division

Zygote

.... Meiosis that takes place within the first few division s after zygote formation; thus all stages in the life cycle other than the zygote are haploid . Full article >>> Zygote Mostly diploid cell formed by union of two gametes or reproductive cells . Ovum (female gamete ) fert...

Yolk

...l article >>> By the end of the 8th division most nuclei have migrated to the surface, surrounding the yolk sac (leaving behind only a few nuclei, which will become the yolk nuclei). Full article >>> Lecithotrophic larva . A planktonic-dispersing larva that lives off yol...

Vertebrates

...sed of multicellular organ isms divided into two division s: vertebrates and in vertebrates , who obtain their food from external sources and reproduce sexual ly or asexual ly ... Full article >>> Two class es of intracellular lectins involved in glycoprotein trafficking are present ...

Vector

...ottom). 1 Chromosomal DNA . 2 Plasmid s. 3 Cell division . 4 Chromosomal DNA with integrated plasmid s ... Full article >>> Vector 1 This piece of DNA contained (among other things): the DNA of adeno-associated virus (AAV) a gene encoding a protein containing two domain s: ....

Vectors

...ottom). 1 Chromosomal DNA . 2 Plasmid s. 3 Cell division . 4 Chromosomal DNA with integrated plasmid s ... Full article >>> Vectors in gene therapy Virus es attack their hosts to insert their genetic material into the genetic material of the host . This genetic material cont...

Vascular plants

...62; in the sperm plant s ( Sperm atophyta ) division belonging to the vascular plants ( Tracheophyta ) phylum of the plant kingdom . They are divided into two subclasses: Dicot s ( Magnoliopsida such as magnolia, dandelion, roses, violet) and Monocot s ( ... Full article >>> T...

Variety

Variety An indefinite sub division of a species usually applicable to a morphological variant or variant group, a form which is not typical but is not sufficiently recognizable to be designated by a specific name, a variant in color or in habitat . Full article >>> ...

Unicellular

... primarily reproducing asexual ly by simple cell division or by budding of a parent cell . yolk The stored food in egg cells that nourishes the embryo . Full article >>> : Unicellular , photosynthetic (photo- autotroph ) prokaryote (in the Kingdom Monera ). Formerly known ...

Tumor suppressor

...a tumor suppressor regulating cell growth and division . If suppressor genes are lost or damaged by mu...r suppressor genes Genes that normally keep cell division under control, preventing the cell from responding to internal and external commands to divide. ...

Tumor

...too many cells resulting from uncontrolled cell division . Full article >>> Tumor Suppres... tumor suppressor regulating cell growth and division . If suppressor genes are lost or damaged by mutation , uncontrolled cell growth can occur, res...

Tubulin

...r suppressor genes Genes that normally keep cell division under control, preventing the cell from respond...at appear to move eukaryotic chromosomes during division . The microtubule apparatus that controls chromosome movement during mitosis and meiosis . A B ...

Trisomy

... of twice. Caused by nondisjunction during cell division . Related Terms: Diploid ... Full article >>> Trisomy 18 (Edward Syndrome) Trisomy 18 is associated with mental and physical retardation, skull and facial abnormalities, defects in all organ systems, and poor muscle tone. Mea...

Transformation

...es in a lymph ocyte associated with the onset of division . Also used to denote the change to the autonomously dividing state of a cancer cell ... Full article >>> Transformation . In prokaryotes , the natural or induced uptake and expression of a foreign DNA sequence --typically a ...

Tracheophyte

...62;>> Tracheophyte any plant of the division Tracheophyta, comprising all forms of vascular plants , Pteridophytes and Sperm atophytes. transverse Lying or placed across or crosswise ... Full article >>> Non tracheophyte plant s including the liverworts , hornworts and m...

Thorax

...;>> thorax . The second of three major division s in the body of an insect, and the one bearing the legs and wings. thurberia weevil. A race of the boll weevil that feeds on wild cotton. tiller. Branch stem of a grass plant . Full article >>> thorax 1. in vertebrates it is t...

Tetrad

...atid s making up a chromosome -pair at the first division of meiosis . Related Terms: Haploid ... Full ...alysing the four products from individual meiotic division s. Tetrad The four products of a single meiosis . Full article >>> tetrad [Gk. ...

Telophase

telophase the stage of cell division that begins when the anaphase chromosomes rea...Introduction to mitosis and the process of cell division . Full article >>> Telophase The nuclear membrane reappears. The chromosomes un...

Taxon

...ticle >>> Order : A taxon omic sub division that contains groups of related families or superfamilies; usually ending in -ptera in insects. Overwinter: A period of rest or hibernation by which insects survive the winter. Full article >>> : A major taxon in the Kingdom Prot...

T cell

...cle >>> Definition: A two-part cell division process in organ isms that sexual ly reproduce,... : the growth tissue ; the location of most cell division of vascular plants . mesoderm : one of three germ layers that develops to become the muscle s an...

Syngamy

... together with syngamy . It is a form of nuclear division by which a diploid parent produces four haploid daughter cell s. Full article >>> The fusion of nuclei of two cells , as part of syngamy . karyokinesis Division of the nucleus during the cell cycle . Full article >&...

Syncytium

...i. Full article >>> After the 10th division the pole cells form at the posterior end of t...ne from the syncytium . Finally, after the 13th division cell membrane s slowly invaginate, dividing the syncytium into individual somatic cells . Full...

Synapsis

...hromosomes during prophase of the first meiotic division , when crossing over occurs. Normally syndesis s...ome pairs during prophase of the first meiotic division , when crossing over occurs. T Taq polymerase . A heat-stable DNA polymerase isolated from the ...

Symbiosis

...l association. sympathetic nervous system : a sub division of the autonomic nervous system that prepares the body for an emergency. Full article >>> symbiosis -- n. A relationship between two organ isms that live in intimate contact with each other; includes mutualism (both organ isms...

Suppressor

... it, p53, can result in loss of control over cell division and thus cancer . Full article >>> In class I mutants, no mutation was evident in trpA -- evidently a suppressor mutation occured (a mutation in another gene , usually t RNA , to compensate for another mutation .) In the ...

Stem

...bone marrow that produce lymphocytes by mitotic division . sternum The breastbone. Full article >>> STEM -LOOP - A feature of RNA secondary structure , in which two complement ary, inverted sequence s which are separated by a short-intervening sequence within a single strand of RN...

Stem cell

...g bones that give rise, by differentiation and division , to red blood cells and all of the different ty...bone marrow that produce lymphocytes by mitotic division . sternum The breastbone. Full article >>> The construct is then taken up by embryo ...

Start codon

...bone marrow that produce lymphocytes by mitotic division . sternum The breastbone. Full article >>> START CODON - See INITIATION CODON . STEM -LOOP - A feature of RNA secondary structure , in which two complement ary, ... Full article >>> Start codon : That codon at...

Stapes

...bone marrow that produce lymphocytes by mitotic division . Full article >>> stapes Stirrup-shaped innermost bone of the middle ear. starch A polysaccharide composed of a thousand or more glucose molecule s; the chief food storage material of most plant s. Full article >>...

Sporophyte

...ired chromosomes to dissociate during the first division of meiosis . Full article >>> This involves an alternation between two generations: a haploid stage, called the gametophyte , and a diploid stage, called the sporophyte . The sporophyte is short-lived and remains dependent on...

Spontaneous generation

...sed of multicellular organ isms divided into two division s: vertebrates and invertebrates , ... Full article >>>...

Spore

spore mother cell a cell , which by cell division s, produces usually four spore s Source: Noland, .... Full article >>> The reduction division process by which haploid gametes and spore s are formed, consisting of a single duplication ...

Splicing

...splicing can be very different between the major division s. Eukaryotes splice many protein -coding messenger RNA s and some non-coding RNA s. Full article >>> RNA splicing a process or removing introns from nuclear RNA , thus converting it into a functional m RNA Source: Jenkins...

Spinal nerve

...;>> The spinal nerve s The posterior division s The anterior division s The thoracic nerves The lumbosacral plexus The sacral and coccygeal nerves ... Full articl...

Spindle Fibers

...otein fibers formed during prophase of nuclear division ; chromosomes attach to these fibers at the cen...spindle fibers attach during mitotic and meiotic division . Chemotherapy. A treatment for cancer s that involves ad- ministering chemicals toxic to malignant...

Spermatogonia

... rise to sperm atocytes through repeated mitotic division s. Full article >>> Spermatogonia ...t, by enlargement, differentiation , and meiotic division , become sperm atocytes, then spermatids , ... Full article >>> Stem cell s (Type ...

Spermatids

...of the spermatogonia ; they give rise by meiotic division to the spermatids . spermatogonia [Gk. sperm ...s is a primary sperm atocyte. The first meiotic division produces two secondary sperm atocytes and the second division produces spermatids , which matur...

Spermatid

spermatid male cell that arises by division from a secondary sperm atocyte and that later gi... cell that results from secondary sperm atocyte division . As a result of meiosis , each spermatid contains only half of the genetic material present in...

Sperm cells

...male testes . S phase: the phase within the cell division cycle in which DNA is replicated. spinal cord ... the formation of egg and sperm cells , a cell division occurs without prior doubling of the number of chromosomes . Full article >>> Sper...

Sperm

sperm atid male cell that arises by division from a secondary sperm atocyte and that later gi...he formation of egg and sperm cells , a cell division occurs without prior doubling of the number of chromosomes . Full article >>> capa...

Somatic cells

... meiosis - reduction ]. Two consecutive nuclear division s whereby the resultant daughter nuclei contain ha... at time of gametogenesis . Synonym: reduction division . Full article >>>...

Somatic cell

... meiosis - reduction ]. Two consecutive nuclear division s whereby the resultant daughter nuclei contain ha... at time of gametogenesis . Synonym: reduction division . Full article >>>...

Somatic

... system [Gk. soma, body] The branch of the motor division of the vertebrate peripheral nervous system c... >>> sensory somatic system: a sub division of the peripheral nervous system that carries impulses from the external environment and the ...

Sister Chromatids

..... Full article >>> In the, second division ( meiosis II), sister chromatids segregate. I...ome to which spindle fibers attach during cell division at which two sister chromatids (the two exact copies of each chromosome that are formed after ...

Sister chromatid

... . Full article >>> In the, second division ( meiosis II), sister chromatid s segregate. ...ome to which spindle fibers attach during cell division at which two sister chromatid s (the two exact copies of each chromosome that are formed after...

Siphon

...described in terms of size. Usually the following division s are used: ... Full article >>> Siphon ophores. A group of specialized hydrozoan cnidarians, consisting of large planktonic polymorphic colon ies ... Full article >>> siphon ogamy A reproductive process in seed plan...

Sexual

...lves a single individual. Reproduction by cell division , fragmentation or budding . Association ... Ful...cle >>> Definition: A two-part cell division process in organ isms that sexual ly reproduce, which results in gametes with one-half the numb...

Sexual reproduction

...lves a single individual. Reproduction by cell division , fragmentation or budding . Association ... Full article >>> Union of gametes in sexual reproduction . Related Terms: Gamete Mature male or female reproductive cell ( sperm or ovum ) with a haploid set of chromosomes (23...

Sex cells

...ticle >>> Meiosis a special cell division resulting in sex cells with half as many chrom... Meiosis : The process of two consecutive cell division s in the diploid progenitors of sex cells . Meiosis results in four rather than two daughter c...

Serum

...;> A serum protein that stimulates cell division when it binds to its cell -surface receptor . A...;> A serum protein that stimulates cell division when it binds to its cell -surface receptor . Growth phase (curve). The character istic periods ...

Sepal

...ting adjacent segment s, as in annelids, or body division s, as in chaetognaths. septate Divided by crosswalls into cells . Full article >>> sepal . One of the outermost flower structures which usually enclose the other flower parts in the bud. sequential sampling. A sampling method in ...

Sensory neurons

...nal environment . sensory somatic system: a sub division of the peripheral nervous system that carries impulses from the external environment and the sense s. Full article >>> sensory neurons Neuron s that carry signals from receptor s and trans mit information about the enviro...

Sense

...o 10 copies per organelle . Mitosis -- nuclear division . Full article >>> non sense codo... >>> sensory somatic system: a sub division of the peripheral nervous system that carries impulses from the external environment and the ...

Segregation

...r. Segregation may occur at the first or second division of meiosis , or at the first mitosis after meiosis (postmeiotic segregation ). Full article >>> : The situation referring to segregation of two or more genes together as a unit. Genetic linkage is thought to arise to accommo...

Segregating

...as a single copy in each bacterium are, upon cell division , in danger of being lost in one of the segregati...s. Full article >>> After the 10th division the pole cells form at the posterior end of the embryo , segregating the germ line from th...

Seedless vascular plants

seedless vascular plants : the division Pteridophyta that includes the ferns. semen : a fluid secretion containing sperm and secretions from the prostate gland , seminal vesicles , and Cowper's glands. Full article >>> vascular plants ( tracheophytes ) seedless vas...

Segment

...ami. Full article >>> segment a division ; a section. segregation the separation of homologous chromosomes during anaphase 1 of meiosis , producing gametes containing only one allele of each gene . Full article >>> A segment of DNA with an identifiable physic...

Seed plant

...in Lab 8 Seed Plant Reproduction segment a division ; a section. Full article >>> Early seed plant s are referred to as gymnosperms (naked seeds), as the seed embryo is not enclosed in a protective structure at pollination , with the pollen landing directly on the embryo . Ful...

Seed coat

...like foliage but producing seeds belonging to the division Pteridospermophyta. Full article >>> seed coat A protective coat around the seed , formed from the integument s of the ovule . Covered in Lab 8 Seed Plant Reproduction ... Full article >>> The seed coat deve...

Secretin

...estive processes. seedless vascular plants : the division Pteridophyta that includes the ferns. Full article >>> secretin A hormone produced in the duodenum that stimulates alkaline secretions by the pancreas and inhibits gastric emptying. secretion The release of a substance in re...

Seed

...like foliage but producing seeds belonging to the division Pteridospermophyta. seeding In mari culture , the...sperm atogonium and that will undergo two meiotic division s to become four spermatids . Full article >>> In peas, the locus for seed textu...