Why do ecosystems need a constant input of energy from an external source

What is a mitochondrium?

A father with blood type o and a mother with blood type ab have 2 children. One child has blood type a. What is a possible blood type of the other child?

Between glucose urea k + ATP, which one is permeable

What is the relationship between CO2 and O2 for urchins?

If Oil was spilled in a rainforest ecosystem, what would happen?

I'm writing a 5 para for science ab skin cancer. i have a lot of info but i am having trouble wording it. how should i paraphrase this? "Skin cancer is the uncontrolled growth of abnormal skin cells.

Speciation that results from the formation of a geographic feature that isolates some members of a population from other members is an example of: a. allopatric speciation b. directed speciation c. stabilizing speciation d. sympatric speciation

Vegetative plant organs are the root, stem, and leaf. Each organ has a specific function for the survival of the plant. Which organ is the part of the plant that supports the leaves and flowers?

Which molecule is synthesized by plants and is a major source of energy for plants and animals?

A biology student wants to understand how blood flows through the aorta. To model the heart and aorta, she sets up two identical pressure-controlled tanks that push blood through a 2-centimeter diameter tube. Her results are shown in the table below.