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Vagusstoff (literally translated from German as "Vagus Substance") refers to the substance released by stimulation of the vagus nerve which causes a reduction in the heart rate. Discovered in 1921 by physiologist Otto Loewi , vagusstoff was the first confirmation of chemical synaptic transmission and the first neurotransmitter ever discovered.
Fever coat is an effect known in domestic cats, where a pregnant female cat has a fever or is stressed, causing her unborn kittens' fur to develop a silver-type color (silver-grey, cream, or reddish) rather than what the kitten's genetics would normally cause. After birth, over some weeks the silver fur is replaced naturally by fur colors ...
Until approximately one year of age, the kitten is undergoing a growth phase where energy requirements are up to 2.5 times higher than maintenance. [33] Pet nutritionists often suggest that a commercial cat food designed specifically for kittens should be offered beginning at four weeks of age. [28]
[36] [page needed] Thus, in this formulation, the principal cost of sex is that males and females must successfully copulate, which almost always involves expending energy to come together through time and space. Asexual organisms need not expend the energy necessary to find a mate.
In the brown alga Fucus, all four egg cells survive oogenesis, which is an exception to the rule that generally only one product of female meiosis survives to maturity. In plants, oogenesis occurs inside the female gametophyte via mitosis. In many plants such as bryophytes, ferns, and gymnosperms, egg cells are formed in archegonia.
The female is not yet sexually receptive; the old corpus luteum degenerates; the uterus and the vagina distend and fill with fluid, become contractile and secrete a sanguinous fluid; the vaginal epithelium proliferates and the vaginal cytology shows a large number of non-cornified nucleated epithelial cells.
The brain of the domesticated cat is about five centimetres (2.0 in) long and weighs 25–30 g (0.88–1.06 oz). [1] [2] If a typical cat is taken to be 60 cm (24 in) long with a weight of 3.3 kg (7.3 lb), then the brain would be at 0.91% [3] of its total body mass, compared to 2.33% [3] of total body mass in the average human.
Eusociality colonies in which only one female (queen) is reproductive and all other are divided into a castes system, all work together in a coordinate system. This system is used in many unrelated animals: ants , bees , and wasps , termites , naked mole-rat , Damaraland mole-rat , Synalpheus regalis shrimp , certain beetles, some gall thrips ...