Plant and Animal Kingdoms: Characteristics and Classification
Plants: Characteristics and Classification
Plants appeared millions of years ago, approximately 500 million years ago. It is believed that they evolved from some group of green algae that were able to adapt to the terrestrial environment. This hypothesis is supported because plants and algae share several characteristics:
- Both own photosynthetic pigments.
- Both store starch reserves.
- They have cellulose cell walls.
- They make their cell division after mitosis through a cellulose partition, the phragmoplast.
Stellar Evolution and the Fate of the Universe
How Do Stars Release Energy?
The core of a star is an intense environment. The pressures are enormous, and the temperatures can be greater than 15 million Kelvin. These are the kind of conditions you need for nuclear fusion to take place. Once these conditions are reached in the core of a star, nuclear fusion converts hydrogen atoms into helium atoms through a multi-stage process.
To complete this process, two hydrogen atoms are merged together to form helium. This whole reaction is exothermic, and
Read MoreHuman Culture: Key Factors and Social Learning
Humanizing Factor: Culture
Culture is a main humanizing factor. In the process of hominization, over millions of years, not only is the production of hominization important, but also culture is in everything and produces humanization. The social realm determines the appearance of culture. If we consider that the biological and genetic connection with the world is our natural dimension, then we can consider culture as the set of information acquired through social learning. Therefore, animals would
Read MoreSpanish Peninsular Relief: Formation and Characteristics
Characteristics of the Spanish Peninsular Relief
The relief is the set of forms presented by the Earth’s surface, which are dynamically constructed and destroyed. It is solid-form and determined by the width and extension of the coast. The rectilinear layout offers few refuges for navigation. The high average altitude is due to the extensive existence of a central plateau, and mountain ranges that cross the peninsular territory. The average altitude is 660m, with some areas reaching 1300m, making
Read MoreAbiotic and Biotic Factors in Terrestrial and Aquatic Ecosystems
Abiotic and Biotic Factors in Ecosystems
Conditions or Environmental Factors in One Place
Abiotic Factors
- Physics: Light and shadow, wind, barometric pressure, altitude, solar radiation.
- Chemicals: The amount of air and soil water, salinity, dissolved oxygen.
Biotic Factors
- Intraspecific: Family association, colonial, social, gregarious.
- Interspecific: Mutualism, commensalism, renters, predation.
Abiotic Factors Determining the Terrestrial Environment
- Light: The main source of energy in most ecosystems and
Water Treatment and Building Plumbing: Essential Practices
Water Treatment Processes
44. What Is the Purpose of Aeration in Drinking Water?
Aeration is the process by which water is placed in intimate contact with air to amend the concentrations of dissolved gases or volatile substances.
45. Water Sample Analysis: Clay Particles in Suspension
When analyzing a water sample, a high concentration of clay particles in suspension is observed. What correction treatments should be applied to the water from which the sample was taken?
Filtration