Give the differences between mitosis and meiosis. How are the three muscle types alike in structure and function and how are they unalike? What are the organs of the urinary system? Where is the rete testis located? Identify the structure: This structure has both urinary and reproductiv...
The co-existence of males, females and hermaphrodites, a rare mating system known as trioecy, has been considered as an evolutionarily transient state. In nematodes, androdioecy (males/hermaphrodites) as found in Caenorhabditis elegans, is thought to have evolved from dioecy (males/females) throu...
In a diploid organism with 2n = 6 chromosomes, what is the possible number of chromosomes in the gametes when a single non-disjunction event occurs in meiosis 1? A. 2 or 4 B. 2, 3, or 4 C. 2 D. 0 E. 4 In a diploid organism with 2n = 6 chromosomes,...
Macrochromosomes tend to have lower recombination rates (per Mbp) than microchromosomes, presumably because all chromosomes have an obligate crossing-over during meiosis, even if they are physically short (Groenen et al., 2000; Stapley et al., 2008). Within macrochromosomes of zebra finches, ...
Sister chromatid separation and monopolar spindle organization in the first meiosis as two mechanisms of unreduced gametes formation in wheat-rye hybridsAmphihaploidsFISHImmunostainingMitotic-like divisionMonopolar spindleUnreduced gametesUnreduced gametes....
(2) what is the frequency of double-reduction ? Indeed, two sister chromatids could segregate in the same gamete after formation of a tetravalent during meiosis. Consequently, double-reduction creates new types of gametes and modifies the probabilities of each type of gametes in a segregating ...
meiosis is done, followed immediately in the life cycle by fertilization to create a zygote (Fig.1a). Since the animal’s gametes do not normally individually divide, and so do not become multicellular organisms, gametic meiosis, while sexual, is clearly not a reproductive process for animals....
Both QTLs co-localised with genes encoding for putative AtJAS homologs, a key regulator of meiosis II spindle orientation in Arabidopsis thaliana. The function of these candidate genes is consistent with the cytological phenotype of mis-oriented metaphase II plates observed in the parental clones. ...
types (XX/XY, male heterogametic and ZW/ZZ, female heterogametic), or even the same sex chromosome type but on different chromosomes9,10. The increased sex chromosome complement in polyploids could disrupt the sex-determination process, leading to the loss of dioecy, such as the reversal ...
1. INTRODUCTION REGULAR segregation of the homologous chromosomes at meiosis is essential for production of genetically balanced gametes. The synapsis of homologues and its maintenance are prerequisites of regular assortment of the chromo- somes into daughter nuclei. In typical chiasmate meiosis, the ...