Answer:
d. mucosa, submucosa, muscularis, serosa
Explanation:
The layers of the digestive tract starting from the lumen are mucosa, submucosa, muscularis and serosa.
- The first layer is mucosa which is made of epithelium cells and helps in absorption of nutrients from digested food. It has numerous villi structure which increase the surface area for absorption.
- Second layer submucosa supports mucosa and is supplied with large blood vessels, nerves and lymphatics. Absorbed nutrients enter the blood vessels which are present in submucosa.
- The third layer muscularis functions to create peristaltic movements in GI tract. Muscles in this layer make the food move and mix with digestive juices.
- Final layer serosa works to reduce friction between digestive tract muscles. It has a thin cell layer which secretes serous fluid that acts as a lubricant.
Answer:
mature egg
Explanation:
Ovulation is an event that occurs during the menstrual cycle of the female under the influence of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Ovarian follicles rupture and release the secondary oocyte ovarian cells from a vesicular follicle. After the release of an egg, it can be fertilized by the sperm during fertilization.
If the scientist excavate two fossils at the grand canyon, the fossil that was found much deeper layer is older.
<h3>What is fossil fuels?</h3>
A fossil fuel is hydrogen- containing material found naturally in the earth's crust from the remain of dead plants and animals that is extracted and burned as a fuel.
Fossil are natural source of energy, it is made from decomposition of plants and animals. Fossil fuels are found in earth's crust and contains carbon and hydrogen which could gives energy by burning.
Coal, oil and natural gas are best examples of fossil fuels. Coal is a material usually found in sedimentary rock deposits where rock and plants are buried from long time.
Natural gas usually found in pockets above oil deposits. It is also found where natural oil is found.
Therefore, the scientist excavate two fossils at the grand canyon, the fossil that was found much deeper layer is older.
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