ovum

Zygote

...t not always) a sperm cell from a male and an ovum from a female —merge into a single diploid cell called the zygote . Animal zygotes undergo mitotic cell divisions to become an embryo . Other organisms may undergo meiotic cell division at this time (for more information refer to ...

Spermatogenesis

...a human being. (The other half will come from the ovum at fertilisation). The spermatids at this point are still round cells. During the process called spermiogenesis the sperm extrude tails, repackage DNA into a head, cap the head with a lysosome-like acrosome and construct an energy transducing n...

Sperm

...deposited in the vagina - and then it moves to the ovum inside the ovary. See also sperm competition External link The Handbook of Andrology...

Ploidy

...gue, resulting in haploid germ cells ( sperm and ovum ). Diploid Diploid cells (meaning double in Greek ) have two copies ( homologs ) of each chromosome (both sex- and non-sex determining chromosomes), usually one from the mother and one from the father . Most somatic cells (body cells) o...

Gamete

... the species produce the larger gamete called an ovum (or egg) and " males " produce the smaller gamete termed (in animals) a spermatozoon (or sperm). The equivalent "male" structure in higher plants is called a pollen grain . Organs that produce gametes are called gonads in animals , and a...

Embryo

...irst division of the zygote (a fertilized ovum ) until it becomes a foetus . An embryo is called a foetus at a more advanced stage of development and up until birth or hatching. In humans, this is from the eighth week of gestation . Stages : morula -> blastula -> gastrula . ...

Ploidy

...gue, resulting in haploid germ cells ( sperm and ovum ). Diploid Diploid cells (meaning double in Greek ) have two copies ( homologs ) of each chromosome (both sex- and non-sex determining chromosomes), usually one from the mother and one from the father . Most somatic cells (body cells) o...

Cilium

...In the oviducts , the beating of cilia moves the ovum from the ovary to the uterus . Opposite to the motile cilia, non-motile cilium usually exists as one cilium per cell. The outer segment of the rod photoreceptor cell in the human eye is connected to its cell body with a specialized non-motile...

Blastula

...mals . It is produced by cleavage of a fertilized ovum and consisting of a spherical layer of cells surrounding a fluid-filled cavity. The blastula follows the morula and precedes the gastrula in the development sequence. A blastula has around 128 cells, with a large central cavity called the blas...

Acrosome

...ed to penetrate the zona pellucida covering the ovum . Acrosome reaction When the sperm comes in contact with ZP3 in the zona pellucida, this reaction takes place, during which actin polymerizes to form the acrosomal process ; also, the acrosomal vesicle fuses with the plasma membrane of the ...

Acrosome

...ed to penetrate the zona pellucida covering the ovum . Acrosome reaction When the sperm comes in contact with ZP3 in the zona pellucida, this reaction takes place, during which actin polymerizes to form the acrosomal process ; also, the acrosomal vesicle fuses with the plasma membrane of the ...