Common cell structure outer covering called and internal gelatinlike

cell membrane, cytoplasm

Explanation:

The cell membrane is the outer covering that allows food and oxygen into the cell and waste products out of the cell. It is a multifaceted membrane that envelopes a cell's cytoplasm. It protects the integrity of the cell along with supporting the cell and helping to maintain the cell's shape. Proteins and lipids are the major components of the cell membrane. The exact mix or ratio of proteins and lipids can vary depending on the function of a specific cell. Phospholipids are important components of cell membranes. They spontaneously arrange to form a lipid bilayer that is semi-permeable such that only certain substances can diffuse through the membrane to the cell's interior. Similar to the cell membrane, some cell organelles are surrounded by membranes. The nucleus and mitochondria are two examples.

The cytoplasm is a gelatinlike substance inside the cell membrane that supports and suspends organelles and cellular molecules. Many cellular processes also occur in the cytoplasm, such as protein synthesis, the first stage of cellular respiration (known as glycolysis), mitosis, and meiosis. The cytoplasm helps to move materials, such as hormones, around the cell and also dissolves cellular waste.

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.