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The arithmetic of human sperm A young, healthy man produces about 1000 sperms every second, which comes to about 90 million per day [1]. These sperms are stored in the epididymis and ductus deferens until ejaculation. With several days of storage, the number can easily become big enough to allow for multiple ejaculations on the same day. The maturation ...


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The third photo gets to the heart of the matter. Here's an enlargement: The gold-colored areas are the anthers of some of the stamens, the filaments of which are fused with the tissue of the petal. (This is typical of the Apocynaceae, the family to which A. blanchetti belongs; they have epipetalous stamens, that is the stamens are "adnate" i.e. ...


3

Instinct What is instinct, instinct is any behavior which did not require cognition or consciousness to perform or innate behavior that does not require learning. BY the nature of building a brain it is possible to build in behavior by laying out neurons and connections in preset patterns. Thus some behavior can be encoded genetically. Simple examples of ...


1

Firstly, those aren't bumblebee faces ... those are big fly eyes. Those are Bumblebee Hover Flies (Volucella bombylans): The noise in the first part of the video is identical to a fly flying around your head and the noise at the end sounds like what a fly would sound like when you press it against a surface like a wall or screen (or a newspaper, apparently)


1

I may have misunderstood your question, but there is no theory why usually reproductive costs are on the female, as this is a fact. Females have usually larger (and fewer) reproductive cells (gametes), they frequently have to carry the embryo until birth, and sometimes they have to attend to the offspring during the first stages of their lives. To put it ...


1

The Greenland shark (Somniosus microcephalus) has been reported to need at least 156 ± 22 years reach to sexual maturity1. This is also thought to be the vertebrate with the longest lifespan. Reference 1: Nielsen, J., Hedeholm, R. B., Heinemeier, J., Bushnell, P. G., Christiansen, J. S., Olsen, J., ... & Steffensen, J. F. (2016). Eye lens radiocarbon ...


1

This article provides general facts about Tuataras, one of which is: Tuataras reproduce slowly. They take 10-20 years to reach sexual maturity. Males can mate every year, but females breed every two to five years. It takes the female between one and three years to provide eggs with yolk, and up to seven months to form the shell. Then it takes an additional ...


1

Well, strictly speaking from an etymological viewpoint, a clutch is: "a brood, the number of eggs incubated at any one time," in reference to chickens, 1721, a southern England dialectal variant of cletch (1690s), noun from cleck (v.), which is from Middle English clekken "to hatch, give birth to" (c. 1400), which is probably from a Scandinavian source (...


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