Prokaryotic vs Eukaryotic Cells Quiz

Prokaryotic and Eukaryotic Cell Similarities and Differences

• Prokaryotic cells are small (0.5-5 μm), while eukaryotic cells are larger (often up to 50 μm)
• Prokaryotic cells lack a nucleus, whereas eukaryotic cells have a nucleus.
• Prokaryotic DNA is circular strands in the cytoplasm, while eukaryotic DNA is linear chromosomes in the nucleus.
• Prokaryotic cells have few, if any, membrane-bound organelles, while eukaryotic cells have numerous membrane-bound organelles.
• Prokaryotic cell walls are present but typically made of peptidoglycan. Eukaryotic cell walls (present only in plants) are composed of cellulose.
• Prokaryotic ribosomes are smaller than eukaryotic ribosomes.
• Some prokaryotic cells have capsules, while eukaryotic cells do not.

Magnification Formula

• The formula for magnification is: magnification = size of image / size of real object
• This formula is used to calculate the size of an organelle.
• A triangle diagram helps to visualize relationships between magnification, image size, and actual size.
• Actual size is inside the triangle

Converting Numerical Size

• Numerical sizes can be converted between ordinary and standard form.
• Standard form expresses numbers in the form 'a x 10ⁿ', where 'a' is a number between 1 and 10 and 'n' is an integer.
• Examples of conversions are provided.

Calculating Surface Area and Volume

• Formulas are given to calculate the surface area and volume of different regular shapes (cuboid, cube, and right circular cylinder)
• Examples of these types of shapes are provided through specific formulas.
• A table shows the formulas for various shapes

Gene Linkage and Sex Linkage

• Genetic linkage: Alleles close together on a chromosome tend to be inherited together during meiosis (cross-over).
• Sex linkage: Genes located on sex chromosomes (e.g., X chromosome) are responsible for specific traits whose expression/inheritance patterns differ between males and females.

Multipotent Stem Cells

• Examples of multipotent stem cells in adult humans:
  • Neural stem cells, which differentiate into various nervous system cells (brain).
  • Blood stem cells, found in bone marrow, forming white blood cells, red blood cells, or platelets.
  • Muscle stem cells, crucial for repair because mature muscle cells cannot reproduce.

Potential Uses of Stem Cells in Medicine

• Totipotent embryonic stem cells have the unique ability to form any type of human cell.
• They are used for studying diseases and developing treatments.
• Examples of diseases being studied include Parkinson's, Alzheimer's, heart disease, stroke, arthritis, diabetes, burns, and spinal cord damage.
• They are used to discover what goes wrong in diseases such as cystic fibrosis.

Ethical Considerations of Embryonic Stem Cells

• Arguments "for" the use of embryonic stem cells:
  • Embryos are collections of cells, not humans and require no particular moral attention.
  • Spare embryos are destroyed anyway.
  • Benefit outweighs ethical concerns.
• Arguments "against" the use of embryonic stem cells:
  • Embryos should not be used for research as they have full human status from conception.
  • Lack of consent from embryo.
  • Equivalent to murder.
  • Possible risk of cancer.
  • Possible risk of infection.

Therapeutic Cloning and Somatic Cell Nuclear Transfer

• Somatic cell nuclear transfer involves transferring a nucleus from a patient's skin cell into an ovum (egg) without a nucleus.
• This creates a zygote with the patient's DNA, which can develop into embryonic stem cells.
• The new cells will have the same cell surface molecules as the patient, minimizing rejection issues upon transplantation.

Dangers of Stem Cell Therapy

• Infection risk during injection
• Body rejection of stem cells
• Cancerous risks for stem cells

Nucleus Structure

• Nucleus has a double nuclear envelope.
• Nucleus has nuclear pores.
• Nucleus has a nucleolus.

Diploid Nucleus and Protein Production

• A diploid nucleus contains all the genes an organism requires.
• Cells only use the specific genes needed to produce the necessary proteins to carry out a specific function.

Gene Induction

• Induction, or activation, or expression of a gene is its turning on.

Genes, mRNA, and Proteins

• mRNA is only transcribed from activated genes.
• mRNA then is translated into proteins.
• The proteins within a cell determine its function and specialization.

Lac Operon

• The lac operon is a segment of DNA in some prokaryotes that controls the production of proteins for processing lactose.
• It includes a promoter, operator, and genes for lactose-processing.
• When lactose is absent, a repressor binds to the operator, blocking transcription.
• When lactose is present, it inactivates the repressor, allowing transcription.

Gene Switching Off by Repressor Molecules

• In one way, repressors bind to the promoter region of the gene, preventing RNA polymerase from attaching and thus preventing transcription.
• In a second way, repressors bind to transcription factors, preventing them from attaching to the promoter and thus preventing transcription.

Biological Vocabulary

• Cell: The basic unit of living organisms.
• Tissue: A group of similar cells performing a shared function.
• Organ: A structure formed from different tissues, performing a larger function.
• Organ System: A group of organs working together to perform a complex function..

Adhesion Molecules

• Cell adhesion molecules act as recognition proteins.
• They enable similar cells to connect.

Master Genes and Switching Genes On

• Master genes are responsible for controlling the switching on of genes through transcription factors.
• mRNA from these master genes gets translated into signal proteins.
• These proteins then switch on additional genes responsible for various cell specializations.

Variation

• Variation describes the differences among members of a species.
• Characteristics of an organism are part of its phenotype

Types of Variation

• Continuous Variation: A complete range of measurements with examples like height, hair color, IQ and skin color.
• Discontinuous Variation: Distinct categories with examples like blood type and biological sex.

Mean, Median, Mode of Data

• Mean: Average of a set of numbers.
• Median: Middle number in an ordered data set.
• Mode: Most frequent number in a data set.

Epigenetic Markers During Semi-Conservative DNA Replication

• Epigenetic markers are copied with the DNA during replication ensuring the correct set of genes remain active.

Evidence of Passed-on Epigenetic Changes

• Epigenetic markers are copied into new DNA of daughter cells, maintaining the same gene activation patterns of the parent cell.

Epigenetic Markers in Sperm and Egg Cells during Fertilization

• Sperm and egg cells have epigenetic changes that may determine their structure and function—this is logical.  
• Epigenetic modifications generally do not get passed to the next generation (imprinted genes).
• The vast majority of traits encoded by the genome get reset at fertilization.