; introduces early stop codon–protein is too short and therefore not functional
nonsense mutation
Insert one or more nucleotides; shifts the reading frame of every codon after the insertion–severely modified sequence makes the protein not functional
Insertion Mutation
Delete one or more nucleotides; shifts the reading frame of every codon after the deletion–severely modified sequence makes the protein not functional
Deletion mutation
A group of DNA nucleotides are flipped to read in reverse order; different amino acid sequences in this location–change in protein shape and function
Inversion mutation
Move segments of DNA from one chromosome to another, fusing portions of different genes together–a significant change in protein shape and function
Translocation mutation
Change one nucleotide to another; no change in amino acid sequence–no change; normal function
silent mutation
Change one nucleotide to another; different amino acid sequence in the location–change in protein shape and function
Missense mutation
UV radiation, X-rays, smoking, pollution
Mutagens
a disease in which cells divide repeatedly and without restraint, in some cases a tumor
Cancer
The process by which a cell reproduces itself; cell division is important for the normal growth, development, maintenance, and repair of an organism
Cell division
The ordered sequence of stages through which a cell progresses to divide; g1, s, g2
Cell Cycle
The stage of the cell cycle in which dividing cells spend most of their time, preparing for cell division; subphases g1, s, g2
Interphase
The two identical DNA molecules that result from the replication of a chromosome during the S phase.
Sister Chromatids
The segregation and separation of replicated chromosomes during cell division
Mitosis
The physical division of a cell into two daughter cells
Cytokinesis
Any substance that causes cancer
Carcinogens
A cellular mechanism that ensures that a stage of the cell cycle is completed accurately
Cell Cycle checkpoints
A type of cell death; often referred to as cellular suicide
Apoptosis
A mass of cells resulting from uncontrolled cell division
Tumor
The specialized region of a chromosome where the sister chromatids are joined; it is critical for proper alignment and separation of sister chromatids during mitosis
Centromere
The Microtubule-based structure that separates sister chromatids during mitosis
Mitotic spindle
Cancers that are caused by non-inherited (acquired) mutations
Sporadic
A gene that codes for a protein that helps cells divide normally
Proto-oncogenes
A gene that codes for a protein that monitors and checks cell cycle progression. When these genes mutate lose normal function
Tumor suppressor genes
A mutated and overactive form of a proto-oncogene drives cells to divide continually
Oncogenes
A noncancerous tumor whose cells will not spread throughout the body
Benign Tumor
A cancerous tumor whose cells can spread throughout the body
malignant tumor
The spread of cancer cells from one location in the body to another
Metastasize
A characteristic of normal cells that prevents them from dividing once they have filled a space and are in contact with their neighbors
contact inhibition
the need for normal cells to be in physical contact with another layer of cells or a surface
anchorage dependence
The growth of new blood vessels
angiogenesis
Treatment using toxic chemicals that kill cancer by interfering with cell division
chemotherapy
The use of ionizing (high energy) radiation to treat cancer
radiation therapy
A cancer therapy that is specific for cancer cells and not harmful to normal cells
Targeted Therapies
A cancer therapy that uses the immune system to recognize and destroy cancer cells
Immunotherapies
An x-ray of the breast
Mammogram
Genes BRCA1 and BRCA2
indicators of breast cancer risk
Located on chromosomes 17 and 13
BRCA mutations
Reasons cells divide
Growth and development, cell replacement, heal wounds
Interphase, Mitosis, Cytokinesis
Cell phases
Preparatory steps before cell division, G1, S, G2 phases, involves growth and duplications of chromosomes
Interphase
Cell grows, makes extra cytoplasm
G1 Phase
DNA replication occurs, chromosomes form identical sister chromatids
S phase
Cell prepares for division
G2 Phase
Chromosomes line up, small fibers attach to centromers on each sister chromatid; one of each sister chromatid ends up in each side of the cell
Mitosis
Enlarged cell splits into two cells, each has full complement of DNA, starts with one parent cell undergoing mitosis, ends with two daughter cells
Cytokinesis
Interphase, Prophase, Metaphase, anaphase, telophase
Phases of Mitosis
Fibers called microtubules shorten, seperating sister chromatids
Anaphase
Daughter cell nuclei are formed
Telophase
Chromosomes are loosely gathered in the nucleus
Interphase
Chromosomes begin to coil up
Prophase
Chromosomes align in the middle of the cell
metaphase
Normally promote cell division and differentiation, can be mutated to become permanently activated, when mutated they become oncogenes
Proto-oncogenes
normally pause cell division, repair DNA, or initiate cell death, can be mutated to become inactivated. Ex. BRCA1 and BRCA2
Tumor suppressor genes
Any of the alternative versions of the same gene that have different nucleotide sequences
Alleles
having two copies of every chromosome
Diploid
A pair of chromosomes that both contain the same genes; the pair is inherited from the mother, the other from the father
homologous chromosomes
The visible or measurable features of an individual
Phenotype
The particular genetic makeup of an individual
genotype
Specialized reproducive cells that carry one copy of each chromosome; sperm and eggs
gametes
having only one copy of every chromosome
haploid
A typed of cell division that generates genetically unique haploid gametes
meiosis
A diploid cell that is capable of developing into an adult organism; formed when a haploid egg is fertilized by a haploid sperm
zygote
An early stage of development reached when a zygote undergoes cell division to form a multicellular structure
embryo
An even in meiosis during which maternal and paternal chromosomes pair and physically exchange DNA segments
recombination
The principle that alleles of different genes are distributed independently of one another during meiosis
Independent assortment
An allele that reveals itself in the phenotype only if a masking dominant allele is not present
recessive allele
An allele that can mask the presence of a recessive allele
dominant allele
having two different alleles for a given gene
heterozygous
having to identical alleles for a given gene
Homozygous
a diagram used to determine probabilities of offspring having particular genotypes, given the genotypes of the parents
Punnett square
An individual who is heterozygous for a recessive allele and can therefore pass it on to offspring without showing any of its effects
carrier
genetic disease caused by a single gene mutation; change in nucleotide sequence of DNA; creates a new mutant allele; allele of the CFTR gene; mutated version fo CFTR that fails to move ions
Cystic Fibrosis
located on chromosomes which are physically transmitted from parent to offspring
Genes
seperates homologous chromosomes instead of sister chromatids, each daughter cell is a haploid, each chromosome still has two sister chromatids
Meiosis I
Seperates sister chromatids, four haploid daughter cells, develop into an egg or sperm
meiosis II
ovaries in females; testes in males
gonads
A class of sex hormones, including testosterone, that are present in higher levels in men and cause male-associated traits like deep voice, growth of facial hair, and defined musculature
androgens
A class of sex hormones, including estrodol, that are present in higher levels in women than in men and that support female sexual development and function
Estrogens
paired chromosomes present in both males and females; all chromosomes except the X and Y chromosomes
autosomes
Paired chromosomes that differ between males and females; females have XX and males have XY
sex chromosomes
A phenotype determined by an allele on an X chromosome
X-linked traits
A visual representation of the occurence of phenotypes across generations
Pedigree
The comparison of sequences on the Y chromosomes of different individuals to examine paternity and paternal ancestry
Y-Chromosome analysis
A form of inhertiance in whch heterozygotes have a phenotype that is intermediate between the two homozygotes
incomplete dominance
A form of inheritance in which the effects of both alleles are displayed int he phenotype of a heterozygote
codominance
variation in a population showing an unbroken range of phenotypes rather than discrete categories
continuous variation
A trait whose phenotype is determined by the interaction among alleles of more than one gene
polygenic trait
An interaction between genes and the environment that contributes to a phenotype or trait
multifactorial
changes in gene expression that are not based on changes int he DNA sequence
epigenetics
An abnormal number of one or more chromosomes either extra or missing copies
aneuploidies
The failure of chromosomes to seperate accurately during cell division; leads to aneuploid gametes
nondisjunction
Having an extra copy of chromosome 21; also known as down syndrome
Trisomy 21
A procedure that removes fluid surrounding the fetus so as to obtain and analyze the chromosomal makeup of fetal cells
amioncetsis
The chromosomal makeup of cells, analysis can be used to detect chromosomal disorders prenatally
karotype
signals the testes to develop
SRY gene on the Y chromosome
A, B, and O
Blood group Allele
can give to any other bllod type
Type o and RH -
a process that tends to decrease gene expression
methylation
