Answer:
<u>Luteinizing hormone </u>(LH) stimulates Leydig cells to secrete testosterone
<u>Follicle stimulating hormone (FSH)</u> stimulates Sertoli cells to secrete protein and other molecules required for spermatogenesis
Explanation:
Under the influence of gonadotropin-releasing hormone, the anterior pituitary releases luteinizing hormone (LH) and follicle-stimulating hormone (FSH). In males, LH stimulates interstitial cells of testes (Leydig cell) to secrete the hormone testosterone. FSH acts indirectly to stimulate spermatogenesis by causing the release of androgen-binding protein (ABP) from the Sertoli cells. The function of ABP is to maintain the higher concentrations of testosterone to stimulate the final steps of spermatogenesis in the seminiferous tubules.
Answer:
About composition of water and organisms that lives there.
Explanation:
scientists might be able to learn about the composition of seawater that was present millions of years ago if we study those stones that comes in contact to that ancient seawater because the traces of particles still present on it. This study provides valuable information about ancient times of earth and its natural resources. These rocks also provides animals that were present in that sea water at that time.
Answer:
Characteristics of epithelium tissue
1.Polarity- Epithelium is arranged so there is one free surface (apical surface) and one attached surface (basal surface)
2.Cellular nature– Cells in epithelium fit closely together side by side and sometimes atop each other to form sheets of cells. These sheets are held together by specialized junctions.
3.Supported by connective tissue– Attachment to a layer of connective tissue at the basal surface forms a layer called the basement membrane, an adhesive layer formed by secretions from the epithelial cells and the connective tissue cells.
4.Avascular– Epithelium typically lacks its own blood supply.
5.Regeneration– Epithelium cells can regenerate if proper nourished.
6.Absence of nerves (except for a few axons in the deeper layers)
Classification scheme of epithelial tissue:
Typically epithelial tissue is classified on the basis of arrangement and shape of cells. For naming the tissue types, the arrangement of the cells is stated first, then the shape, and is followed by “epithelium” to complete the naming. For example; Simple Squamous Epithelium.
Explanation:
Answer :There was enough oxygen in the atmosphere to support a major burst of life on Earth
Explanation:
The Great Oxygen Event marks the time, approximately 2.5 billion years ago, when there was enough oxygen in the atmosphere to support a major burst of life on Earth
For the first half of the Earht's history, there was no oxygen in the atmosphere. It was inhabited only by single-celled organisms.Of those simple life forms, the cyanobacteria may have. evolved a way to take energy from sunlight, and used it to make sugars out of water and carbon dioxide. They used the same chemical process we know as photosynthesis. This released vast quantities of oxygen into the atmosphere and triggered the evolution of complex life.
