Week One: Health Science

Explanation
The skin is considered an organ because it is a complex structure that performs specific functions in the body. It acts as a protective barrier, regulating body temperature, preventing dehydration, and sensing touch, pressure, and pain. The skin is composed of multiple layers and contains various structures such as hair follicles, sweat glands, and blood vessels. It also plays a role in the immune system by housing immune cells. Therefore, the skin meets the criteria of being an organ, which is a group of tissues working together to perform a specific function.

Explanation
Cells do not need food to live. While organisms made up of cells, such as humans, require food for energy and nutrition, individual cells do not have the same requirement. Cells obtain energy through processes like cellular respiration or photosynthesis, depending on the type of cell. Therefore, the statement that cells need food to live is false.

Explanation
The statement is true because the human body is made up of trillions of cells. Each organ, tissue, and system in the body is composed of cells that perform specific functions. These cells work together to carry out various processes necessary for the body's survival and functioning. Therefore, it can be concluded that people have billions of cells.

Explanation
Tissue is not named after tissue paper. The term "tissue" refers to a group or layer of cells that perform a specific function in an organism. Tissue paper, on the other hand, is a lightweight paper used for various purposes such as cleaning or wrapping. The two terms are unrelated and have different origins.

Explanation
The statement is true because the heart is responsible for pumping blood to all parts of the body. It does this by contracting and relaxing in a rhythmic manner, allowing blood to be pushed out of the heart and circulated through the blood vessels. The blood carries oxygen and nutrients to the organs and tissues, while also removing waste products. Without the heart's pumping action, the body would not receive the necessary oxygen and nutrients for survival.

Explanation
The reproductive system is indeed a system of the human body. It is responsible for the production, development, and delivery of gametes (sperm and eggs) necessary for sexual reproduction. This system includes organs such as the testes, ovaries, uterus, and fallopian tubes, as well as other structures involved in the process of reproduction.

Explanation
A tissue is indeed bigger than an organ. Tissues are groups of similar cells that work together to perform a specific function, while an organ is made up of different tissues that work together to perform a specific function. Since an organ is composed of multiple tissues, it is generally larger in size compared to a single tissue.

Explanation
This statement is incorrect. Cells do not grow from seeds. Cells are the basic building blocks of all living organisms and they divide and multiply to form new cells. Seeds, on the other hand, are structures produced by plants for reproduction. They contain an embryo and are capable of developing into a new plant under suitable conditions. Therefore, cells do not grow from seeds.

Explanation
The nose is indeed an organ used for smelling. It contains olfactory receptors that detect different scents and send signals to the brain, allowing us to perceive and distinguish various odors. Additionally, the nose plays a role in our sense of taste, as the flavors of food are greatly influenced by its aroma.

Explanation
Animals have cells because cells are the basic structural and functional units of all living organisms, including animals. Cells are responsible for carrying out various biological processes, such as metabolism, growth, and reproduction. Animals, being multicellular organisms, are composed of numerous cells that are specialized to perform specific functions. These cells work together to form tissues, organs, and organ systems, enabling animals to carry out complex functions and maintain homeostasis. Therefore, it is true that animals have cells.