For what percentage of time has life existed on earth round to the nearest whole number

Explain why the growing of willow for biofuel is an example of sustainable development.

Name the substance which accumulates in muscles when respiration occurs within insufficient oxygen

Many cell functions involve communication between cells via molecular signals that must be sent from one cell to be received by a target cell. Suppose the signal to be sent is a small protein. Where would you expect to find the protein in the Golgi?

Which of the following includes the medulla, pons, cerebellum, and reticular formation and governs functions such as balance and coordination, consciousness, and digestion? a. forebrain b. hindbrain c. midbrain d. split-brain

Complete burning of plant material returns carbon primarily to the A. herbivores. B. water. C. vegetation. D. atmosphere.

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.