Human Biology Course Overview

Human Biology Course

• Biology is the study of living organisms and their interactions with the surrounding environment
• Biology encompasses various disciplines, including biochemistry, physiology, anatomy, and histology
• Human biology studies all aspects of humans, including evolution, genetics, ecology, anatomy, physiology, development, anthropology, and nutrition

Characteristics of Living Organisms

• Metabolism: The sum of chemical reactions within cells, providing energy for vital processes and synthesizing new organic material. Includes anabolism (building) and catabolism (breaking down) processes.
• Response to stimuli: Organisms react to various stimuli (e.g., light, chemicals). Positive responses move towards a stimulus, while negative responses move away.
• Reproduction and development: Single-celled organisms reproduce by division or budding. Multicellular organisms have specialized reproductive cells (sperm and ova). Growth and development are guided by genes.
• Homeostasis: Maintaining a stable internal environment despite external changes. An example is thermoregulation (regulating body temperature).
• Evolution: The change in characteristics of a population over time due to successful traits aiding in reproduction and survival in a specific environment. Adaptations can be structural, behavioral, or physiological.
• Organization: Living things have multiple levels of organization, from molecules to cells, tissues, organs, organ systems, and finally, organisms, populations, communities, ecosystems, and the biosphere.

Microscopy

• Cell theory development is concurrent with microscope advancement.
• Microscopes, from single-lens light microscopes to electronic microscopes, enable magnification of specimens for detailed examination.
• Light microscopes employ visible light to magnify. Parts include the ocular lens, objective lens, nosepiece, stage, condenser, diaphragm, light source, arm, coarse and fine focus, and base.
• Electronic microscopes use electrons to magnify, producing high resolution images.

Cell Theory

• The cell theory postulates that all organisms are composed of one or more cells, all life functions occur within cells, all cells come from existing cells, and the cell is the basic unit of life.
• Key figures: Robert Hooke, Anton van Leeuwenhoek, Matthias Jakob Schleiden, Theodor Schwann, Robert Brown, Robert Remak, Rudolf Virchow, and others.

Modern Cell Theory

• Genetic material (DNA) is transmitted during cell division.
• All cells have similar basic chemical composition.
• Energy flow takes place within cells.

Classification

• Classification involves grouping organisms based on shared structural similarities.
• Organisms are categorized hierarchically (kingdom, phylum, class, order, family, genus, species) from the largest to smallest groups.
• a Species is the smallest group of organisms within the hierarchy. Members of a species are capable of interbreeding and producing fertile offspring.

Kingdoms and Domains

• Kingdoms are the largest groups of living organisms. There are five kingdoms: prokaryotes, protoctista, fungi, plants, and animals.
• Kingdoms are further subdivided into phyla based on shared characteristics.
• Examples include organisms in the Arthropod phylum (arthropods).

Linnaeus System of Classification

• A hierarchical system of classifying organisms.
• Categories from largest to smallest: Kingdom, phylum, class, order, family, genus, species.

Binomial System

• A system of assigning two Latin names (genus and species) to each organism, used in scientific naming.

Scientific Methods

• Scientists use a series of steps (observing, questioning, hypothesizing, experimenting, analyzing data, drawing conclusions) to investigate and understand the natural world.
• The scientific method involves hypotheses that can be tested.
• Experiments are performed to gather evidence to support or reject a hypothesis. Data analysis is conducted on the outcome of the experimental procedures.

Observation

• Observation: Data collected from the senses; can be enhanced with tools.
• Includes direct observation: using the senses.
• Also includes instruments that can extend the senses (e.g., microscopes, thermometers, ultraviolet light detection).

Hypothesis

• A logical, testable explanation for a scientific question.
• A well-defined and educated guess about the possible outcomes of scientific inquiry.
• Hypotheses are based on prior knowledge.

Experiment

• A special investigation conducted under controlled conditions to test a hypothesis.
• Experiment typically involves manipulating independent variables to observe their effects on dependent variables.
• Control variables are maintained constant to eliminate other potential influences.

Data Analysis

• Descriptive statistics: Summarization of data via values such as mean, average, and standard deviation. Useful for understanding distributions of data.
• Inferential statistics: Used to draw conclusions about larger populations and groups. T-test is a common technique used in this arena, and is used when comparing the mean value of the experimental dataset to predicted values or to values obtained from a control group.

Conclusion

• If data supports the hypothesis, the hypothesis is accepted; if not, it is rejected.
• Well-designed and executed experiments remain valid even when the hypothesis is rejected.

Communicate Results

• Scientists communicate experimental results through peer-reviewed articles published in scientific journals.
• Articles are reviewed by other experts in the field for validity and significance before publication.

Chemistry of Living Beings

• Matter: Any substance that takes up space and has mass; elements are pure substances.
• There are almost 120 known elements. Most are metals. Nonmetals are a smaller group, and include hydrogen and oxygen. Carbon is vital to living things.

Atoms

• Atoms: The smallest part of an element that maintains the element's traits.
• Atoms are composed of subatomic particles.

Compounds

• Compounds: Substances consisting of two or more elements that are combined in definite ratios or proportions.
• Molecules: The smallest particle of a compound having the chemical characteristics.

Chemical Bonds

• Nonpolar covalent: Sharing electrons equally.
• Polar covalent: Unequal sharing of electrons.
• Ionic: Transfer of electrons.
• Hydrogen: Attraction between a hydrogen atom and a strongly electronegative atom.

Chemical Compounds of Living Things

• Biochemical compounds: Compounds in living organisms that carry out life processes.
• Carbon plays a significant role in forming stable bonds with many elements leading to huge complexity and diversity.

Carbohydrates

• These compounds are composed of carbon, hydrogen, and oxygen.
• Monosaccharides (e.g., glucose, fructose, galactose) are the simplest type.
• Polysaccharides (e.g., starch) are complex molecules combining many monosaccharides.

Explore the fundamentals of human biology, covering essential topics such as metabolism, response to stimuli, and reproductive processes. This quiz delves into the characteristics of living organisms and their biological functions, ideal for students seeking a comprehensive understanding of biology.