Biology Fundamentals: Cell Structure and Life Processes

Plant and Animal Movement

• Nastic Movement: The movement of the leaves and roots.
• Tropism: Movements that occur in the stems and roots.

Animal Functions

1. Movement

• Voluntary: Walking, swimming, etc.
• Involuntary: Breathing deeply, digestion, etc.

2. Substance Production

The role of the glands.

Nervous System and Glands

The nervous system receives internal or external stimuli via receptors and causes muscles to operate.

Reproduction

Asexual Reproduction

Reproductive cells are not combined; reproduction occurs through division:

1. Fission (Erdibitzea): The nucleus of the cell is doubled.
2. Budding (Gemazioa): A bud forms on the mother cell from the nucleus, resulting in a new individual.
3. Sporulation (Espolurazioa): The mother cell divides into spores.

Sexual Reproduction

Reproductive cells combine. It is divided into three phases:

1. The creation of Gametes (Gametoa).
2. The combination of Gametes (Gametoak).
3. The development of the embryo.

Cell Theory

Proposed by German scientists Schleiden and Schwann in the 19th century:

• All cells are made up of living matter.
• Functions in living beings are composed of cells.
• Each cell originates from other cells, and cells are the basis of all life.

Plant and Animal Cell Characteristics (Eukaryotic Cells)

• Plant Cells: Contain a cell wall surrounding the membrane, and large vacuoles and chloroplasts.
• Animal Cells: Have flexible membranes, lack chloroplasts, and have small vacuoles.

Organelles

• Cell Membrane: Composed of lipids and proteins. It controls the exchange of substances and protects the cell.
• Cytoplasm: Formed by hialoplasm. Chemical reactions occur here.
• Ribosomes (Errebosomak): Lentil-shaped; they produce proteins.
• Endoplasmic Reticulum (Endoplasma-Erretikulu): Stores and distributes proteins generated by the cell.
• Lysosomes (Libosomak): Responsible for digestion and bringing waste substances to the vacuoles.
• Golgi Apparatus (Golgiren Gaikuntzak): Creates carbohydrates (Gluzidoak).
• Mitochondria (Mitokondria): Bean-shaped; responsible for cellular respiration.
• Chloroplasts (Kloroplastoak): Found only in plant cells. Responsible for photosynthesis.
• Cilia and Flagella (Zilioak eta Flageloak): Some structures that aid in movement.
• Nucleus (Core): The control center of the cell, where genetic information is located.

Cell Types

Prokaryote

Primitive cells. They have a cell membrane and cytoplasm, but the nucleus is not defined.

Eukaryote (Mass)

Cells are well developed with a well-defined nucleus.

Chemical Composition Series

Organic Substances

• Water: An essential component of living things; the substance inside the cell.
• Minerals: Involved in the chemical processes of life.

Inorganic Substances

• Proteins: Protect us (e.g., antibodies in viruses).
• Carbohydrates (Gluzidoak): Cells extract energy from them. Participate in cell composition.
• Lipids: A repository of energy.
• Vitamins: Necessary for the proper functioning of living organisms.
• Nucleic Acids: Information is collected and stored for the development and functioning of cells. Two types: DNA and RNA (Arn).