<span>Science knowledge relies on experimental and observational confirmation. Where data is incomplete, new or improved data may well lead to revision of accepted science explanations. In situations where observations are fragmentary, it is normal for scientific ideas to be incomplete, but this is also where the opportunity for making advances may be the greatest.The core ideas of science have been subjected to a wide variety of confirmations and are therefore unlikely to change in the areas in which they have been tested. </span><span>Science knowledge may change due to the development of new techniques for observing investigations (including new technologies), and also through new ways of thinking or framing the questions asked.</span>
<span>The correct answer is that he has injured one of the tendons or ligaments that help keep his knee in place, connecting it to the surrounding muscle and bone. As a result of this injury, his knee is no longer connected to the muscle and bone, thus it wobbled sideways when he started walking. He needs to go to a doctor immediately who can fix his knee so as to prevent further complications - he just needs his knee to be set in place again.</span>
Both asexually and sexually
Guard cells are located in the leaf epidermis and pairs of guard cells surround and form stomatal pores, which regulate CO2 influx from the atmosphere into the leaves for photosynthetic carbon fixation.
Stomatal guard cells also regulate water loss of plants via transpiration to the atmosphere.