Notes, summaries, assignments, exams, and exercises for Biology for Secondary education

Nutrition, Mobility and Cell Characteristics

Nutrition

Nutrition: Variety — plants (autotrophs), animals (heterotrophs).

Mobility

Mobility: Variety — plants (immobile), animals (mobile).

Growth

Growth: Plants (often indeterminate / unlimited), animals (typically determinate / limited).

Cellular Coverings

Cell coverings: Plants: cell wall and cell membrane; Animals: plasma membrane.

Similarities of Living Beings

Similarities: assimilation, sensitivity, autoregulation and reproduction.

Cell Composition and Organelles

Cell composition: Life composed of abundant protoplasm; cells possess a cell membrane, cytoplasm, and a nuclear membrane (karyotheca) with a nucleus.

There are a variety of structures in the cytoplasm (organelles): ribosomes, endoplasmic

Cellular Structures and Functions

Microvilli

Microvilli are finger-shaped projections, most frequently found in cells of the kidney and small intestine. Their primary function is to increase the absorption of nutrients.

Interdigitations

Interdigitations are located on the sides of cells. They increase the membrane surface area and promote functional integration.

Pits

Pits are found on the basal (bottom) face of the cell. They increase its surface area, provide resistance to cellular movements, and determine protein binding at the base of the cell.

Cilia

Cilia are short, mobile appendages developed by lipid-transporting cells or mucous-secreting cells. They exhibit a whipping movement. Their function is to help cells move through the human respiratory

Biological Taxonomy and Classification

The classification of living beings is known as taxonomy. The hierarchical categories are: kingdom, phylum, class, order, family, genus, and species.

The Five Kingdoms

• Plants: Ferns, gymnosperms, mosses.
• Fungi: Mushrooms, molds, yeasts.
• Animals: Mammals, birds, amphibians, fish.
• Protoctists: Protozoa (ciliates, amoebae) and algae (brown, green, and red).
• Monera: Bacteria.

Species and Genetics

A species is a group of individuals with similar characteristics that breed among themselves to produce fertile offspring.

Factors Influencing Variation

• Inheritable: Changes in genetic information.
  • Mutations: Errors in the DNA instructions of cells.
  • Recombination of genes: Occurs during sexual reproduction, where genes from male

The Circulatory System

The circulatory system, also known as the cardiovascular system, is responsible for transporting blood throughout the body. It comprises the heart, blood, and blood vessels. Blood itself is a specialized connective tissue with vital transport functions.

Blood Composition

Blood is composed of two main parts:

• Plasma: This is the fluid, yellowish liquid part of the blood, primarily made of water with various dissolved substances.
• Blood Cells: Formed in the red bone marrow, there are three main types of blood cells:
  • Red Blood Cells (Erythrocytes): These are essentially bags of red pigment called hemoglobin, responsible for oxygen transport.
  • White Blood Cells (Leukocytes): These cells contain a nucleus and are crucial for the body'

Understanding Diet and Nutrition

What is Diet?

Diet: The amount and type of food we consume.

Types of Diets

Balanced Diet: A healthy diet provides the body with the right amount of energy and different types of nutrients.

Mediterranean Diet: This is a balanced diet that combines all foods properly.

Genetically Modified Organisms

GMO Foods: These are produced from organisms that have had genetic material from another living being introduced.

Food Preservation and Additives

Food Preservation Methods

Food can be preserved using chemical and physical methods:

• Heating foods to high temperatures for a few seconds can eliminate a number of bacteria.
• Preservation by cold (refrigeration/freezing).
• Freeze-drying eliminates water from food.
• Chemical preservation uses

The Nervous System

The nervous system is a biological system that enables very complex beings to interact with what surrounds us. We can say that it is a huge network responsible for the collection of internal and external stimuli. It processes these stimuli to generate the response that the decision center (brain) considers optimal.

There are two main divisions:

• Central Nervous System: Consists of the brain and spinal cord.
• Peripheral Nervous System: Includes all the nerves of the body that connect internal and external stimuli to the central nervous system.

Peripheral Nervous System

The peripheral nervous system includes different types of nerves:

• Sensory Nerves: Transmit information from sensory receptors (like those for touch, pain, temperature)

Gregor Mendel's Contributions to Genetics

Note: This section details the scientific method applied to the study of inheritance.

Mendel's Scientific Method in Inheritance

Formulation of the Problem:

How are characteristics passed down from parents to offspring?

Hypothesis:

Sex cells contain structures responsible for the transmission of characters.

Experiment (Proof):

Crosses were made with purebred pea plants. In Cross 1, one character varied while six others remained constant.

Results and Conclusions:

Cross 1: All F1 generation individuals expressed the dominant character. In the F2 generation, the phenotypic ratio was 3:1.

Conclusions: Gametes contain factors responsible for character transmission, and each character is determined by two factors.

Key

Human Digestive System

Two Types of Digestion

• Mechanical digestion: The physical breakdown of food.
  • Examples: Chewing in the mouth, churning in the stomach, and segmentation in the small intestine.
• Chemical digestion: Breaking down molecules with enzymes and acids.
  • Examples: Salivary amylase in the mouth, pepsin in the stomach, and pancreatic enzymes in the small intestine.

The GI Tract Path

Mouth → Pharynx → Esophagus → Stomach → Small Intestine → Large Intestine → Rectum → Anus.

Accessory Organs and Their Roles

• Salivary glands: Produce saliva.
• Liver: Produces bile.
• Gallbladder: Stores and concentrates bile.
• Pancreas: Produces digestive enzymes and bicarbonate.

Digestive Juices and Functions

• Saliva: Moistens food and initiates carbohydrate

The Ovarian and Menstrual Cycles

The ovarian and menstrual cycles are monthly processes controlled by hormones that prepare the female body for a possible pregnancy, typically lasting about 28 days.

The Ovarian Cycle

• Follicular Phase (Days 1–13): Follicles develop in the ovary; one becomes dominant and produces estrogen.
• Ovulation (Day 14): The mature egg is released.
• Luteal Phase (Days 15–28): The empty follicle becomes the corpus luteum, producing progesterone to prepare the uterus for pregnancy.

The Menstrual Cycle

• Menstruation (Days 1–5): The uterine lining is shed.
• Proliferative Phase (Days 6–14): Estrogen causes the endometrium to thicken.
• Secretory Phase (Days 15–28): Progesterone maintains the lining.

If fertilization does not occur,...

Reproductive Cycles

For a successful reproduction, the ovarian and uterine cycles must be synchronized.

The Ovarian Cycle

The ovarian cycle consists of the maturation of an ovule every 28 days. Its phases include:

• Follicular: Days 1-14; follicle development occurs, and only one will mature.
• Ovulation: Day 14; the release of the matured egg into the fallopian tube.
• Luteal: Days 15-28; the empty follicle produces progesterone.

The Uterine Cycle

The uterine cycle prepares the uterus for the implantation of a fertilized egg. Its phases include:

• Menstrual: Days 1-5; bleeding occurs that eliminates the endometrium.
• Proliferative: Days 5-14; the endometrium regenerates and the cervix opens up. The uterus produces an egg-white type of discharge.
• Secretory: Days