What are abiotic factors? how can they affect the population dynamics? give some examples?

1 answer:

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Abiotic factors are things that aren't living that effect an environment, like pH (how acidic the soil is), the temperature, amount of light, and so on. These can effect a population by making it more difficult to survive, perhaps creating more competition over available resources and so on. So for example, if the soil is really acidic in an area, a population of plants may not be able to grow well in that environment.

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Outermost layer of the cell wall is

(A)Plasmalemma

(B)Secondary wall

(C)Middle lamella

(D)Primary wall

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Hint: The wall which is present at the outermost of the cell wall acts as a glue between the different cells. . The secondary wall is not present in every cell, it is present in few cells that alter the growth of the primary wall.

Complete answer:

A cell wall is an outer structural layer present in only some types of cells, just outside the cell membrane. It is usually tough, flexible, and sometimes rigid. The cell wall is mostly composed of two layers and sometimes three layers too. The layers of the Cell wall are as follows-

- The primary cell wall is generally a flexible thin, and an extensible layer formed while the cell is growing i.e not fully developed. It is usually made up of cellulose and it is often permeable too.

-The middle lamella, a layer rich in pectins. It is the outermost layer that forms the interface between adjacent plant cells and glues them together.

-The secondary cell wall, if present, is a thick layer formed inside the primary cell wall after the cell is mature. it's not found in all cell types.

Additional Information: The cell wall is majorly composed of the cellulose microfibrils that are linked via hemicellulosic tethers to form the cellulose-hemicellulose network, which is embedded in the pectin matrix. The most common hemicellulose present in the primary cell wall is xyloglucan.

The outer part of the primary cell wall of the plant epidermis is mostly covered with the cutin and wax, forming a permeability barrier known as the plant cuticle.

Secondary cell walls contain a wide range of additional compounds that helps to enhance and modify their mechanical properties and permeability. The major polymers that make up wood (largely secondary cell walls) include cellulose, 35-50% .xylan, 20-35%, a type of hemicellulose, and lignin, 10-25%.

8 0

3 years ago

We will spend a little time exploring the city with trolley cars and many hills. Where are we?

Cloud [144]

Exploring the city with trolley cars and many hills. This city is San Francisco, CA.

Trolley cars or cable cars were introduced in 1873 to enable locals to contend with many hills the city is built on. Now, tourists ride the cable cars and will be given a tour of the city.

3 0

3 years ago

Increase in antibiotic resistant bacteria is most likely due to:

melomori [17]

Answer:

c. Evolution

Explanation:

Antibiotics are drugs that fight infections by destroying specific parts of the bacteria that cause them. To survive the attack, some bacteria evolve, adapt and create resistance to medication. Then, this practically immune bacteria to the medicine can spread its "superpower" to the descendants. This is why taking antibiotics without a doctor's request is so dangerous to your health and that of the general population.

3 0

4 years ago

In order for a cell to divide successfully, the cell must first

earnstyle [38]

The cell must Replicate its DNA for the Daughter cell

5 0

4 years ago