Glossary Flashcards
Prokaryotic Cell
No nucleus, DNA is in region called nucleoid (not membrane bound)
Circular genome
No membrane bound organelles
✅ Ribosomes
Eukaryotic Cell
Nucleus and membrane bound organelles
Linear genome
✅ Ribosomes, also rough ER
Cytoskeleton: microtubules important in cell division
Centrioles also important in cell division
Cell Division
A parent cell replicates and divides into two daughter cells
Binary Fission
Prokaryotic cell division
Mitosis
Typical cell division in eukaryotes
Produces two genetically identical diploid cells
For growth and repair
Mitosis stages: PPMAT
Prophase, Prometaphase, Metaphase, Anaphase, Telophase, (cytokinesis)
Meiosis
Unique type of cell division in eukaryotes to produce gametes,
Produces four genetically distinct haploid cells
Meiosis I: PMAT I
Meiosis II: PMAT II
PMAT: Prophase, Metaphase, Anaphase, Telophase (and cytokinesis)
Cell Cycle
Interphase (majority of the cycle):
G1-
S-
G2-
Mitotic Phase: mitosis then cytokinesis
Histones
Proteins that DNA strands wrap around
Chromatin
Complex of DNA and proteins (mainly histones) that make up chromosomes
Centromere
Region where the chromatids are most closely attached
Centriole attaches to centromere in cell division
Diploid
Pairs of homologous chromosomes within each cell
Humans have 23 pairs
Crossing Over
Chromosomes exchange large sections between pairs
Occurs during prophase I of meiosis I
Crossing over region is called chaismata
Tetrad
The product of homologous pairs of chromosomes binding together during synapsis
Chiasmata
Crossing over region on chromosome
Gene
A discrete unit of hereditary information consisting of a specific nucleotide
sequence in DNA
A factor of inheritance controlling a trait
Locus
A specific spot on a chromosome where a given gene is located
Allele
Alternative versions of a gene
Homozygous
Having identical alleles for a gene
Heterozygous
Having two different alleles for a gene
Dominant Allele
The allele that is fully expressed in the phenotype of a heterozygote
Recessive Allele
The allele that is not expressed/masked in the phenotype of a heterozygote
Phenotype
The observable traits of an organism determined by its genes
Genotype
Genetic makeup/set of alleles of an organism
Monohybrid
Single gene of interest
Dihybrid
Two genes of interest
Independent Assortment
The alleles of different genes segregate/assort independently of each other into gametes
Incomplete Dominance
One allele is partially/incompletely dominant over the other
Phenotype is midway between homozygotes
Co-Dominance
The heterozygote expresses the
phenotypes of both homozygotes
Neither allele is dominant
Non-Dysjunction
Chromosomes fail to seperate in cell division
Pseudo-Autosomal Region
Region on X and Y chromosomes where alleles for the genes are inherited in a similar way to autosomal alleles
(on the tips of the chromosomes)
Barr Body
Condensed inactive X chromosome that attaches to the inner surface of nuclear envelope in somatic cells
