Biology

Eukaryotes are organisms with cells with a nucleus and organelles enclosed within membranes. This group includes animals, plants, fungi, and many single-celled organisms. Eukaryotic cells are more complex and larger than prokaryotic cells, which lack a nucleus. Prokaryotes, like bacteria, are simpler and usually smaller. Eukaryotes are vital because their complex cell structure allows for …

Prokaryotes are single-celled organisms without a nucleus. Their name comes from the Greek words “before nucleus,” indicating their simple structure compared to more complex cells. Prokaryotes include bacteria and archaea, which we find in almost every environment on Earth. Prokaryotes are everywhere. They live in soil, water, air, and even inside your body. In fact, …

Archaea are single-celled organisms that form one of the three domains of life, alongside Bacteria and Eukarya. Unlike bacteria, archaea have unique genetic and biochemical traits that make them stand out. These microorganisms thrive in various environments, including some of the harshest places on Earth. In this online biology textbook, you’ll learn about archaea’s definition, …

Plant cells are the basic units of life in green plants, which are photosynthetic organisms belonging to the kingdom Plantae. Plant cells have unique structures that set them apart from other eukaryotic cells, such as those of animals and fungi. By studying plant cells, you can understand how plants grow, develop, and interact with their …

Mendelian genetics, named after Gregor Mendel, forms the basis of our understanding of heredity. Mendel’s experiments with pea plants in the mid-19th century revealed inheritance patterns that changed how we think about genetics. Though initially ignored, Gregor Mendel’s principles are now the foundation of classical genetics. They help us understand genetic diseases, improve crops, and …

Mimicry is a natural phenomenon in which one organism evolves to resemble another. This adaptation helps species survive in their environment. Mimicry involves appearance, sounds, behaviors, and even smells. By imitating other organisms, mimics can avoid predators, catch prey, or attract mates. This article explores the concept of mimicry, its importance, and examples from the …

Microbiology studies microscopic organisms like bacteria, viruses, fungi, and protozoa. These tiny life forms significantly impact our world, affecting everything from human health to environmental processes. By studying microbiology, you gain insights into these organisms’ vital roles and how we can use this knowledge to benefit society. Studying microbiology is essential for several reasons. It …

Epigenetics is the study of changes in gene expression that do not involve changes to the underlying DNA sequence. These changes are brought about by various mechanisms that can turn genes on or off, effectively influencing how cells function and develop. Unlike genetic mutations, which alter the DNA sequence, epigenetic changes are reversible and can …

Microplastics are tiny plastic particles less than 5mm in size. They come from the breakdown of larger plastic items or are manufactured small for specific uses. These tiny particles are a big environmental problem because they are everywhere, including oceans, rivers, and even the air. Microplastics come from sources like cosmetics, clothing, and industrial processes. …

Evolution explains how species change over time through genetic variations and natural selection. It describes how organisms adapt to their environment, leading to the diversity of life we see today. Evolutionary theory helps us understand the origins of species, including humans. We will learn about natural selection, genetic variation, and adaptation. You will also learn …