Respuesta :
Animal cells do not have cell walls because they do not need them. Cell walls, which are found in plant cells, maintain cell shape, almost as if each cell has its own exoskeleton. Animals do have a cell membrane though.
What are cell walls?
A rigid layer of nonliving material that surrounds the cells of plants and some other organisms. A cell wall is made up of cellulose, pectin, glycoproteins, hemicellulose and lignin. It is the outer boundary of the cell, it encloses the cytoplasm and the organelles of the cells. In plants cells it is inside the cell wall.
Let's take a look at the options:
- The first one is a tree. A tree is a type of plant and all plants have cell walls and it provides turbidity and durability for the plant. Therefore, a tree has a cell wall eliminating it as a option.
- The second one is fungi. Fungi are a eukaryotic organism that is usually filamentous (forming a mycelium) and heterotrophic. Fungi have a cell wall made of chitin, a nitrogen containing polysaccharide (NO amino acids) called hyphae. Therefore, fungi have a cell wall eliminating it as a option.
- The third one is plants. As mentioned before, all plants have cell walls. But to explain more, plant cells are surrounded by a strong cell wall that can change as they grow. It is made of a mixture of polysaccharides cross-linked together, which can give properties like flexibility, strength, turgor and waterproofing. Therefore, plants have a cell wall eliminating it as a option.
- The last one is animals. Animal cells have a cell membrane instead of rigid walls like plant cells do and that is mainly so they can move. Rigid cell walls don’t move - plants don’t move very much and what movement they do have is very slow and gradual. Animals move constantly - skin has to stretch, muscles must contract and extend. So the cells have to allow for that, and the flexible cell membrane is how they do it. Therefore, the answer is option D.
To learn more about cell functions, check out these links:
- https://brainly.com/question/2622341
- https://brainly.com/question/13075634
- https://brainly.com/question/16830473
- https://brainly.com/question/71938
https://brainly.com/question/1908192
