Cellular Transport, Respiration, And Reproduction Quiz

Animal cells do not have cell walls and chloroplasts, but plant cells do. The cell wall is a rigid outer layer that provides support and protection to plant cells, while chloroplasts are organelles responsible for photosynthesis, which allows plants to convert sunlight into energy. Animal cells do not require a cell wall as they have a flexible cell membrane that provides support and protection. Additionally, animal cells do not possess chloroplasts as they obtain energy through other means, such as cellular respiration in mitochondria.

Mitochondria and chloroplasts are organelles found in eukaryotic cells. Mitochondria are responsible for producing energy in the form of ATP through cellular respiration, while chloroplasts are involved in photosynthesis, converting light energy into chemical energy in the form of glucose. Therefore, both organelles play a crucial role in providing cells with energy.

The cell membrane serves as the boundary between the cell and its environment. It is a thin, flexible barrier that surrounds the cell and controls the movement of substances in and out of the cell. It is made up of a lipid bilayer with embedded proteins that allow for selective permeability, regulating the entry and exit of molecules. The cell membrane plays a crucial role in maintaining the cell's internal environment and protecting it from external factors.

Active transport is the process of moving molecules or ions across a cell membrane against their concentration gradient, from an area of lower concentration to an area of higher concentration. This process requires the input of energy from the cell in the form of ATP (adenosine triphosphate). Unlike diffusion, osmosis, and facilitated diffusion, which do not require energy input, active transport allows the cell to maintain specific concentrations of molecules or ions inside and outside the cell, enabling it to perform vital functions such as nutrient uptake and waste removal.

The nucleus has multiple functions within a cell. It stores the DNA, which contains the genetic information needed for the cell's functioning. It also controls most of the cell processes by regulating gene expression and protein synthesis. Additionally, the nucleus contains the information needed to make proteins through the process of transcription and translation. Therefore, the correct answer is "all of the above" as all these functions are performed by the nucleus.

Ribosomes are the structures that make proteins using coded instructions that come from the nucleus. They are responsible for protein synthesis in the cell. The nucleus contains the DNA, which contains the instructions for building proteins. These instructions are transcribed into mRNA, which then travels to the ribosomes. The ribosomes read the mRNA and assemble the amino acids in the correct order to form a protein. Therefore, the ribosome is the correct answer for this question.

Passive transport refers to the movement of molecules across a cell membrane without the need for energy input. In this case, the starch molecules would move from left to right through passive transport, as it does not require energy. Osmosis, on the other hand, specifically refers to the movement of water molecules across a selectively permeable membrane, and would not be the correct answer for this question.

The cell wall is usually made of tough fibers, unlike the cell membrane. The cell wall is a rigid structure that provides support and protection to the cell. It is found in all organisms and is composed of various materials such as cellulose, chitin, or peptidoglycan. These tough fibers give the cell wall its strength and enable it to withstand mechanical stress and maintain the shape of the cell. In contrast, the cell membrane is a flexible barrier that surrounds the cell and controls the movement of substances in and out of the cell.

Plants are the only organisms among the options that do not have a cell wall. While animals and fungi have cell walls, plants have a cell wall made of cellulose, which provides structural support and protection to plant cells. The cell wall is absent in animals and fungi, as they have different structural components like chitin in fungi and extracellular matrix in animals. Therefore, the correct answer is plants.

The cell wall is a rigid structure that surrounds the cell membrane in plant cells. Its main function is to provide support and protection to the cell, helping it maintain its shape and prevent damage. However, the cell wall does not store DNA. DNA is stored in the nucleus of the cell, which is surrounded by the cell membrane, not the cell wall. Therefore, the statement that the cell wall stores DNA is incorrect.