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Unusual Plant Defenses
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Plants have evolved a remarkable array of strategies to defend themselves against herbivores, and one such strategy involves attracting insects that act as natural enemies to these plant-eating pests. The fascinating interplay between plants, insects, and the chemical signals they utilize continues to captivate researchers in the field. In the case of the beet armyworm caterpillar, scientists have discovered that its saliva contains a chemical called volicitin, which plays a crucial role in eliciting a defensive response from the plant. When the caterpillar feeds on corn seedlings, the volicitin triggers the release of chemical signals from the leaves, effectively attracting parasitic wasps. These wasps, in turn, prey on the caterpillars, pr ...
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2055 |
bio_man |
11 months ago |
Important but Disappearing Reflexes
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Infants are born with reflexes that support their survival. Newborns are making adjustments to living outside of the womb and do not have time to worry about survival. Fortunately, these reflexes support them in the first few months of life. One reflex is the rooting reflex. This reflex occurs when the cheek or mouth is stroked and results in the baby turning its head toward the stroke. This reflex helps the baby find the nipple when it is time to eat. This reflex disappears around 4 months of age. Another reflex is the sucking reflex. Whenever something touches the roof of the baby’s mouth, it will begin to suck. While this reflex is active before birth, babies that are born prematurely sometimes have difficulty coordinating their sucking ...
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2626 |
bio_man |
A year ago |
Newborns injected with vitamin K, is it necessary?
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Vitamin K is a fat-soluble vitamin necessary mainly for the formation of blood clots. Without this vitamin, bleeding would not stop. Vitamin K is given as an injection to newborns to prevent vitamin K deficiency bleeding, since the level of blood clotting factors of newborn babies are roughly 30–60% that of adult values. The reason for this discrepancy is due to poor transfer of the vitamin across the placenta, and thus low fetal plasma vitamin K. Occurrence of vitamin K deficiency bleeding in the first week of the infant's life is estimated at 0.25–1.7%, with a prevalence of 2–10 cases per 100,000 births. Since the vitamin is found in human milk and supplemented in infant formula, the concentration of vitamin K naturally rises within th ...
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4667 |
bio_man |
2 years ago |
An amazing reaction happens when a plant gets hurt
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The short clip above shows what happens to an injured plant when a nibbling insect attacks the leaves of a plant: the entire plant is alerted to begin anticipatory defense responses.Working in the model plant Arabidopsis, researchers recently showed that a systemic signal begins with the release of glutamate, which is perceived by glutamate receptor–like ion channels upon injury to a leaf. The ion channels then set off a cascade of changes in calcium ion concentration that propagate through the phloem vasculature and through intercellular channels called plasmodesmata. This glutamate-based long-distance signaling is rapid; within minutes, an undamaged leaf can respond to the fate of a distant leaf. If plants react to injury more similarly to ...
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1087 |
bio_man |
5 years ago |
What are the most poisonous plants?
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Plants are essential for any ecosystem, being both a food source and habitat for living things. Although plants are stationary, many are dangerous to touch or eat, making you sick or cause a bad reaction. Some of the most poisonous plants are described below: Abrus Precarious or Rosary Pea (Left) This plant has beans that contain a deadly poison. Ironically, their seeds are often used in jewelry and rosary making, but are not harmful when touched, only if chewed or scratched. The poison is known to stop protein synthesis, leading to organ failure. Ricinus Communis or the Castor Bean (Center) The castor bean plant comes from Africa and its seed is the source of castor oil used all over the world. However, the seeds contain a deadly poison called ...
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10543 |
bio_man |
7 years ago |
This carnivorous plant counts to avoid being tricked
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Unlike conventional plants, the Venus flytrap copes with poor soil by eating bugs! But the cost of insect hunting is high. Catching prey requires Dionaea muscipula to snap down quickly and then carry out the energy-intensive process of digestion. To balance the costs and benefits of eating meat, the plants have developed a counting system to identify real prey from false alarms, according to a new study. To understand how the flytrap distinguishes a potential food source from a false alarm like a raindrop, researchers observed the electrical and chemical response of the plant to touch stimulation. In order to mimic insect prey, the scientists stimulated the hairlike sensors located on the plant’s trap. Touching the sensors two times quick ...
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16810 |
duddy |
8 years ago |
Incredible, these ants can build live bridges with their bodies
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Army ants ( Eciton hamatum, shown above) can form living bridges without any oversight from a "lead" ant and with a clear cost-benefit ratio. The ants will create a path up to the point when too many workers are being diverted from collecting food and prey. Bridges will be the length of 10 to 20 ants - only a few centimeters, but swarms form several bridges a day, which save collective energy and maximize foraging time. The ants exhibit a level of collective intelligence that could provide new insights into animal behavior. Watch the video found here: http://phys.org/news/2015-11-ants-bridges-bodies-video.html ...
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3332 |
duddy |
8 years ago |
This plant contains 27 times more chromosomes per cell than humans
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It's true, the adder's-tongue ferns ( Ophioglossum) pictured above has the highest chromosome count of any known living organism, with 1,262 chromosomes. In comparison, most species have far fewer chromosomes (i.e. humans have 46, 23 pairs). However, the number of chromosomes doesn't suggest that this species is more complex - after all, it's a plant! Some organisms, like this plants can self-fertilize, therefore they end with extra chromosomes. Over many generations, these chromosomes accumulate, hence the large number found in Ophioglossum. ...
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7093 |
duddy |
8 years ago |
Leaves are packed with chlorophyll
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Did you know that there are about half a million chloroplasts (the organelle in plant cells responsible for photosynthesis) in a square millimeter surface area of a leaf! And if that's not enough, photosynthesis makes an estimated 160 billion tonnes of carbohydrates per year. No other chemical process on Earth can match the output of photosynthesis.
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23956 |
duddy |
8 years ago |
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