Group items tagged

Topic: Turgor Pressure Why does a touch me not plant close? Hey!! Don't touch that plant. You will get scared. See, you did not listen to me. Don't worry!! Nothing to be scared about. Let me tell you more about this plant. This plant is called the Mimosa Pudica plant. Another name for it is "Touch Me Not" Plant. When anyone touches this plant, it closes its leaves with the help of pulvini. Pulvini are present at the base of each leaflet. They consist of cells filled with water. This water applies pressure against the walls of the cells. This pressure is called the turgor pressure. It helps the leaflets to stand upright. Now, when we touch a leaflet of the touch me not plant, specific parts of the plant release certain chemicals. These chemicals cause the cells in the pulvini to lose water. When water is lost, there is no more turgor pressure. As a result, the cells collapse, resulting in the closing of leaflets.

It's one of the big mysteries of cell biology. Why do mitochondria-the oval-shaped structures that power our cells-have their own DNA, and why have they kept it when the cell itself has plenty of its own genetic material? A new study may have found an answer. Scientists think that mitochondria were once independent single-celled organisms until, more than a billion years ago, they were swallowed by larger cells. Instead of being digested, they settled down and developed a mutually beneficial relationship developed with their hosts that eventually enabled the rise of more complex life, like today's plants and animals.

Explore some examples of specialized plant and animal cells with the Amoeba Sisters! This video explains how specialized cell structure suits their function.

drag and drop review and comparison of plant and animal cells

Technical details aside, Crispr-Cas9 makes it easy, cheap, and fast to move genes around-any genes, in any living thing, from bacteria to people. "These are monumental moments in the history of biomedical research," Baltimore says. "They don't happen every day." Using the three-year-old technique, researchers have already reversed mutations that cause blindness, stopped cancer cells from multiplying, and made cells impervious to the virus that causes AIDS. Agronomists have rendered wheat invulnerable to killer fungi like powdery mildew, hinting at engineered staple crops that can feed a population of 9 billion on an ever-warmer planet. Bioengineers have used Crispr to alter the DNA of yeast so that it consumes plant matter and excretes ethanol, promising an end to reliance on petrochemicals. Startups devoted to Crispr have launched. International pharmaceutical and agricultural companies have spun up Crispr R&D. Two of the most powerful universities in the US are engaged in a vicious war over the basic patent.

Why elephants aren't riddled with tumors poses a weighty problem for researchers. A new study shows that the animals harbor dozens of extra copies of one of the most powerful cancer-preventing genes. These bonus genes might enable elephants to weed out potentially cancerous cells before they can grow into tumors.

Lesson and Units from Science Box

Collection of Biology resources