Online Quiz (7th Grade)

Calcium is a mineral that is essential for strong bones. It plays a crucial role in maintaining bone health and density. Calcium is responsible for the formation and development of bones and teeth, and it also helps in muscle contraction, nerve function, and blood clotting. Adequate calcium intake is necessary to prevent conditions like osteoporosis and ensure optimal bone strength. While other minerals like potassium, iron, and magnesium are also important for overall health, calcium specifically promotes strong bones.

Keratin is a type of protein that is found in the cells of hair. It is responsible for providing strength and structure to the hair strands. This protein is also found in other parts of the body, such as the skin and nails. Therefore, the statement that the protein that fills the cells of your hair is called keratin is true.

Proteins are the nutrients that are primarily responsible for building and repairing the body's cells. They are composed of amino acids, which are the building blocks of protein. Proteins play a crucial role in the growth, development, and maintenance of tissues, organs, and muscles. They are involved in various functions in the body, such as forming enzymes and hormones, transporting molecules, and supporting the immune system. Therefore, proteins are essential for the overall structure and functioning of the body's cells.

Carbohydrates are a group of nutrients that include sugars and starches. They are the body's main source of energy and play a crucial role in maintaining overall health. Carbohydrates are broken down into glucose, which is then used by the body for various functions, including fueling the brain and muscles. They can be found in a wide range of foods, such as fruits, vegetables, grains, and dairy products. Carbohydrates provide essential nutrients and are an important part of a balanced diet.

Iron is the mineral that enables blood to carry oxygen. Iron is an essential component of hemoglobin, a protein in red blood cells that binds to oxygen and transports it throughout the body. Without adequate iron levels, the production of hemoglobin is compromised, leading to a condition called iron deficiency anemia. This can result in fatigue, weakness, and decreased oxygen delivery to tissues. Therefore, iron is crucial for the proper functioning of the circulatory system and the transportation of oxygen to various organs and tissues in the body.

Vitamin C is the correct answer because it is known for its ability to boost the immune system and protect against common colds. It is a powerful antioxidant that helps to strengthen the immune system by promoting the production of white blood cells, which are responsible for fighting off infections and viruses. Additionally, vitamin C helps to stimulate the production of antibodies, which are essential for immune response. Therefore, consuming enough vitamin C can help to prevent and reduce the severity of colds and other respiratory infections.

Acne is not a disease in which the sweat glands become infected. It is a skin condition that occurs when hair follicles become clogged with oil and dead skin cells, leading to inflammation and the formation of pimples. The main cause of acne is hormonal changes, not infection of the sweat glands.

Dental caries is the correct answer because it is the most common disease caused by acid attacking the enamel in humans. Dental caries, also known as tooth decay or cavities, occurs when bacteria in the mouth produce acids that erode the enamel, leading to the formation of cavities in the teeth. It is a prevalent oral health issue and can cause pain, tooth loss, and other complications if left untreated. Scurvy is a condition caused by vitamin C deficiency, AIDS is a viral disease, and plaque is a sticky film of bacteria that can contribute to tooth decay but is not the disease itself.

Vitamin A is essential for promoting normal growth as it plays a crucial role in cell division and differentiation. It helps in the development and maintenance of healthy skin, bones, and teeth. Additionally, Vitamin A is important for the proper functioning of the immune system and vision. It also supports the growth and development of various organs and tissues in the body. Therefore, the presence of Vitamin A in the list of vitamins that promote normal growth is justified.

The primary function of the mitochondria in eukaryotic cells is to produce energy through the process of cellular respiration. Mitochondria convert glucose and oxygen into adenosine triphosphate (ATP), the energy currency of the cell, along with carbon dioxide and water as byproducts. This process is essential for powering various cellular activities and maintaining cellular function.