Functions of Cell Membrane The cell membrane provides mechanical support that facilities the shape of the cell while enclosing the cell and its components from the external environment. It regulates what can be allowed to enter and exit the cell through channels, acting as a semi-permeable membrane...
As you know, sperm cells look a bit like tadpoles with long tails, orflagella, which they whip in order to swim to their destination and fertilize an egg cell. The sperm tail is made of tubulin and is an example of a microtubule filament used for cell locomotion. Another well-known moti...
cell- (biology) the basic structural and functional unit of all organisms; they may exist as independent units of life (as in monads) or may form colonies or tissues as in higher plants and animals pronucleus- the nucleus of the ovum or sperm after fertilization but before they fuse to fo...
The acrosome of the sperm head is a giant lysosome that ruptures and releases enzymes on the surface of the egg. This provides the way for sperm entry into the egg by digesting the egg membrane. f. As Janitors of the Cell Lysosomes remove ‘junk’ that may accumulate in the cell helpi...
Angiosperms primarily reproduce sexually through the production and fertilization of sperm and egg cells that produce a seed. The sperm cells reside in the pollen of plants and the egg cell resides in the ovary of the flower.What Is an Angiosperm? Angiosperms are flowering vascular plants and are...
(such as vaginal fluids and sperm). definition – what is hiv? hiv (human immunodeficiency virus) is a virus which targets the immune system of a person. with time, this hiv weakens and eventually damages the immune system of the individual. the body starts to lose the ability to defend ...
The beginnings of cell theory Science is not a solitary endeavor, and many important “Aha!” moments have been the result of being in the right place at the right time. Such was the case with the development of cell theory. During a dinner conversation in 1838, German botanist Matthias Ja...
Another word or name for an ovum is egg or egg cell. It is produced by the female reproductive system. What is the main role of an ovum? The main role of the ovum is to provide half of the genetic material or DNA for an embryo as the ovum becomes fertilized by a sperm during sexu...
The genes for the 52 different ribosomal proteins together with those for the three RNAs constitute about 5% of the genome of the bacterial cell. All the ribosomal proteins have been isolated and characterized, and nearly all have been fully sequenced. The small subunit proteins ...
This type of leaf base completely encloses the stem, e.g., Sonchus (Fig. 4.2-1) Polygonum etc. 3. Decurrent Leaf Base: ADVERTISEMENTS: In some plants petiole and leaf base, both become broad, Hat and winged. These ensheath the upper part of node, e.g., Symphytum (Fig. 4.2.-G) ...