Search results
Results from the WOW.Com Content Network
An antheridium is a haploid structure or organ producing and containing male gametes (called antherozoids or sperm). The plural form is antheridia, and a structure containing one or more antheridia is called an androecium. [1] Androecium is also the collective term for the stamens of flowering plants.
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 with 46 paired chromosomes. In mammals, sperm is stored in the epididymis and released through the penis in semen during ejaculation. The word sperm is derived from the Greek word σπέρμα, sperma, meaning "seed".
The gametophyte is the multicellular structure (plant) that is haploid, containing a single set of chromosomes in each cell. The gametophyte produces male or female gametes (or both), by a process of cell division, called mitosis. In vascular plants with separate gametophytes, female gametophytes are known as mega gametophytes (mega=large, they ...
one of the main sexual systems in bryophytes. [17] In monoicy male and female sex organs are present in the same gametophyte. [18] Monoecy: a sexual system in which male and female flowers are present on the same plant. It is common in angiosperms, [25] and occurs in 10% of all plant species. [26] [dubious – discuss] Sequential hermaphroditism
A sex organ, also known as a reproductive organ, is a part of an organism that is involved in sexual reproduction. Sex organs constitute the primary sex characteristics of an organism. Sex organs are responsible for producing and transporting gametes , as well as facilitating fertilization and supporting the development and birth of offspring.
Or, with bisexual and at least one of male and female flowers on the same plant. [2] Protandrous: (of dichogamous plants) having male parts of flowers developed before female parts, e.g. having flowers that function first as male and then change to female or producing pollen before the stigmas of the same plant are receptive. [6]
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete (haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes . [1]
However, it is a myth that sheep cannot lamb without human assistance; many ewes give birth directly in pasture without aid. [8] Balancing ease of lambing with high productivity is one of the dilemmas of sheep breeding. [7] While the majority of births are relatively normal and do not require intervention, many complications may arise.