Cells, Size, and Survival: The Importance of Surface Area and Transport Systems

The video explains that all organisms, regardless of size, are made up of cells. Smaller organisms like bacteria consist of a single cell, while larger organisms like humans are composed of millions of cells. The video discusses the importance of the surface area to volume ratio, using cubes as an analogy, to explain why larger organisms cannot be made of a single giant cell. It highlights that smaller cells have a higher surface area to volume ratio, allowing for more efficient diffusion of oxygen and nutrients. This efficiency is crucial for cell survival and is why larger organisms require a circulatory system to transport nutrients and oxygen to all cells.

What is the primary difference between single-celled and multicellular organisms?

• Single-celled organisms have multiple cells.

• Multicellular organisms do not need a transport system.

• Multicellular organisms are made of a single giant cell.

• Single-celled organisms rely on their cell membrane for material exchange.

Why can't larger organisms be made of a single giant cell?

• Because a single cell would not allow efficient material exchange.

• Because a single cell would have too much surface area.

• Because a single cell cannot support complex life functions.

• Because a single cell cannot divide.

What is the surface area of a cube with sides of 1cm?

• 24cm²

• 12cm²

• 6cm²

• 1cm²

How does the surface area to volume ratio change as a cell gets larger?

• It increases.

• It decreases.

• It remains the same.

• It becomes infinite.

Why is a higher surface area to volume ratio beneficial for cells?

• It allows for faster diffusion of materials.

• It makes the cell more stable.

• It increases the cell's volume.

• It decreases the cell's surface area.

What limits the maximum size of a cell?

• The thickness of its membrane.

• The amount of DNA it contains.

• The surface area to volume ratio.

• The number of organelles it has.

What happens if a large organism is made of a single cell?

• It can survive without oxygen.

• Material exchange would be too slow.

• It would not need a circulatory system.

• It would have a high surface area to volume ratio.

Why do larger organisms need a circulatory system?

• To transport materials directly to cells.

• To decrease their volume.

• To eliminate the need for oxygen.

• To increase their surface area.

What role does the heart play in the circulatory system?

• It produces oxygen.

• It stores nutrients.

• It filters blood.

• It acts as a strong pump.

How does the circulatory system benefit multicellular organisms?

• By eliminating the need for a cell membrane.

• By increasing the organism's surface area.

• By providing a direct supply of nutrients and oxygen to cells.

• By reducing the number of cells.