Science Summary Year 9 Quiz

The given answer accurately defines chromosomes as a gel-like substance where genetic material is found for the cell. Chromosomes are structures within cells that contain DNA, which carries the genetic information necessary for the functioning and development of an organism. They are made up of DNA molecules tightly coiled around proteins, giving them a gel-like appearance. This definition aligns with the known characteristics and functions of chromosomes, making it the correct answer.

Chloroplasts are organelles found in plant cells that are responsible for conducting photosynthesis. Photosynthesis is the process by which plants convert sunlight into energy, using chlorophyll in the chloroplasts to capture light energy and convert it into chemical energy in the form of glucose. This process is essential for the survival of plants as it provides them with the energy they need to grow and carry out their metabolic functions. Therefore, the statement "They conduct photosynthesis" accurately describes the function of chloroplasts.

The function of the cell wall is to provide a strong reinforcing mesh that gives the plant cell its shape. The cell wall is made up of cellulose and other structural components, and it provides support and protection to the cell. It helps maintain the shape of the plant cell, preventing it from collapsing under its own weight. Additionally, the cell wall also acts as a barrier, controlling the movement of substances in and out of the cell.

Chromosomes serve the purpose of carrying genetic instructions. They are found in the nucleus of the cell and contain DNA, which carries the genetic information necessary for the development and functioning of an organism. Chromosomes play a crucial role in passing on traits from one generation to another through the process of cell division and reproduction. They are responsible for determining various characteristics and traits of an individual, such as physical features, behavior, and susceptibility to certain diseases.

Chromosomes are found in the nucleus of a cell. They are thread-like structures made up of DNA and proteins. Chromosomes contain the genetic information necessary for the development and functioning of an organism. They play a crucial role in cell division, as they replicate and separate during the process. Chromosomes carry genes, which are the instructions for making proteins and determining an organism's traits. Therefore, chromosomes are a key component of the nucleus and are responsible for transmitting genetic information from one generation to the next.

The purpose of a vacuole in a plant cell is to store food or any variety of nutrients that the cell might need to survive. Vacuoles are membrane-bound organelles that can occupy a significant portion of the cell's volume. They can store water, ions, sugars, pigments, and other essential molecules. This stored food and nutrients can be used by the cell for energy, growth, and various metabolic processes.

A healthy human cell should have 46 chromosomes. Chromosomes are thread-like structures that contain DNA and carry genetic information. In humans, chromosomes come in pairs, with each pair consisting of one chromosome inherited from the mother and one from the father. Therefore, there are a total of 23 pairs, or 46 chromosomes, in a healthy human cell.

Mitochondria, often referred to as the “powerhouses” of the cell, are responsible for producing adenosine triphosphate (ATP), the cell’s main energy source. This is achieved through a process called cellular respiration, where glucose and oxygen are converted into ATP, carbon dioxide, and water. The ATP produced is then used to power various cellular activities. So, mitochondria essentially generate and supply energy for the cell.

The correct answer is "Cell Wall, Chloroplasts and Vacuole." The animal cell does not have a cell wall, which is a rigid outer layer found in plant cells. Additionally, animal cells do not have chloroplasts, which are responsible for photosynthesis in plant cells. Lastly, animal cells have smaller vacuoles compared to plant cells, which have large central vacuoles.

The plasma membrane is responsible for controlling what substances can enter or exit the cell. It acts as a selective barrier, allowing certain molecules to pass through while preventing others from entering or leaving the cell. This regulation is crucial for maintaining the internal environment of the cell and ensuring that it functions properly. The other options mentioned, such as storing food, controlling the destination of food, being a gel-like substance for chemical reactions, and containing chromosomes, are not accurate functions of the plasma membrane.