Nervous and Digestive Systems: Invertebrates & Vertebrates
Nervous System
Function: The nervous system receives, integrates, and transmits information from the external and internal environment, as well as coordinating and monitoring responses. Receptors, sensory nerve pathways, modulators, motor nerve pathways, and effectors are involved.
Nerve Impulse
A nerve impulse is the transmission of signals coming from neurons. It consists of a resting potential, depolarization, action potential, and repolarization. The excitability threshold is the minimum intensity
Read MoreCell Biology: Organelles, Molecules, and Metabolism
Cellular Components and Functions
- Vacuole: An organelle in plant cells for water storage, secretion, and waste.
- Eukaryotic Cell: Contains genetic material enclosed by a nuclear membrane and membranous organelles.
- Prokaryotic Cell: Hereditary material dispersed in the cytoplasm, lacking membranous organelles.
Cell Theory
The cell is the structural and functional unit of all living organisms.
Organelles
- Membranous Organelle: Cell structure with one or two membranes, fulfilling specific functions.
- Nucleus:
Marine Life and Ocean Ecosystems: A Comprehensive Study
Marine Life and Ocean Ecosystems
Benthic Organisms
Epifauna: Organisms living on the surface of the ocean floor, such as corals, mussels, sea stars, sea urchins, and sponges.
Epibenthos: Organisms that live in association with the seafloor but swim up into the water column, such as carpet sharks, shrimp, and rays.
Hard Bottoms: Animals adapted to live on the top of rocks.
Infauna: Organisms that live burrowed into the ocean floor, such as clams and polychaetes. They use tubes for food and oxygen supply.
Read MoreDNA, Genes, and Chromosomes: Understanding Heredity
Before the Nineteenth Century: Inheritance by Mixing
Sex cells combine hereditary material and mix as do colors. According to this theory:
- White Animal + Black Animal = All descendants are mid-gray.
Mid-Nineteenth Century
Gregor Mendel (1821-1884)
- Modern genetics.
- Inherited characteristics are transmitted by individual factors that are dispatched each generation.
- Not-ruined compote that was identified as hereditary material.
Mendel’s Experiments
Mendel’s experiments with peas involved smooth peas and wrinkled
Read MoreAcellular Bodies, Viruses, and Cellular Organelles
Acellular Bodies and Viruses
Acellular bodies are not living organisms.
Viruses
-Virus: Small molecules of DNA or RNA covered by a protein capsule (capsid). This capsule, composed of capsomeres, may have a neck, an outer shell, and various structures. Viruses are responsible for numerous parasitic infections and diseases. They are very small and can only live within other cells, using the host cell’s organelles to multiply.
Viral Life Cycle
Cycle of a virus:
- Attachment: The virus binds to the surface
Nervous and Endocrine Systems: Functions and Mechanisms
The Nervous System: Structure and Function
The nervous system comprises the central nervous system (CNS) and peripheral nerves. It is composed of cells called neurons that can carry rapid electrical impulses.
Nerve Impulse Conduction
Nerve impulses are conducted from receptors to the CNS by sensory neurons, within the CNS by relay neurons, and from the CNS to effectors by motor neurons.
Resting and Action Potentials
- Resting potential: The electrical potential across the plasma membrane of a cell that