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An endosperm is formed after the two sperm nuclei inside a pollen grain reach the interior of a female gametophyte or megagametophyte, also called the embryonic sac.One sperm nucleus fertilizes the egg cell, forming a zygote, while the other sperm nucleus usually fuses with the binucleate central cell, forming a primary endosperm cell (its nucleus is often called the triple fusion nucleus).
This tissue system is present between the dermal tissue and forms the main bulk of the plant body. Parenchyma cells have thin primary walls and usually remain alive after they become mature. Parenchyma forms the "filler" tissue in the soft parts of plants, and is usually present in cortex, pericycle, pith, and medullary rays in primary stem and ...
Vascular tissue – The primary components of vascular tissue are the xylem and phloem. These transport fluids and nutrients internally. Ground tissue – Ground tissue is less differentiated than other tissues. Ground tissue manufactures nutrients by photosynthesis and stores reserve nutrients. Plant tissues can also be divided differently ...
Ground substance is an amorphous gel-like substance in the extracellular space of animals that contains all components of the extracellular matrix (ECM) except for fibrous materials such as collagen and elastin. [1] Ground substance is active in the development, movement, and proliferation of tissues, as well as their metabolism.
It is commonly stated that hair grows about 1 cm per month on average; however reality is more complex, since not all hair grows at once. Scalp hair was reported to grow between 0.6 cm and 3.36 cm per month. The growth rate of scalp hair somewhat depends on age (hair tends to grow more slowly with age), sex, and ethnicity. [3] Thicker hair (>60 ...
Meat is part of the human diet in most cultures, where it often has symbolic meaning and important social functions. [159] Some people choose not to eat meat (vegetarianism) or any food made from animals . The reasons for not eating all or some meat may include ethical objections to killing animals for food, health concerns, environmental ...
Global average human diet and protein composition and usage of crop-based products [11] (more statistics) Humans eat thousands of plant species; there may be as many as 75,000 edible species of angiosperms, of which perhaps 7,000 are often eaten. [12] Most human plant-based food calories come from maize, rice, and wheat. [13]
Mesenchyme is characterized morphologically by a prominent ground substance matrix containing a loose aggregate of reticular fibers and unspecialized mesenchymal stem cells. [5] Mesenchymal cells can migrate easily (in contrast to epithelial cells , which lack mobility, are organized into closely adherent sheets, and are polarized in an apical ...