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Eukaryote

Eukaryote
Eukaryotes can reproduce both asexually through mitosis and sexually through meiosis and gamete fusion. In mitosis, one cell divides to produce two genetically identical cells. In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells each with half the number of chromosomes as the original parent cell (haploid cells). These act as sex cells (gametes – each gamete has just one complement of chromosomes, each a unique mix of the corresponding pair of parental chromosomes) resulting from genetic recombination during meiosis. Cell features[edit] Eukaryotic cells are typically much larger than those of prokaryotes. Internal membrane[edit] Detail of the endomembrane system and its components A 3D rendering of an animal cell cut in half. The nucleus is surrounded by a double membrane (commonly referred to as a nuclear membrane or nuclear envelope), with pores that allow material to move in and out. Vesicles may be specialized for various purposes. Related:  biology

Norfolk Botanical Garden - Celebrating 75 years and still growing Microscope A microscope (from the Ancient Greek: μικρός, mikrós, "small" and σκοπεῖν, skopeîn, "to look" or "see") is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy. Microscopic means invisible to the eye unless aided by a microscope. There are many types of microscopes, the most common and first to be invented is the optical microscope which uses light to image the sample. History[edit] The first microscope to be developed was the optical microscope, although the original inventor is not easy to identify. Rise of modern light microscopy[edit] The first detailed account of the interior construction of living tissue based on the use of a microscope did not appear until 1644, in Giambattista Odierna's L'occhio della mosca, or The Fly's Eye.[4] It was not until the 1660s and 1670s that the microscope was used extensively for research in Italy, The Netherlands and England. Types[edit]

It's Plantin' Time! One of the most anticipated science units in my classroom is our study of life cycles. We spend most of our fourth quarter studying the life cycles of plants, butterflies, frogs, and mealworms. It's one of my most favorite times of the year and one that my kiddos really look forward to! Our end of the year open house falls during this time and we made these flower booklets from myLife Cycle of Plants unit to showcase our plant study. However, we had few glitches! We started out with a parts of a seed lab, observing, writing and comparing predictions about what we would find inside of our seeds. After a couple of days we got this and had to start over! I love how this student included the mold in her diagram! We labeled diagrams of plants and wrote about the job of each plant part. You can grab a copy of these charts in my TPT shop {HERE} We also incorporated some comprehension strategies with this little cause and effect activity. Happy planting, teacher friends!

Micrograph 40x micrograph of a canine rectum cross section. A photomicrograph of a thin section of a limestone with ooids. The largest is approximately 1.2 mm in diameter. The red object in the lower left is a scale bar indicating relative size. Approximately 10x micrograph of a doubled die on a coin, where the date was struck twice. A micrograph, or photomicrograph, is a photograph or digital image taken through a microscope or similar device to show a magnified image of an item. Micrographs are widely used in all fields of microscopy. Types[edit] Photomicrograph[edit] A light micrograph or photomicrograph is a micrograph prepared using an optical microscope, a process referred to as photomicroscopy. Roman Vishniac was a pioneer in the field of photomicroscopy, specializing in the photography of living creatures in full motion. Electron micrograph[edit] An electron micrograph is a micrograph prepared using an electron microscope. Digital micrograph[edit] Magnification and micron bars[edit] Gallery[edit]

Diversity In Nature :: SeenAndShared.com :: Best Quality! Diversity "Diversity is not about how we differ. Diversity is about embracing one another's uniqueness." - Ola Joseph "United we stand, divided we fall." - Aesop (620 -560 B.C.) "Diversity: the art of thinking independently together." - Malcom Forbes "Love the one you're with." - Stephen Stills "Diversity is the magic. The greater the diversity, the greater the perfection." - Thomas Berry "We are eternally linked not just to each other but our environment." - Herbie Hancock "We cannot afford to be separate. . . . "I know there is strength in the differences between us. "Uniformity is not nature's way; diversity is nature's way." - Vandana Shiva "Share our similarities, celebrate our differences." - M. "Diversity is the one true thing we all have in common. Zap this page to your friends with One-Click-Forwarding!

Cell nucleus HeLa cells stained for the cell nucleus DNA with the BlueHoechst dye. The central and rightmost cell are in interphase, thus their entire nuclei are labeled. On the left, a cell is going through mitosis and its DNA has condensed. Because the nuclear membrane is impermeable to large molecules, nuclear pores are required that regulate nuclear transport of molecules across the envelope. The pores cross both nuclear membranes, providing a channel through which larger molecules must be actively transported by carrier proteins while allowing free movement of small molecules and ions. History[edit] Between 1877 and 1878, Oscar Hertwig published several studies on the fertilization of sea urchin eggs, showing that the nucleus of the sperm enters the oocyte and fuses with its nucleus. Structures[edit] Nuclear envelope and pores[edit] Nuclear pores, which provide aqueous channels through the envelope, are composed of multiple proteins, collectively referred to as nucleoporins. Nuclear lamina[edit]

top20biology.com Mitochondrion Two mitochondria from mammalian lung tissue displaying their matrix and membranes as shown by electron microscopy History[edit] The first observations of intracellular structures that probably represent mitochondria were published in the 1840s.[13] Richard Altmann, in 1894, established them as cell organelles and called them "bioblasts".[13] The term "mitochondria" itself was coined by Carl Benda in 1898.[13] Leonor Michaelis discovered that Janus green can be used as a supravital stain for mitochondria in 1900. In 1939, experiments using minced muscle cells demonstrated that one oxygen atom can form two adenosine triphosphate molecules, and, in 1941, the concept of phosphate bonds being a form of energy in cellular metabolism was developed by Fritz Albert Lipmann. The first high-resolution micrographs appeared in 1952, replacing the Janus Green stains as the preferred way of visualising the mitochondria. In 1967, it was discovered that mitochondria contained ribosomes. Structure[edit]

Learn Biology Online For Free with our Huge Collection of Open Courses If you’ve always been interested to learn more about nature and the diversity of life, you can now Learn Biology Online for Free! Free Biology courses are easy to find yet some of the ones you find may not be worth your time. We’ve put together a list of Biology courses from well-respected institutions such as John Hopkins, Yale, MIT, Stanford, and UCLA. MOOCs are Massive Open Online Courses. These are University-level courses that have been put online. Many textbooks to help you learn biology online are now made available for free, in either PDF or Digital Format. We have listed here some of the more popular K-12 Resources available for learning Biology Online. SkilledUp is committed to bringing you all the best open educational resources, and we have curated over 850 online open educational resources for you as part of OpenU.

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