Abdominal Regions, Peritoneum, Spleen, and Liver Anatomy

Regions of the Abdomen

Two horizontal lines:

  1. The top line links the lowest point of the ribs.
  2. The bottom line joins the points of the elevated iliac crests.

Two vertical lines extend from a point midway between the anterior superior iliac spine and the symphysis pubis.

These lines define nine regions:

  • Right and left hypochondriac
  • Epigastric
  • Right and left lumbar (flank)
  • Umbilical
  • Right and left iliac fossa (inguinal)
  • Hypogastric

Peritoneum

The peritoneum is a smooth serous membrane consisting of two separate

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Hardy-Weinberg Equilibrium and Evolution

Genotype

Number of Individuals

in the Population with

that Genotype

Number of Allele A Contributed to the Gene Pool by that Genotype

Number of Allele a Contributed to the Gene Pool by that Genotype

AA

50

50×2=100

50×0=0

Aa

40

40×1=40

40×1=40

aa

10

10×0=0

10×2=20

Total

100

140

60

Let the letter p stand for the frequency of allele A. Let the letter q stand for the frequency of allele a. We can calculate p and q as follows:

  • p = number of A alleles/total number of alleles = 140/200 = 0.7
  • q = number of a alleles/total number
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Cell Types, Structures, and Division: A Comprehensive Overview

Cell Types and Characteristics

Protoctists

Algae

  • Cell wall: Present
  • Healthy cell: Cytoplasm contains one or more chloroplasts and performs photosynthesis.

Protozoa

  • Actively move using flagella or cilia.

Fungi

  • Thick cell wall made of chitin.
  • Heterotrophic nutrition.

Plant Cells

  • Cell wall composed of cellulose.
  • Membrane contains chloroplasts (green).
  • Do not move if vacuoles are present.

Animal Cells

  • Some have flagella, many organelles in the cytoplasm.

Multicellular Organisms

Animal Tissues

  • Epithelial: Covers internal
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Cellular Components and Their Functions

Cytosol

The cytosol is the semi-solid fraction of the cell, primarily composed of water, salts, and both small and large water-soluble molecules. It includes supramolecular complexes such as the cytoskeleton, ribosomes, and centrioles. Additionally, it contains polysaccharide granules, lipid droplets, and pigments. The majority of cellular metabolism, including protein synthesis in ribosomes, occurs here.

Cytoskeleton

The cytoskeleton is a network of protein fibers that maintains cell structure and

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Understanding Viruses: Composition, Types, and Cycles

Concept of Virus

Viruses are very simple, microscopic particles that consist only of a nucleic acid (viral genome) and some envelope proteins (capsid). Therefore, they are not cells and are not surrounded by membranes, forming acellular organizational systems. They exist on the boundary between the living and the nonliving.

Composition of Viruses

The composition of a virus is very simple, consisting of a single molecule of nucleic acid, which can be:

  • Single-stranded RNA
  • Double-stranded RNA
  • Single-stranded
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Biological Energy Processes and Genetic Variation

Biological Processes that Generate Energy

1. Photosynthesis: The process by which plants, algae, and some bacteria capture and utilize light energy to convert inorganic matter from their external environment into organic matter used for growth and development.

2. Chemosynthesis: The biological production of organic matter from molecules of carbon and other nutrients, using the oxidation of inorganic molecules.

3. Anaerobic Respiration: A biological process of oxidation-reduction of sugars and other

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