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Ciliate conjugation Animation

By: HWC, Views: 2123

Protozoan conjugation is an unusual form of sexual reproduction Prospective partners join together, usually at the surface of their oral depressions. The cells undergo cytoplasmic fusion. Meiosis II produces four haploid micronuclei. Now the macronucleus of each cell begins to bre...

Red Blood Cells - Erythropoietin (EPO)

By: HWC, Views: 7725

• The endocrine system maintains many body conditions within normal limits with feedback loops. Each endocrine feedback loop maintains homeostasis using the following components: • Stimulus - a change in a body condition. • Production cell - an endocrine cell that produces a hormone aft...

Neurosynapse Animation

By: Administrator, Views: 10699

In the nervous system, a synapse is a structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or to the target effector cell. Synapses are essential to neuronal function: neurons are cells that are specialized to pass signals to individual tar...

Secondary Active Transport

By: HWC, Views: 8273

Energy stored (in a hydrogen or sodium concentration gradient) is used to drive other substances against their own concentration gradients Secondary active transport, is transport of molecules across the cell membrane utilizing energy in other forms than ATP. In many cells, antiporters mov...

Optic Nerve and Optic Disk Animation (Part 2 of 2)

By: Administrator, Views: 10736

The optic disc or optic nerve head is the point of exit for ganglion cell axons leaving the eye. Because there are no rods or cones overlying the optic disc, it corresponds to a small blind spot in each eye. The ganglion cell axons form the optic nerve after they leave the eye. The optic disc ...

Phases of an Action Potential - Resting Potential, Threshold, Rising, Falling, & Recovery Phases

By: HWC, Views: 7153

In this tutorial, we will review the phases of an action potential measured from a small area of a neuron's membrane. The action potential can be divided into five phases: the resting potential, threshold, the rising phase, the falling phase, and the recovery phase. When the neuron is at rest,...

Types of Transport - Uniport, Antiport and Symport (Glucose and Na+K+ Transporters)

By: HWC, Views: 7402

Some transport proteins bind and transport molecules very selectively. Uniport is the transport of one solute molecule. Symport is the transports of two solute molecules in the same direction. Antiport is the transports of two solute molecules in opposite directions. 1. Glucose bin...

Hormonal feedback loop components & Glucagon (glycogenolysis and gluconeogenesis)

By: HWC, Views: 7538

The endocrine system maintains many body conditions within normal limits with feedback loops. Each endocrine feedback loop maintains homeostasis using the following components: • Stimulus - a change in a body condition. • Production cell - an endocrine cell that produces a hormone after ...

Metaphase I Animation

By: HWC, Views: 5776

This is a cell during metaphase I. For each pair of chromosomes, any gamete produced by this cell could contain either the maternal chromosome or the paternal chromosome. How many different combinations of maternal and paternal chromosomes are possible in the gametes produced by a cell with th...