Answer: polyunsaturated fatty acid residues
Explanation: Unsaturated fatty acids have a lower melting point so arctic animals have these fatty acids in their membranes.
There are three major types of blood vessels: the arteries, which carry the blood away from the heart; thecapillaries, which enable the actual exchange of water and chemicals between the blood and the tissues; and the veins, which carry blood from the capillaries back toward the heart.
Answer:
The peripheral nervous system (PNS) has two components: the somatic nervous system and the autonomic nervous system. The PNS consists of all of the nerves that lie outside the brain and spinal cord
Explanation:
So carbon dioxide can diffuse from the leaf
Answer:
Living things may be distinguished from non-living things in their ability to carry on life processes such as movement, respiration, growth, responsiveness to environmental stimuli and reproduction. This view of living may be appropriate at this age but has some limitations and can lead to the alternative conceptions above. For example movement in plants is not apparent to students and consequently they may not consider plants living.