Reference Terms
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Egg (biology)
In most birds and reptiles, an egg is the zygote, resulting from fertilization of the ovum. It nourishes and protects the embryo. Oviparous animals are animals that lay eggs, with little or no other development within the mother. This is the reproductive method of many fish, amphibians and reptiles, all birds, the monotremes, and most insects and arachnids.
Reptile eggs, bird eggs, and monotreme eggs, which are laid out of water, are surrounded by a protective shell, either flexible or inflexible.
The 1.5 kg ostrich egg contains the largest existing single cell currently known, though the extinct Aepyornis and some dinosaurs had larger eggs. The bee hummingbird produces the smallest known bird egg, which weighs half a gram. The eggs laid by some reptiles and most fish are even smaller, and those of insects and other invertebrates are much smaller still. The study or collecting of eggs, particularly bird eggs, is called oology.
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Plants & Animals News
December 9, 2025
Dec. 9, 2025 Microscopic fibers secretly shape how every organ in the body works, yet they’ve been notoriously hard to study—until now. A new imaging technique called ComSLI reveals hidden fiber orientations in stunning detail using only a rotating LED light ...
Dec. 9, 2025 Scientists discovered a small protein region that determines whether plants reject or welcome nitrogen-fixing bacteria. By tweaking only two amino acids, they converted a defensive receptor into one that supports symbiosis. Early success in barley ...
Dec. 8, 2025 Researchers revealed that the microbial metabolite TMA can directly block the immune protein IRAK4, reducing inflammation and improving insulin sensitivity. The molecule counteracts damage caused by high-fat diets and even protects mice from sepsis. ...
Dec. 8, 2025 Scientists found that kale’s prized nutrients are hard for the body to absorb unless they’re eaten with oil. Cooking doesn’t improve absorption, but adding oil-based dressings—or even more advanced nanoemulsion sauces—does. These ...
Dec. 7, 2025 Researchers successfully implanted a genetically modified pig liver into a human, proving that such an organ can function for an extended period. The graft supported essential liver processes before complications required its removal. Although the ...
Dec. 4, 2025 Scientists have captured a never-before-seen, high-resolution look at influenza’s stealthy invasion of human cells, revealing that the cells aren’t just helpless victims. Using a groundbreaking imaging technique, researchers discovered that our ...
Dec. 2, 2025 Dolichospermum, a type of cyanobacteria thriving in Lake Erie’s warming waters, has been identified as the surprising culprit behind the lake’s dangerous saxitoxins—some of the most potent natural neurotoxins known. Using advanced genome ...
Nov. 28, 2025 Data from over 47,000 dogs reveal that CBD is most often used in older pets with chronic health issues. Long-term CBD use was linked to reduced aggression, though other anxious behaviors didn’t improve. The trend was strongest among dogs whose ...
Nov. 28, 2025 Researchers discovered why bird flu can survive temperatures that stop human flu in its tracks. A key gene, PB1, gives avian viruses the ability to replicate even at fever-level heat. Mice experiments confirmed that fever cripples human-origin flu ...
Nov. 27, 2025 University of Queensland researchers visualized yellow fever virus particles at near-atomic detail, uncovering major structural differences between vaccine and virulent strains. The insights could lead to better vaccines and treatments for yellow ...
Nov. 27, 2025 A photosynthetic bacterium shows a surprising ability to absorb persistent PFAS chemicals, offering a glimpse into biological tools that might one day tackle toxic contamination. Researchers are now exploring genetic and synthetic biology approaches ...
Nov. 26, 2025 Beneath the waters off Papua New Guinea lies an extraordinary deep-sea environment where scorching hydrothermal vents and cool methane seeps coexist side by side — a pairing never before seen. This unusual chemistry fuels a vibrant oasis teeming ...
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Dec. 9, 2025 Ancient pterosaurs may have taken to the skies far earlier and more explosively than birds, evolving flight at their very origin despite having relatively small brains. Using advanced CT imaging, ...
Dec. 9, 2025 Scientists have confirmed that Nanotyrannus was a mature species, not a young T. rex. A microscopic look at its hyoid bone provided the key evidence, matching growth signals seen in known T. rex ...
Dec. 8, 2025 High-resolution imaging has revealed the internal layout of chromatin condensates, showing how DNA fibers fold and interact within these droplet-like structures. The findings connect molecular ...
Dec. 6, 2025 Scientists have discovered that complex life began evolving much earlier than traditional models suggested. Using an expanded molecular clock approach, the team showed that crucial cellular features ...
Dec. 5, 2025 Researchers have uncovered a new species of wolf snake on Great Nicobar Island and named it Lycodon irwini in tribute to Steve Irwin. The glossy black, non-venomous snake grows up to a meter and ...
Dec. 4, 2025 Experiments reveal that pond frogs can eat highly venomous hornets without suffering noticeable damage, even after repeated stings. Most frogs successfully consumed hornets, including the notorious ...
Dec. 4, 2025 Scientists have discovered a strange tubular structure inside Profftella, a symbiotic bacterium in the Asian citrus psyllid. These long, helical tubes, filled with ribosomes, show a complexity not ...
Dec. 3, 2025 Ancient anaconda fossils show that the snakes became giants soon after emerging in Miocene South America. Their size has stayed stable for over 12 million years, even though other huge reptiles went ...
Dec. 3, 2025 Researchers recreated conditions from billions of years ago and found that Earth’s young atmosphere could make key molecules linked to life. These sulfur-rich compounds, including certain amino ...
Dec. 3, 2025 Ant pupae that are fatally sick don’t hide their condition; instead, they release a special scent that warns the rest of the colony. This signal prompts worker ants to open the pupae’s cocoons ...