新西兰奥克兰大学生物学Essay代写:棕熊的有趣事实

识别棕熊的一种方法是通过肩膀顶部的驼峰。由肌肉制成的驼峰被认为使熊更容易挖掘巢穴。没有其他现存的熊有这种驼峰。成年熊有短尾和锋利的牙齿,弯曲的下犬齿。他们的头骨沉重而凹陷。棕熊的范围包括北美北部和欧亚大陆,包括美国,加拿大,俄罗斯,中国,中亚,斯堪的纳维亚半岛,罗马尼亚,高加索和安纳托利亚。有一段时间,它也遍布整个欧洲,北非,以及北美的墨西哥。棕熊的爪子很大,弯曲,钝。他们的爪比黑熊更直,更长。与容易爬树的黑熊不同,由于其重量和爪状结构,棕熊的爬行频率较低。棕熊的大小变化很大,取决于亚种和食物供应。男性比女性大约30%。平均大小的熊的长度可能在5到8英尺之间,重700磅,然而,更小和更大的标本出现。平均而言,北极熊比棕熊大,但是大灰熊和北极熊相当。您可能会从他们的名字中猜出棕熊是棕色的。然而,这些熊可以是棕色,红色,棕褐色,奶油色,双色或近黑色。有时它们的毛皮尖端是有色的。毛皮长度根据季节而变化。在夏天,他们的皮毛更短。在冬季,一些棕熊的毛皮长度可达4至5英寸。棕熊栖息在各种各样的环境中。它们被记录在海拔到5000米(16000英尺)的海拔高度。他们居住在温度较高的森林中,喜欢半开放的地区,但也生活在苔原,草原和河口。生活在人们附近的熊可能会捕食宠物和牲畜,并清除人类的食物。棕熊在秋季每天吃掉多达90磅的食物,其重量是春季从窝里出来的两倍。成年棕熊面对很少的食肉动物。根据他们居住的地方,他们可能会被老虎或其他熊袭击。棕熊主宰灰狼,美洲狮,黑熊甚至北极熊。大型食草动物很少威胁熊,但可能致命伤害一只自卫或保护小牛。虽然棕熊有着凶猛的食肉动物的美誉,但它们实际上可以从植被中获得高达90%的卡路里。熊是杂食性的,自然好奇吃几乎任何生物。他们喜欢的食物是丰富且容易获得的,根据季节而变化。他们的饮食包括草,浆果,根,腐肉,肉,鱼,昆虫,坚果,花,真菌,苔藓,甚至松果。 新西兰奥克兰大学生物学Essay代写:棕熊的有趣事实 One way to identify a brown bear is by the hump at the top of its shoulder. The hump, which is made of muscle, is believed to make it easier for the bear to dig a den. No other extant species of bear has this hump. Adult bears have short tails and sharp teeth with curved lower canines. Their skulls are heavy and concave. The brown bear's range includes northern North America and Eurasia, including the United States, Canada, Russia, China, Central Asia, Scandinavia, Romania, Caucasus, and Anatolia. At one time, it was also found throughout Europe, in northern Africa, and as far south as Mexico in North America. Brown bears' claws are large, curved, and blunt. Their claws are straighter and longer than those of black bears. Unlike the black bear, which readily climbs trees, the brown bear climbs less frequently due to its weight and claw structure. Brown bear size is highly variable, depending both on subspecies and...
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新西兰奥克兰大学生物学Essay代写:蛇毒如何工作?

蛇毒是毒蛇修饰唾液腺的液体分泌物。 蛇依靠毒液来禁用猎物并帮助消化过程。 蛇毒的主要成分是蛋白质。 这些毒性蛋白是蛇毒大部分有害作用的原因。 它还含有酶,有助于加速破坏大分子之间化学键的化学反应。 这些酶有助于碳水化合物,蛋白质,磷脂和核苷酸在猎物中的分解。 有毒的酶还可以降低血压,破坏红血球,并抑制肌肉控制。 蛇毒的另一个组分是多肽毒素。 多肽是氨基酸链,由50个或更少的氨基酸组成。 多肽毒素破坏导致细胞死亡的细胞功能。 蛇毒的一些有毒成分在所有有毒蛇种中都有发现,而其他成分仅在特定物种中发现。 新西兰奥克兰大学生物学Essay代写:蛇毒如何工作? Snake venom is the fluid secretions from the modified salivary glands of venomous snakes. Snakes rely on venom to disable prey and aid in the digestive process. The primary component of snake venom is protein. These toxic proteins are the cause of most of the harmful effects of snake venom. It also contains enzymes, which help to speed up chemical reactions that break chemical bonds between large molecules. These enzymes aid in the breakdown of carbohydrates, proteins, phospholipids, and nucleotides in prey. Toxic enzymes also function to lower blood pressure, destroy red blood cells, and inhibit muscle control. An additional component of snake venom is polypeptide toxin. Polypeptides are chains of amino acids, consisting of 50 or fewer amino acids. Polypeptide toxins disrupt cell functions leading to cell death. Some toxic components of snake venom are found in all poisonous snake species, while other components are found only in specific...
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