7th Grade Science- Cell Review Quiz

Explanation
The statement that all animal and plant cells are the same is false. Animal and plant cells have some similarities, such as having a nucleus and other organelles, but they also have significant differences. Plant cells have a cell wall, chloroplasts for photosynthesis, and a large central vacuole, which are not present in animal cells. Additionally, animal cells can move independently, while plant cells are generally fixed in place. Therefore, it is incorrect to say that all animal and plant cells are the same.

Explanation
Animal cells have a nucleus and cytoplasm. The nucleus is the control center of the cell, containing the genetic material and regulating cell activities. The cytoplasm is the gel-like substance that fills the cell and contains various organelles, such as mitochondria and ribosomes, which are involved in cellular processes. Vacuoles and chloroplasts are not present in animal cells. Vacuoles are more commonly found in plant cells and serve functions such as storage and maintaining cell shape. Chloroplasts, on the other hand, are specific to plant cells and are responsible for photosynthesis. Therefore, the correct answer is a nucleus and cytoplasm.

Explanation
Schleiden, Schwann, and Virchow's discoveries collectively established the fundamental principles of cell theory. They found that all living things are made of cells, meaning that cells are the building blocks of life. Additionally, they observed that all cells have to come from other cells, suggesting that cells have a reproductive process. Lastly, they concluded that cells are the basic units of structure and function of living things, highlighting the importance of cells in the functioning of organisms. Therefore, the correct answer is that all of these statements are true based on their discoveries.

Explanation
The endoplasmic reticulum is responsible for moving proteins within the cell. It is a network of membranes that extends throughout the cytoplasm, and it plays a crucial role in protein synthesis and transport. Proteins are synthesized by ribosomes attached to the rough endoplasmic reticulum, and then they are transported through the network to their final destinations within the cell or outside of it. Therefore, the endoplasmic reticulum moves proteins to ensure proper distribution and function within the cell.

Explanation
An organelle is a part of a cell that has a specific function or job. Organelles are like specialized compartments within a cell that carry out specific tasks necessary for the cell's survival and functioning. Each organelle has its own unique structure and function, such as the nucleus which contains the cell's DNA, the mitochondria which generate energy, or the endoplasmic reticulum which is involved in protein synthesis. Therefore, an organelle is not just any random part of a cell, but a specialized component that performs a specific role to ensure the cell's proper functioning.

Explanation
The endoplasmic reticulum is a network of membranes within cells that is involved in various cellular processes, including protein synthesis and folding. It contains specialized regions called the rough endoplasmic reticulum (RER), which is studded with ribosomes and is responsible for protein synthesis. During protein synthesis, the RER assists in the folding of newly synthesized proteins into their functional 3D structures. This process is crucial for the proper functioning of proteins within the cell. Therefore, the statement that the endoplasmic reticulum is responsible for protein folding is true.

Explanation
Chromosomes are indeed thread-like structures that are found inside the nucleus of animal and plant cells. They contain the genetic material of an organism and play a crucial role in the transmission of traits from one generation to the next. Therefore, the statement "Chromosomes are thread-like structures located inside the nucleus of animal and plant cells" is correct.

Explanation
The nucleus is often referred to as the "brain" of the cell because it contains the cell's genetic material, DNA, and controls the cell's activities. It regulates the cell's growth, metabolism, and reproduction by directing the synthesis of proteins and other important molecules. Additionally, the nucleus acts as a storage site for genetic information and plays a crucial role in cell division.

Explanation
The cell wall gives plant cells a rigid structure. It is a tough and rigid layer that surrounds the cell membrane, providing support and protection to the cell. The cell wall is made up of cellulose, a complex carbohydrate that gives it strength. It helps maintain the shape of the cell and prevents it from bursting or collapsing under pressure. Unlike animal cells, plant cells have a cell wall, which is a defining feature of plant cells.

Explanation
Mitochondria break down food to release energy through a process called cellular respiration. They are known as the powerhouse of the cell because they produce the majority of the cell's energy in the form of ATP (adenosine triphosphate). This process involves breaking down glucose and other molecules to generate ATP, which is used by the cell for various functions. Therefore, mitochondria play a crucial role in providing energy for cellular activities.