What is reproduction what is its effects Offline till february so take points now
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Answer:
The harmful effects of exposure to environmental contaminants on reproduction and development in wildlife populations have been reported in the scientific literature for many years. Reported reproductive disorders in wildlife have included morphologic abnormalities, eggshell thinning, population declines, impaired viability of offspring, altered hormone concentrations. and changes in sociosexual behavior.
Laboratory experiments replicating the adverse effects of exposure to the potent synthetic estrogen diethylstilbestrol (DES) during critical periods in development (Newbold 1995; also see Appendix) have focused attention on the potential of chemicals with estrogenic properties to cause developmental and reproductive hazards.
The adverse consequences of prenatal exposure to DES on the female genital tract in humans have been reviewed in detail by Herbst and Bern ( 1981 ) and by Mittendorf (1995); they are the subject of continued, intensive investigation. Whether exposure to environmental hormonally active agents (HAAs) affects animals and humans similarly is not clear, but because exposure of animals to DES causes alterations in male and female offspring, the possibility must be considered that there will be adverse effects from exposure to other compounds with estrogenic, antiestrogenic, or antiandrogenic activity. There are also concerns that exposure to low doses of certain chemicals at critical stages in organ development can result in abnormalities that lead to irreversible changes in the functioning of organ systems later in life. Such damage would not occur through genetic mutations, but by processes that regulate genes during development and cell differentiation. The effects of hormones in adults are usually transient, and hormonal effects disappear when the chemical is not present. By contrast, environmental chemicals that alter gene activity during development would produce effects much harder or impossible to reverse. Evaluating the effects of such chemicals is more difficult than evaluating the effects of chemicals on adults. Effective doses may be lower than effective doses in adults, and the effects are considerably removed in time from the exposure, which can make causal relationships more difficult to establish.
Answer:
Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parents". ... There are two forms of reproduction: asexual and sexual. In asexual reproduction, an organism can reproduce without the involvement of another organism.