Biology Concepts: SA:V Ratio & Organelles

SA:V Ratio Calculation

• A cube with a side length of 3 cm has a surface area of 54 cm² and a volume of 27 cm³.
• The SA:V ratio for this cube is 2:1.
• Larger cubes have a smaller SA:V ratio because the volume increases faster than the surface area.

Small Intestine Structure

• The small intestine is designed for efficient food absorption by increasing surface area, providing time for digestion, and containing structures for nutrient absorption.

Organelles: Membrane-bound vs. Non-membrane-bound

• Membrane-bound organelles are primarily composed of phospholipids, examples include the Endoplasmic Reticulum and Mitochondria.
• Non-membrane-bound organelles are primarily composed of proteins, examples include Ribosomes and the Cytoskeleton.

Prokaryotic Organelles

• Prokaryotes lack membrane-bound organelles because they evolved before the presence of oxygen in the atmosphere.
• The evolution of oxygen led to the development of cellular respiration, which is found in eukaryotes with membrane-bound organelles.

Characteristics of Prokaryotes, Chloroplasts, and Mitochondria

• Prokaryotes, chloroplasts, and mitochondria share these characteristics:
  • They contain their own DNA and RNA.
  • They have a double cellular structure.
• Mitochondria and chloroplasts are considered "first cells" due to their shared characteristics with prokaryotes.

Optional Quiz Make-up

• Students can replace one missing or low quiz grade from quarter 1.
• Students can choose any allowed quiz if they were absent for one or no quizzes.
• Students must make up a quiz they missed if they were absent for more than one.
• The make-up quiz must have five new questions covering the same or similar topics as the original quiz.
• Questions should not be copied from the original quiz.
• No more than one question should require only identification.
• The quiz does not need to be formatted as a quiz.
• Questions should be answered in complete sentences, unless the question requires labeling or drawing.
• The quiz must be handwritten and labeled correctly.
• A perfect score will be given if all five questions and answers are related to the original quiz topic and answered correctly.

Quiz Requirements

• Questions should use task verbs like analyze, apply, compare, contrast, describe, explain, evaluate, predict, and justify.
• Students can refer to a sample quiz for an idea of what the make-up quiz should look like.