There are two sex cells known as gametes. The male sex cell is spermatozoa(sperm), and the female sex
cell is the ova(eggs). When they fuse together, reproduction occurs, and results in a zygote (Augustyn,
2019). The structure of spermatozoa consists of the head, the mid piece, and the tail. The head of the
sperm holds the nucleus, which holds the DNA. Enzymes stored in the head of the sperm, also known as
the Acrosome, make penetrating the Zona Pellucida possible (Augustyn, 2019). Mitochondria, the
organelles that produce energy, fill the mid piece, and known as the powerhouse of cells (Augustyn, 2019).
The tail known as flagellum, propels, which give the sperm its motility and the ability to burrow into the
ova. Spermatozoa are the smallest cells in the body (Augustyn, 2019).
The structure of the ova is usually spherical in shape, enclosed in at least one or more egg envelopes, are
non-motile, and the size ranges from ten microns to a couple of centimeters depending on the animal. The
ova, the female sex cell, is the largest cell in the body. It consists of a nucleus, cytoplasm, the Zona
Pellucida, and the Corona Radiata (Augustyn, 2019). The nucleus encloses the cell plasma also known as
yolk, and holds the nutrients needed for developing the egg. When there is more yolk, also called Ooplasm,
the cytoplasm of the ova consists of lipoproteins, water, pigment granules, and cytoplasmic organelles.
The Ooplasm has a tube-like structure called Microvilli, which help substances enter and exit the ooplasm.
The ova hold the genetic material, which is the set of chromosomes from the female gamete (Augustyn,
2019). When fused together with the sperm cell, it will determine the characteristics that the child will
inherit (Augustyn, 2019). The purpose of the ova is reproduction. When the ovaries release the mature
ovum, it travels into the uterus where the male gamete will then enter the egg and result in fertilization
(Augustyn, 2019).
Fertilization takes place after the egg is expelled from the follicle to the uterus by a process called
ovulation. A critical component of the ova that contributes to its function is the mitochondria. The
mitochondria are what gives the ova the energy needed for the hardening of the Zona Pellucida, called the
cortical reaction (Augustyn, 2019). In sperm cells, the most important components that attribute to its
function are the mid piece that holds the mitochondria that produces the ATP needed to propel the
flagellum (Augustyn, 2019). Without the mitochondria there would not be any energy to get the sperm to
the ova. Also, the flagellum consists of bundles of Microtubules that run the entire length of the tail.
Microtubules are what give the sperm propulsion force to reach the egg. Also, in conjunction with the
beating motion, the sperm can burrow into the egg to achieve fertilization (Augustyn, 2019).
Citations:
Augustyn, A. (2019, September 25). sperm | Definition, Function, Life Cycle, & Facts | Britannica.
Britannica. https://www.britannica.com/science/sperm
(2012, September 17). The Reproductive System: How Gonads Go - Crash Course Biology #34 - Bing video.
Https://www. https://www.youtube.com/watch?v=_7rsH2loIY8