Mammals: Characteristics, Types, and Evolution
Mammals: Characteristics and Evolution
Mammals are the most evolved of all vertebrates. The majority live on land; their bodies are covered with hair or fur, and the females have glands on their chest, called mammary glands, which secrete milk when the animal gives birth to its young. Among non-land mammals are whales and dolphins, which live in the aquatic environment, and bats, which are flying mammals.
Mammals are homeothermic, or warm-blooded animals, so their body temperature stays fairly constant.
Read MoreEcology: Key Concepts and Definitions
Ecology: A Scientific Discipline
Ecology is the study of organisms in their environment and their relationship to each other.
Environmentalism: A Social and Political Movement
Environmentalism is distinct from ecology, representing a social and political movement.
Types of Interactions
- Intraspecific: Interactions within the same species. Example: mating behavior.
- Interspecific: Interactions with other species. Example: predation and mutualism.
Biotic and Abiotic Factors
- Biotic: Living components. Example:
Genetic Code, Transcription, Translation, and Petrology
Genetic Code
The genetic code is the manner in which nucleobases are arranged in DNA. Genetic information is stored as nucleobases. The information varies based on the bases and their order. To be utilized, the information must be translated.
Features:
- It is universal; all living things are encoded in the same way.
- The basic unit of information is a triplet of bases (e.g., AUG, UUA, AUU, ACC). This can have two meanings:
- It may code for an amino acid.
- It may indicate the start or end of the sequence.
- It
Sensory Receptors, Locomotor System, and Injury Prevention
Sensory Receptors
Sensory receptors are structures formed by nerve cells, specialized to capture and transform stimuli into nerve impulses.
Receptors are classified as:
- Chemoreceptors: Sensitive to chemicals.
- Mechanoreceptors: Sensitive to mechanical stimuli such as touch and pressure.
- Photoreceptors: Light-sensitive.
- Thermoreceptors: Sensitive to temperature variations.
- Nociceptors: Sensitive to intense pressures; responsible for pain.
They are also classified by their location:
- Internal receptors: Located
Understanding the Human Body: Circulatory, Digestive, Urinary, and Respiratory Systems
The Human Body: An Overview of Key Systems
The human body functions through a complex network of interconnected systems. From the tips of our toes to the top of our head, a vital fluid called blood circulates, delivering essential nutrients and removing waste. This journey is facilitated by a sophisticated system of vessels, powered by the heart, a tireless pump located in the center of the chest.
The Circulatory System
The circulatory system, also known as the cardiovascular system, is responsible
Read MoreCell Cycle: Mitosis and Meiosis Explained
The Cell Cycle
The cell cycle is the sequence of modifications that a cell undergoes from its formation until it splits to form two daughter cells. The duration depends on the cell type and environmental conditions. It consists of two main phases:
- Interphase: The initial, long-duration phase where the interphase nucleus is visible. The cell grows and performs many functions. DNA replication takes place at the end of this phase.
- Division Phase (M Phase): The final, short-duration stage where the nucleus