The outer layer of a human cell allows some substances to pass through but keeps other substances out. what is the name of this layer?

a. cytoskeleton

b. cytoplasm

c. membrane

d. skin

Which phrase describes a characteristic of a scientific law?

Match the following. 1. chromosome The basic building block of all forms of life 2. chloroplast The rigid wall of plant cells that surrounds the cell membrane 3. nucleus The tiny body that contains chlorophyll 4.

Ponds, lakes, streams and rivers are all part of what kind of ecosystems? a. ocean b. marine c. estuaries d. freshwater

During a woman's physical examination, the nurse notes that the lower uterine segment is soft on palpation. the nurse would document this finding as:

When did Charles Darwin begin to formulate his concept of evolution by natural selection?

At which trophic level are dragonflies that consume

Which example is an organism? A. bacteria B. heart C. clay D. soil

What are some examples of a chemical reaction?

If you continue to increase the intensity of light that a plant receives, what happens? A. The rate of photosynthesis increases indefinitely with light intensity. B. The rate of photosynthesis decreases indefinitely with light intensity. C.

Three structural changes that occur in young unmodified plant cells as they develop into xylem tissues