<span>Endocrine glands can be found in A. all vertebrates. Vertebrates include all animals (with a spine) that exist on our planet, as well as some types of fish. Endocrine glands secrete various hormones inside the body itself, as opposed to the exocrine system. Some endocrine glands are ovaries, testes, pituitary gland, etc.</span>
Sound waves reflecting off of objects
That is correct. Any animal that produces milk is a mammal. That is the key characteristic that defines Class Mammalia.
Producers
To understand food chains and food webs, we must start with where the energy begins. Sunlight is energy, and plants use this energy to turn water and carbon dioxide into plant food. This process is called “photosynthesis”. Plants also need minerals and nutrients. They get these from the soil when their roots take up water. While this might not sound like the kind of food you would want to eat, this plant food allows plants to grow, flower, and produceproduce things like acorns, potatoes, carrots, apples, pecans, and many other kinds of fruits.
Because plants make so much energy, they are called “producers”. Their ability to use sunlight to make food makes them a very important source of energy for other living things. Think about all the animals that eat plants. Wow, it's mind-boggling! Now, think about all the places that plants grow. From the oceans to the deserts to the mountaintops, plants can be found nearly everywhere basking in the sunlight and making their own food. And wherever plants grow, animals that depend upon them are sure to be found.
