Stimuli are anything that causes arousal or enables an object to respond or react.
There are many different kinds of stimuli for which is different for every organism, for example, water, light and carbon dioxide are three stimuli and materials needed for photosynthesis in plants to manifest.
In humans, we have nutrients or food, oxygen and water for us to survive. These are stimuli, eyes need light as a stimuli for it see and function. Nasal receptors needs smell as stimuli caused by molecular reactions of an object as a stimuli. And others.
Geologists classify crystals into six groups based on the number of axes and the angles of the facets, or faces, on a specimen. The science of crystallography labels the six categories as isometric, tetragonal, orthorhombic, monoclinic, triclinic and hexagonal.
Osmosis occurs through water channel proteins called aquaporins.
Answer:
a) to provide NADPH for reductive biosynthesis and for dealing with oxidative stress
d) to provide ribose-phosphate for nucleotide and nucleic acid biosynthesis
Explanation:
During the pentose phosphate pathway, glucose 6-phosphate is oxidized into pentose phosphates. This pathway uses NADP as an electron acceptor and reduces it into NADPH. The products of this pathway, the pentose phosphates are used by the cells to synthesize nucleic acids (DNA and RNA). The pentose phosphates are also used for the synthesis of nucleotides and coenzymes such as NADH, FADH2, etc.
These synthetic pathways are particularly occurring at a higher rate in the rapidly dividing cells such as the cells of bone marrow, skin. The NADPH formed during this pathway is used by cells as an electron donor for the reactions of reductive biosynthesis. Some of these pathways are the synthesis of fatty acids, cholesterol and steroid hormones. NADPH is also involved in scavenging reactive oxygen species such as oxygen radicals. These ROS are responsible for oxidative stress.
Answer:
Homologous chromosomes are two pieces of DNA within a diploid organism which carry the same genes,