Cell membranes are said to be selectively permeable. Which statement best explains what selectively

2 answers:

6 0

In school I learned 2 as the correct answer. The cell membrane chooses which substances to allow in and out of cell - is what my teacher's definition was.

Ymorist [56]2 years ago

6 0

The correct answer is option 2, that is, the cell membrane lets certain substances enter the cell and keeps certain substances out of the cell.

All the cells are surrounded by a cell membrane. The cells membrane is selectively permeable, that is, it allows only some of the ions or molecules to pass through them by assistance of active or passive transport. For example, the molecules of water can passes passively through small pores on the membrane.

You might be interested in

Why is it critical that equal amounts of DNA are shared between homologous chromosomes?

harina [27]

Homologous chromosomes are chromosomes of equal length, size, and of corresponding genetic material. If, during meiosis, these chromosomes divide improperly, when they are re-combined with the opposite sex's portion, they will combine improperly. The unequal distribution of genetic material in reproduction will eventually create what's call an aneuploid germ cell: this germ cell results in dead zygotes, which leads to a miscarriage or spontaneous abortion in about 25 percent of all conceptions. So we see that it is imperative the genetic material of these chromosomes be exactly where it is supposed to be: so that it can combine perfectly with its compliment.

6 0

2 years ago

RNAi is a technique that silences genes by targeting them and degrading their mRNA. How can this technique be used in scientific

Anestetic [448]

For the first one I’d say D

The answer for the 2nd one is C.

4 0

3 years ago

Read 2 more answers

Breathing involves the movement of diaphragm and Rib cage true or false

Elza [17]

Answer:

Explanation:

It's a true statement as,

When we inhale the diaphragm moves downwards and the rib cage moves upwards and outwards to let enter the outside air containing oxygen come in.
While we exhale the diaphragm comes to its position and the rib cage move downwards and inwards to let out the inside carbon-dioxide and other games out.

Hence, we can conclude that breathing involves the movement of diaphragm and Rib cage.

4 0

2 years ago

What is a scotobacteria

KatRina [158]

Commonly called the enterics due to the fact that they inhabit the intestinal tracts of humans and other animals.

6 0

2 years ago

Read 2 more answers

What are the uses of cholesterol in animals and their cells?

Elan Coil [88]

Answer:

Cholesterol is a structural component of the cell membranes of animals. Because of cholesterol that provides cell membrane structural integrity and fluidity, animal cells need not to have cell walls such as that in bacterial and plant cells.Cholesterol reduces permeability of lipid membranes. ... Cholesterol plays has a role in membrane fluidity but it's most important function is in reducing the permeability of the cell membrane. Cholesterol helps to restrict the passage of molecules by increasing the packing of phospholipids.

Explanation:

5 0

2 years ago