Genetics Flashcards
The study of genes, which are the units of inheritance
Genetics
The carrier of genetic information; single, double-stranded DNA molecule
Chromosomes
Two molecules of double-stranded DNA joined in the center by a centromere
Chromatid
An ordinary chromosome; one that does not determine sex of the individual
Autosome
A chromosome that is causally associated with the sex of an individual
Sex chromosomes
Chromosomes of the same kind
Homologous chromosomes
The position of a gene on its chromosome; the position of a gene on the genetic map
Locus
The region or regions of a chromosome with which the spindle fibers become associated during mitosis and meiosis
Centromere
DNA sequences at the tips of chromosomes that protect the tips of chromosomes from erosion and from sticking to each other
Telomere
The number of chromosomes in gamates
Gametic number
The number of chromosomes in ordinary body cells of an organism
Somatic number
The copying of a specific sequence of DNA to produce the corresponding sequence of RNA (mRNA)
Transcription
The assembly of a new protein molecule using its amino acid building blocks, as specified by mRNA
Translation
Sequence of events in which a body cell duplicates its contents and divides in two
Cell cycle
Somatic cells contain two sets of chromosomes are called
diploid cells
Phase of cell division that the cell is not dividing
- replicate its DNA
- consists of three phases, G1, S, and G2
Interphase
consists of nuclear division (mitosis) and cytoplasmic division (cytokinesis) to form two identical cells
Mitotic phase
Nuclear division
Mitosis
The chromatin fibers change into chromosomes
Prophase
Microtubules align the centromeres of the chromatid pairs at the metaphase plate
Metaphase
The chromatid pairs split at the centromere and move to opposite poles of the cell
Anaphase
Two identical nuclei are formed around the identical sets of chromosomes now in their chromatic form
Telophase
Cytoplasmic division
Cytokinesis
Reproductive cell division
Meiosis
Look alike, paired. chromosomes
Homologous chromosomes
Homologous chromosomes pair
Tetrads
During Meiosis prophase 1, chromatids of homologous chromosomes form chiasmata wherein matching regions break and then reconnect to the other chromosome
Crossing over
Reductive division
Meiosis 1
Two haploid cells with replicated sister chromatids go to form four haploid cells with single, unreplicated molecules of DNAs
Meiosis 2
One chromosomes in each pair came from the mother, and the other from the father
Homologous chromosomes
Each pair of homologous chromosomes
Homologous pair
Human karyotype composed of
22 pairs of autosomes
1 pair of sex chromosomes
Alternative forms of gene that code for the same trait and are at the same location on homologous chromosomes are called
alleles
Same alleles
Homozygous
Different alleles
Heterozygous
Genetic makeup of individual
Genotype
Physical or outward appearance
Phenotype
An allele that dominates or masks the presence of another allele and is fully expressed
Dominant allele
An allele whose presence is completely masked
Recessive allele
Agglutination occurs when the red cell antigens correspond to the antibodies in the antisera
Forward typing
Most common cause of dwarfism
Achondroplasia
The probability of combining different alleles
Punnett square
When an individual is born with chromosomes added or missing
Aneuploidy
Missing 1 chromosome
Monosomy
Have an additional chromosomes
Trisomy
The most common cause of hemolytic disease of the new born with the major antigen Rh or D
Erythroblastosis fetalis
The failure of chromosome pairs to separate properly during cell division
Nondisjunction
