Biology and Botany Overview

Biology and Botany

• Biology is the study of life
• Botany is a discipline within Biology focused on living things called plants and similar organisms that aren't animals
• Botany studies why plants are important
• Plants start most food and energy chains and provide oxygen, food, and medicine.
• Plants are divided into two groups: plants 1 and plants 2
• Plants 1 are all organisms that use sunlight, water, and carbon dioxide to make organic compounds.
• Some plants 1 can also be bacteria or animals.
• Plants2 are organisms from the Plantae kingdom, generally multi-tissued, primarily terrestrial, and eukaryotic photosynthetic organisms.

Plants 2

• Plants2 are generally defined by their evolutionary relationships (taxonomical) not just their physical characteristics
• Some Plants2 are fully parasitic plants (e.g., mycoparasites like Pterospora, root parasites like Hydnora, stem parasites like Cuscuta, internal parasites like Pilostyles)
• These Plants 2 don't make their food through photosynthesis.

Levels of Organization in Organisms

• The chemical level is the most basic level of organization, including atoms and molecules.
• An atom is the smallest unit of a chemical element
• Atoms combine chemically to form molecules.
• Many types of atoms and molecules associate to form cells.
• Cells combine to form tissues.
• Tissues organize into functional structures called organs (e.g., roots, leaves).
• Organs combine to form organ systems.
• Organisms interact to form more complex levels of biological organization.
• All the members of one species living in the same geographic area at the same time make up a population.
• Groups of populations of different species that interact together are a community.
• A community with its nonliving environment is an ecosystem.
• All of Earth's ecosystems form the biosphere.
• Ecology is the study of how organisms interact with each other and their environment.

Naming Organisms

• Biologists use a binomial system of naming organisms.
• This system identifies approximately 1.8 million species of extant organisms, with estimations of millions more undiscovered.
• Systematics is the field of biology that studies the diversity of organisms and their evolutionary relationships.

Taxonomy and Classification

• Taxonomy is the science of naming and classifying organisms.
• Plant taxonomy specifically focuses on classifying and identifying plants
• A hierarchical system of naming and classifying is used (e.g., kingdom, class, order, family, etc.).
• This system is known as the binomial system or binomial nomenclature.
• The two-part system includes a genus name followed by a species name (e.g., Homo sapiens)
• International codes of botanical nomenclature (ICBN) were created to ensure standardized and stable naming system
• This helps avoid confusion in the use of names.

The Tree of Life

• Biologists classify organisms based on evolutionary relationships.
• A clade is a group of organisms with a common ancestor.
• Evolutionary relationships are based on similar characteristics (structural, developmental, behavioral, and molecular)
• The classification of organisms is a work in progress; classifications often change as new findings are discovered and the tree of life redrawn.
• Organisms fall into three domains: Bacteria, Archaea, and Eukarya
• Organisms can be further subdivided into kingdoms.

Modes of Nutrition

• Plants can be divided based on their mode of nutrition
• Autotrophic nutrition is when an organism makes its own food from inorganic sources (e.g., plants using photosynthesis).
• Phototrophic nutrition is when an organism uses light energy to make its own food.
• Chemotrophic nutrition is when an organism obtains energy by oxidizing inorganic chemicals.
• Heterotrophic nutrition is obtaining energy from consuming other organisms. This involves different types, such as Parasites, Saprotrophs, carnivorous plants.

Heterotrophic Plant Classification

• parasitic plants depend on other living things for nutrients
• saprophytic plants use dead or decaying organic matter for nutrients
• Carnivorous plants have adaptations to capture and consume insects and other small animals.