What is a Cytotype?
The cytotype is a characteristic of a cell. Organisms of the same species with different cytotypes differ in: Karyotype. with different chromosome structure. with different chromosome number, ploidy.
What is minority Cytotype exclusion?
The reproductive handicap in a given generation leads to a greater handicap in the next, the minority cytotype being rapidly excluded from the population. Self-pollination reduces the minority disadvantage and the tempo of the exclusion process as does the immigration of minority type pollen and seeds.
How do p elements work?
Naturally-occurring P elements contain coding sequence for the enzyme transposase and recognition sequences for transposase action. Transposase regulates and catalyzes the excision of a P element from the host DNA, cutting at the two recognition sites, and then reinserting randomly.
What is ploidy in plant breeding?
Polyploids are organisms with multiple sets of chromosomes in excess of the diploid number (Acquaah, 2007; Chen, 2010; Comai, 2005; Ramsey and Schemske, 1998). Polyploidy is common in nature and provides a major mechanism for adaptation and speciation. To understand polyploidy, a few basic notations need be defined.
What is P element called?
Phosphorus
Phosphorus is a non-metal that sits just below nitrogen in group 15 of the periodic table. This element exists in several forms, of which white and red are the best known.
What is the meaning diploid?
Diploid is a cell or organism that has paired chromosomes, one from each parent. In humans, cells other than human sex cells, are diploid and have 23 pairs of chromosomes. Human sex cells (egg and sperm cells) contain a single set of chromosomes and are known as haploid.
Why ploidy is more in plants?
As the chromosome number increased, DNA content per cell, enzyme activity per cell, cell volume, and photosynthesis per cell all increased. It was also reported that the photosynthetic capacity of larger cells in polyploid plants are higher than smaller cells with lower chromosome numbers [5, 6, 43].
What causes ploidy?
Mechanisms of Polyploidy Polyploids arise when a rare mitotic or meiotic catastrophe, such as nondisjunction, causes the formation of gametes that have a complete set of duplicate chromosomes. Diploid gametes are frequently formed in this way.
What is phosphorus number?
Phosphorus is a chemical element with symbol P and atomic number 15.