نتایج جستجو برای: reproduction

تعداد نتایج: 66692  

Journal: :Cold Spring Harbor Perspectives in Biology 2015

2011
Hsiao-ling Lu Sylvie Tanguy Claude Rispe Jean-Pierre Gauthier Tom Walsh Karl Gordon Owain Edwards Denis Tagu Chun-che Chang Stéphanie Jaubert-Possamai

Piwi-interacting RNAs (piRNAs) are known to regulate transposon activity in germ cells of several animal models that propagate sexually. However, the role of piRNAs during asexual reproduction remains almost unknown. Aphids that can alternate sexual and asexual reproduction cycles in response to seasonal changes of photoperiod provide a unique opportunity to study piRNAs and the piRNA pathway i...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه ارومیه 1377

‏‎applications such as high definition viedeo reproduction, portable computers, wireless, and multimedia demand, and ever-increasing need for ligh-frequency high-resolution and low-power analog-to-digital converters. flash, two-step flash, and pipeline convertors are fast but consume large amount of power and require large area. to overcome these problems, successive approximation converter blo...

2010
Kejian Wang Ding Tang Lilan Hong Wenying Xu Jian Huang Ming Li Minghong Gu Yongbiao Xue Zhukuan Cheng

Sexual reproduction is essential for the life cycle of most angiosperms. However, pseudovivipary is an important reproductive strategy in some grasses. In this mode of reproduction, asexual propagules are produced in place of sexual reproductive structures. However, the molecular mechanism of pseudovivipary still remains a mystery. In this work, we found three naturally occurring mutants in ric...

Journal: :American journal of botany 2000
M L Ronsheim J D Bever

Populations of Allium vineale commonly include individuals with very different allocation patterns to three modes of reproduction: sexual flowers, aerially produced asexual bulbils, and belowground asexual offsets. If selection is currently acting to maintain these different allocation patterns there must be a genetic basis for variation in allocation to these three reproductive modes. In addit...

علیزاده, لیلا, عمانی سامانی, رضا,

Rapid development in assisted reproductive techniques has brought hope to many childless couples, while it has created new social, ethical and legal dilemmas. Stored frozen gametes and embryos have led to situations where the surviving spouse wants to create offspring after the person's death. Also, the possibility of sperm retrieval even after 36 hours of death, and getting oocytes from aborte...

1990
S. Mahdihassan

This study scans into past of ancient man and discusses meticulously how the reproductive organ Lingam became sacred object to Hindus and why a sufi wore a phallus shaped head-dress resembling to it. In this manner the author demystifies here the procreation, the law of nature.

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