Absorption of sunlight in photosystem II is the first step of the light dependent reaction, not the light independent reaction. During the light independent reaction, or the Calvin Cycle, carbon fixation first occurs. CO2 produced during the light dependent reaction reacts with RuBP, ultimately producing PGA. This reaction is catalyzed by the enzyme Rubisco. Then, PGA is converted to G3P, using ATP and NADPH produced during the light dependent reaction. The G3P is ultimately converted to glucose. Every 3 cycles of the Calvin Cycle (light independent reaction), 6 molecules of G3P are produced; only 1 is used to produce glucose. The remaining 5 molecules of G3P are used to regenerate RuBP to allow the Calvin Cycle to continue.

A clade is a group of related species all descending from a common ancestor, including that ancestor. They have at least one shared derived trait unique to the clade and differentiating them from all other clades. Clades can be nested within each other: the mammalian clade is part of the vertebrate clade, which is part of the animal clade.

The law of independent assortment states that inheritance of one gene does not influence inheritance of another gene. Thus, inheritance of seed color does not affect the inheritance of seed shape.

The net production of ATP is 2.

This is because for glycolysis to occur, 2 ATP must be used. Glycolysis goes on to produce 4 ATP. The loss of 2 ATP and the gain of 4 ATP results in a total net gain of 2 ATP molecules. Note that the ATP produced during glycolysis are via substrate level phosphorylation.

Hormones and other signaling molecules generate physiological responses by binding to specific receptor proteins in or on target cells. Only cells that have receptors for the secreted molecule (hormone, neurotransmitter, neurohormone, etc.) are target cells; other cells are nonresponsive.

There are five different classifications for molecular signaling. These are as follow:

Endocrine signaling: Secreted molecules diffuse into the bloodstream and trigger responses in target cells throughout the body.

Paracrine signaling: Signaling molecules diffuse locally and trigger a response in neighboring cells.

Autocrine signaling: Secretion of molecules that diffuse locally and trigger a response on the same cells that secreted them.

Synaptic signaling: Secretion of neurotransmitters that diffuse across synapses and trigger a response in cells or target tissues (neurons, glands, and muscles).

Neuroendocrine signaling: Secretion of hormones from neuronal cells that diffuse into the bloodstream and trigger a response on cells throughout the body.

Human pregnancy can be divided into three trimesters, each categorized by different symptoms and stages of fetal development. During the second trimester of pregnancy, which occurs between 13 and 28 weeks, fetal movement can be felt. This is often called “quickening,” which is the stirring of the fetus.

Punctuated equilibrium is one theory within evolutionary biology that seeks to explain the rate of evolution over time. This theory describes most species being in a state of stasis, with little change occurring. When change does occur, however, it is rapid. The theory of punctuated equilibrium stands in opposition to the theory of gradualism and is supported by the fossil record.

The pyruvate decarboxylation reaction is pyruvate+ CoA-SH+ NAD+ -> NADH+ CO2+ acetyl CoA.

The term “zygote” is sued to describe a fertilized egg. The zygote is diploid and formed by the fusion of the sperm and egg gametes. The developing organism is called the zygote until it is composed of 16 cells during cleavage, when it is called the “morula.”

The menstrual cycle is the process of preparing the human female body for potential pregnancy. The cycle can be divided into two stages—the ovarian cycle and the uterine cycle. The uterine cycle has three phases that are called menstruation, the proliferative phase, and the secretory phase.