BIOL 1101-Chapter 8&9 Vocab Flashcards
Binary fission
A means of asexual reproduction in which a parent organism, often a single cell, divides into two genetically identical individuals of about equal size.
Anaphase
The fourth stage of mitosis, beginning when sister chromatids separate from each other and ending when a complete set of daughter chromosomes arrives at each of the two poles.
Cell cycle
An ordered sequence of events (including interphase and the mitotic phase) that extends from the time a eukaryotic cell is first formed from a dividing parent cell until its own division into two cells.
Chromatin
The combination of DNA and proteins that constitutes eukaryotic chromosomes; often used to refer to the diffuse, very extended form taken by chromosomes when a cell is dividing.
Chromosomes
A threadlike, gene-carrying structure found in the nucleus of a eukaryotic cell and most visible during mitosis and meiosis; also, the main gene-carrying structure of a
Crossing Over
The exchange of segments between chromatids of homologous chromosomes during synapsids in prophase I of meiosis; also, the exchange of segments between DNA molecules in prokaryotes.
Cytokinesis
The division of the cytoplasm to form two separate daughter cells.
Diploid cell
In an organism that reproduces sexually, a cell containing tow homologous sets of chromosomes, one set inherited from each parent, a 2n cell.
Gametes
A sex cell; a haploid egg or sperm.
Homologous chromosomes
The two chromosomes that make up a matched pair in a diploid cell.
Interphase
The period in the eukaryotic cell cycle when the cell is not actually dividing.
Meiosis
In a sexually reproducing organism, the division of a single diploid nucleus into four haploid daughter nuclei.
Metaphase
The third stage of mitosis, during which all the cell’s duplicated chromosomes are lined up at an imaginary plane equidistant between the poles of the mitotic spindle.
Mitosis
The division of a single nucleus into two genetically identical nuclei.
Sister Chromatids
One of the two identical parts of a duplicated chromosome in a eukaryotic cell.
Telophase
The fifth and final stage of mitosis, during which daughter nuclei form at the two poles of a cell.
Alleles
An alternative version of a gene.
Chromosome Theory of Inheritance
A basic principle in biology stating that genes are located on chromosomes and that the behavior of the chromosomes during meiosis accounts for inheritance patterns.
Codominant
Inheritance pattern in which a heterozygote expresses the distinct trait of both alleles.
Complete Dominance
A type of inheritance in which the phenotypes of the heterozygote and dominant homozygote are indistinguishable.
Dominant Allele
The allele that determines the phenotype of a gene when the individual is heterozygous for that gene.
Genetics
The scientific study of heredity.
Genotype
The genetic makeup of an organism.
Heterozygous
Having two different alleles for a given gene.
Homozygous
Having two identical alleles for a given gene.
Incomplete Dominance
A type of inheritance in which the phenotype of a heterozygote (Aa) is intermediate between the phenotypes of the two types of homozygotes (AA and aa).
Law of Independent Assortment
A general rule in inheritance (originally formulated by Gregor Mendel) that when gametes form during meiosis, each pair of alleles for a particular characteristic segregate independently of other pairs; also known as Mendel’s second law of inheritance.
Law of Segregation
A general rule in inheritance (originally formulated by Gregor Mendel) that individuals have two alleles for each gene and that when gametes form by meiosis, the two alleles separate, each resulting gamete ending up with only one allele of each gene; also known as Mendel’s first law of inheritance.
P Generation
The parent individuals from which offspring are derived in studies of inheritance; P stands for parental.
Phenotype
The expressed traits of an organism.
Pleiotropy
The control of more than one phenotypic characteristic by a single gene.
Polygenic Inheritance
The additive effects of two or more gene loci on a single phenotypic characteristic.
Recessive Allele
An allele that has no noticeable effect on the phenotype of a gene when the individual is heterozygous for that gene.
