Which of the choices listed below are characteristics shared by all epithelial tissues? 1 contain a high amount of extracellular matrix (substance between cells) 2 avascular (no blood vessels) 3 cells closely joined together 4 form surface layers 5 found immediately next to blood-vessel rich connective tissues?
Epithelial tissues are characterized by being highly cellular with little to no extracellular matrix, avascular, and having cells closely joined together. They are attached to a basal lamina and possess the ability to quickly regenerate cells.
The characteristics shared by all epithelial tissues include cells that are closely joined together, forming an impermeable barrier thanks to tight junctions, the presence of avascularity meaning they contain no blood vessels and rely on diffusion or absorption for nutrient exchange, and the fact that they form surface layers covering body surfaces and lining internal cavities.
Epithelial tissues are also directly positioned next to connective tissues rich in blood vessels. Another key characteristic is that these tissues are highly cellular with little to no extracellular matrix material between cells.
The basal lamina, part of the epithelial tissue, is a thin layer composed of glycoproteins and collagen, and it serves as the attachment site separating the epithelium from the underlying connective tissue. Furthermore, epithelial tissues are known for their ability to rapidly replace damaged and dead cells, an essential feature for maintaining the integrity of surfaces that are frequently exposed to wear and tear, such as in the airways and digestive tracts.
Why do plant cells need chloroplasts? Explain.
Answer:
Plant cells need chloroplast as they are the site for photosynthesis.
Explanation:
The chloroplast is the green-colored double membrane-bound organelles present mostly in cells of leaves of green plants. Chloroplasts have chlorophyll pigments which serve to trap the sunlight for the process of photosynthesis. Both light-dependent and light-independent phases of photosynthesis take place in chloroplast to form organic sugars.
Hence, chloroplasts serve as a site for photosynthesis in plants.
which circumstance can cause negative population growth?
a.) the emigration rate is lower than the birthrate
b.) the immigration rate is the same as the birthrate
c.) the birthrate is higher than the death rate
d.) the death rate is higher than the birthrate
Answer:
D
Explanation:
If more specimens are dying than those being born, then we can assume that there will be a decrease in population.
Answer:
Option D, the death rate is higher than the birthrate
Explanation:
Please see the attachment
What should you do if there is some question about which layer is the organic one during an extraction procedure?
This protein is present at every replication fork and prevents dna polymerase from dissociating, but does not impede the rapid movement of the enzyme.