Evolutionary Theories

Punctuated Equilibrium vs. Neo-Darwinism vs. Neutralism

• All three theories propose evolutionary change.
• Punctuated Equilibrium: Evolutionary changes occur rapidly and abruptly.
• Neo-Darwinism: Evolutionary changes occur gradually over time.
• Neutralism: Most mutations have no effect on natural selection.

Barriers to Genetic Isolation

• Geographical
• Sexual
• Physiological
• Chromosomal
• Ethological

Ecological Concepts

Abiotic and Biotic Factors

• Abiotic Factors: Non-living factors that affect ecosystems (e.g., temperature, pH, wind)
• Biotic Factors: Living components that affect ecosystems (e.g., disease, predation, competition)

Biomass

- Total dry weight of organic matter in organisms or ecosystems. - Includes carbohydrates, proteins, etc.

Ecosystems

Water: The Essential Solvent

Water constitutes approximately 80% of the human body and plays a crucial role in biological systems.

Role of Water as a Solvent

Water is an important solvent, a liquid in which substances (or solutes) are dissolved, forming a solution. In a solution, the solvent is typically present in a greater amount than the solute.

Metabolic reactions, which are vital for life, can only take place if the chemicals reacting are dissolved in water.

Other Vital Functions of Water

Water is also essential for other reasons, such as being the primary component of plasma, the liquid part of blood, facilitating transport throughout the body.

Carbohydrates: Energy & Structure

Carbohydrates include starches and sugars, and are composed of... Continue reading "Fundamental Biological Molecules: Water, Carbohydrates, Lipids, Proteins, DNA" »

Proteins

  

∑ - Amino acids are linked together by condensation to form polypeptides.

• Amino acids are then combined to create large polypeptides through condensation reactions which produce many molecules of water (i.e. polypeptides - Hemoglobin and Insulin).

B  Skill: Drawing molecular diagrams to show the formation of a peptide bond.

• Basic dipeptide shown to the right. Students should practice drawing  with a variety of different amino acids (different “R” groups)
  
• Every peptide bond should be between the NH2 (amine group) and the COOH (carboxyl group). One H comes from the NH2 and an –OH group comes from the –COOH group to produce H2O
  
• Condensation reaction
  

∑ - There are 20 different amino acids in polypeptides synthesized on ribosomes.

Complete the statements.

1. There are 206 bones in the skeletal system of an adult.
2. Babies are born with almost 300 bones in their body.
3. The largest bone in the body is the femur.
4. The only floating bone is called the hyoid and it is located under the tongue.
5. The skeletal system has two main jobs: protect and support.

Complete the table with the functions of the skeletal system.

Label the parts of the skeletal system.

• Bones: They

Biology 105/106: Exam 1 Study Material

This document outlines key concepts for Biology 105/106 Exam 1, covering fundamental principles of science, life, cells, metabolism, and energy, along with essential lab topics.

Chapter 1: The Scientific Process

• Science as a Process:
  1. Observation: Noticing phenomena.
  2. Question: Forming a formal hypothesis.
  3. Hypothesis: A testable explanation for an observation.
  4. Experimentation: Testing the hypothesis.
  5. Data Analysis: Drawing conclusions from results.
  6. Communication: Sharing findings and restarting the process with new questions.
• Hypothesis vs. Prediction: Understand the distinction.
• Experiments:
  • Controls: Elements kept constant to ensure valid results.
  • Variables:
    • Independent Variable: The factor manipulated by the experimenter.

Applications of Proteins

Rubisco

• Catalyzes the CO₂ fixation reaction in the Calvin cycle.
• Full name: ribulose bisphosphate carboxylase.
• One of the most abundant and important enzymes.

Insulin

• Hormone produced by pancreatic beta cells.
• Reduces blood glucose levels by promoting glucose absorption.
• Binds reversibly to cell membrane receptors.

Immunoglobulins (Antibodies)

• Y-shaped proteins produced by plasma B cells.
• Identify and neutralize foreign pathogens.
• Act as markers for pathogen destruction by phagocytes.
• Each antibody is specific to a particular pathogen.

Rhodopsin

• Biological pigment in retinal photoreceptor cells.
• Consists of a retinal molecule surrounded by an opsin polypeptide.
• Light absorption changes its shape, sending a nerve impulse to the brain.

Balanced Diet and Nutrients

We need to eat a wide variety of foods to obtain all the necessary substances. A diet that includes a variety of foods is called a balanced diet. Carbohydrates, proteins, fats and oils (lipids), vitamins, and minerals are essential nutrients. These nutrients provide the raw materials our bodies need to function properly.

Food Testing

We can conduct tests to identify the substances present in our food. For example, starch turns iodine a blue-black color.

Nutrition Information Labels

Nutrition information labels on food products tell us about the food's composition and the amount of energy stored within it. Energy is measured in kilojoules (kJ). A person's daily energy needs depend on several factors:

• Level of activity
• Age
• Gender

Food... Continue reading "Balanced Diet and Nutrition: A Guide to Healthy Eating" »

The Nervous System

Central Nervous System (CNS)

Brain

Located inside the head, the brain is divided into three regions:

• Cerebrum: Receives and interprets information from the sense organs. Language, memory, learning, and thinking are located here.
• Cerebellum: Plays an important role in motor control and motor learning. It acts in coordination and precision.
• Brain Stem: Joins the brain and spinal cord. It controls involuntary actions.

Spinal Cord

A long, thin tube running inside the backbone, the spinal cord transports information from the brain to the nerves and carries reflexes.

Protection of the CNS

• Hard: Bones protect the CNS. The brain is protected by the skull, and the spinal cord is protected by the backbone.
• Soft: Meninges, a system of membranes

Population Dynamics and Carrying Capacity

Population dynamics refers to how populations change over time in response to environmental factors.

• The Carrying Capacity of a Habitat

  The carrying capacity (K) is the maximum number of individuals in a population that a specific environment can support sustainably.

• When the carrying capacity of a habitat is reached, the population size varies around that value due to two main causes:

  • Fluctuations: These are non-periodic changes caused by unpredictable environmental factors (e.g., disease, drought).
  • Cyclical Changes: These are predictable changes, such as seasonal variations (winter, spring) or the regular interaction between predators and prey populations.

Population Growth Strategies (K and R Selection)

The Function of Reproduction

Reproduction is a fundamental biological process involving several key stages:

• Gametogenesis: The formation of gametes (sex cells) which takes place in the gonads.
• Fertilization: The joining of two gametes to form a zygote, typically an internal process in humans.
• Embryo Development: Cell division increases the number of cells that make up the zygote, which becomes an embryo. This continues developing and eventually becomes a fetus.
• Childbirth: The birth of the baby, which is fully formed and alive.
• Development: The baby grows and reaches maturity (adulthood).

Sexual Maturity and Development

Sexual maturity involves significant changes, including the development of primary and secondary sex characteristics.

Puberty

Between... Continue reading "Human Reproduction: Stages, Systems, and Development" »