Types of Cells and Tissues in the Human Body
Type of Cells
Cells are classified according to their embryological origin and their morphological and functional characteristics. The four fundamental types are:
- Epithelial cells
- Muscle cells (Myocytes or muscle fibers)
- Nerve cells (Neurons)
- Connective tissue cells
Tissues
Cells with a similar structure and function group together to form tissues. A tissue consists of a set of cells, similar in structure and function, and the substance that surrounds them (intercellular substance).
Tissue Types
There are
Read MoreUnderstanding Mitosis and Cell Division in Animal and Plant Cells
Mitosis and Cytokinesis: Cell Division in Animal and Plant Cells
Mitosis is the process of cell division where a single parent cell divides to produce two identical daughter cells. This process is essential for tissue growth and renewal in multicellular organisms. Cytokinesis, on the other hand, refers to the division of the cytoplasm, which occurs after mitosis. While the fundamental processes of mitosis and cytokinesis are similar in both animal and plant cells, there are some key differences.
Differences
Read MoreUnderstanding Biological Macromolecules: Structure, Function, and Metabolism
Biological Macromolecules
Carbohydrates
Structure
Glucose: a monosaccharide
Maltose: a disaccharide
Function
Monosaccharides: used as energy sources
Disaccharides: used as transport molecules to move carbohydrates around the body
Cellulose and Amylose
| Feature | Cellulose | Amylose |
|---|---|---|
| Source | Plants | Plants |
| Glucose Subunit | Beta glucose | Alpha glucose |
| Bonds | 1-4 glycosidic linkages | 1-4 glycosidic linkages |
| Branches | Linear | Linear |
Amylopectin and Glycogen
| Feature | Amylopectin | Glycogen |
|---|---|---|
| Source | Plants | Animals |
| Glucose Subunit | Alpha glucose | Alpha glucose |
| Bonds | 1- |
Genetics: Sex-Linked Genes, Pedigrees, and Genetic Disorders
Sex-Linked Genes
Sex-linked genes are located on both the X chromosome and the Y chromosome.
Formation of a Barr Body
The formation of a Barr body inactivates one whole X chromosome in a female cell.
Pedigree in Figure 14–3
Examine the pedigree in Figure 14–3. The allele for the presence of a white forelock is dominant. Therefore, we can tell from the chart that in the couple labeled 2
Trait in Pedigree in Figure 14–5
The trait in pedigree in Figure 14–5 has two alleles: P (dominant) and p (recessive)
Read MoreCell Nucleus: Structure and Function
The Cell Nucleus
The cell nucleus, an organelle first described by Franz Bauer in 1802, is a structure found in eukaryotic cells. It contains the cell’s DNA and is bounded by the nuclear envelope, communicating with the cytoplasm through nuclear pores. The nucleus has two primary functions:
- To regulate chemical reactions within the cell.
- To store the cell’s genetic information.
Its diameter can range from 2 to 25 μm.
Besides genetic material, the nucleus also contains proteins that regulate gene expression.
Read MoreUnderstanding the Human Immune and Respiratory Systems
Innate and Adaptive Immunity
What is Immunity?
1. Innate immunity refers to the body’s natural defense mechanisms that are present from birth and provide immediate, non-specific protection against pathogens. Adaptive immunity, on the other hand, is a specific immune response that develops over time as the body encounters and recognizes specific pathogens.
What is a Pathogen?
2. A pathogen is a disease-causing microorganism, such as bacteria, viruses, fungi, or parasites.
Barriers of Innate Immunity
3.
Read More