Sperm

Sperm is the male reproductive cell and is derived from the Greek word (σπέρμα) sperma (meaning "seed"). In the types of sexual reproduction known as anisogamy and its subtype oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell. A uniflagellar sperm cell that is motile is referred to as a spermatozoon, whereas a non-motile sperm cell is referred to as a spermatium. Sperm cells cannot divide and have a limited life span, but after fusion with egg cells during fertilization, a new organism begins developing, starting as a totipotent zygote. The human sperm cell is haploid, so that its 23 chromosomes can join the 23 chromosomes of the female egg to form a diploid cell. In mammals, sperm develops in the testicles and is released from the penis. It is also possible to extract sperm through TESE. Some sperm banks hold up to 170 litres (37 imp gal; 45 US gal) of sperm.

Sperm in animals

Anatomy

The mammalian sperm cell consists of a head, a midpiece and a tail. The head contains the nucleus with densely coiled chromatin fibres, surrounded anteriorly by an acrosome, which contains enzymes used for penetrating the female egg. The midpiece has a central filamentous core with many mitochondria spiralled around it, used for ATP production for the journey through the female cervix, uterus and uterine tubes. The tail or "flagellum" executes the lashing movements that propel the spermatocyte.

Sperm (disambiguation)

Sperm commonly refers to:

Sperm may also refer to:

Sperm (album)

Sperm is the second studio album by the German band Oomph!. This album would drastically change the direction and sound of the band from their heavily synthesizer-based, EBM debut album. The band at this point decided to change to a heavy metal based style while retaining many elements of their EBM origins and influences.

Sperm is widely regarded as the establishing album of the Neue Deutsche Härte genre.

Track listing

New Edition Tracklist

Lionel

Lionel is a given name which may refer to the following:

People

Lionel convention

Lionel is a contract bridge bidding convention used in defense against an opposing 1NT openings. Using Lionel, over a 1NT opening of the opponents:

Any of the overcalls denote high-card strength corresponding to 12+ (or good 11) high card points.

The convention is named after Lionel Wright from New Zealand who published it in the International Popular Bridge Monthly magazine of May 1993.

Responses

Following the Lionel double, the partner of the double responds as follows:

(1NT) - dbl - (pass) - ??

After a minor suit Lionel overcall, the responses are straightforward. For instance:

(1NT) - 2♣ - (pass) - ??

Advantages/disadvantages

Like using Brozel, CoCa or DONT, using Lionel has the consequence of losing the penalty double over opponent's 1NT. Although this is often seen as a loss, Lionel Wright argued that this loss turns into an advantage as it opens the possibility to defend 1NT doubled with split points between you and your partner. As a balanced holding of the majority of points is far more likely to occur than holding the majority of points in an imbalanced way, a conventional non-penalty double over 1NT holds the potential of paying-off on many hands. Also, non-penalty doubles are more difficult to deal with than traditional business doubles.

Lionel (disambiguation)

Lionel is a masculine given name. It may also refer to: