Haploid, term

Careie, A., Conti, G, Conti, L. Crebelli, R. (1985) Assays in Aspergillus nidulans for the indnction of forward-mutation in haploid strain 35 and for mitotic nondisjunction, haploidization and crossing-over in diploid strain PI. In Ashby, J., de Serres, F.J., Draper, M., Ishidate, M., Jr, Margolin, B.H., Matter, B.E. Shelby, M.D., eds. Progress in Mutation Research, Volume 5, Evaluation of Short-Term Tests for Carcinogens. Report of the International Programme on Chemical Safety s Collaborative Study on in vitro assays, Amsterdam, Elsevier Science, pp. 307-312... 

Mehta, R.D., and R.C. von Borstel. Mutagenic activity of 42 encoded compounds in the haploid yeast reversion assay, strain XV185-14C, pp. 414-423. In F.J. de Serres and J. Ashby, Eds. Evaluation of Short-Term Tests for Carcinogens. New York Elsevier/North-Holland, 1981. 

All animal eggs are surrounded by egg envelopes which must be traversed by sperm on their journey to the egg surface. These egg envelopes are known by various terms in different organisms, being called the vitelline layer in sea urchins, the vitelline envelope in amphibians, and the zona pellucida in mammals. The fertilizing sperm must penetrate the egg envelope in order to fuse with the plasma membrane and transfer its haploid set of chromosomes into the cell cytoplasm. 

The number of chromosomes normally present in a plant are arranged in pairs so that the complete set is composed of 2 haploid (N) sets and organisms containing them are termed diploid and represented as 2N. Most normal plants are diploid. 

The combination of alleles inherited from a parent is described as a haplotype, a contraction of the term haploid genotype (CIO). Since there are two representatives of chromosome 6 present in each person, one from each parent, an individual will possess, by definition, two HLA-A genes, two HLA-B genes, two HLA-DR genes, etc. 

When replication is complete, the cell enters the G2 phase. It has a DNA content four times the haploid amount (4C). In most eukaryotic cells, the total time required for Gl, S, and G2 phases will be many hours. During this whole period, which is termed interphase, the chromatin is dispersed throughout the nucleus and is actively engaged in transcription. 

If haploid cells fuse, nuclear fusion follows and a diploid nucleus (one containing two sets, twice the haploid number, of chromosomes) is formed. The immediate product of such a fusion process is termed a zygote. From the zygote develop diploid cells which reproduce vegetatively by budding the nucleus divides mitotically and the cells are said to be in the diplophase. 

For simplicity the genomes of higher cells can be divided into three categories (Walker, 1969). 1. A fast or rapidly reassociating fraction which can contain sequences that are repeated more than 10 times per haploid genome and which can often be shown to be associated with satellite DNA. The term satellite DNA refers to minor DNA components that differ in buoyant density from that of the bulk of nuclear DNA of the... 

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