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

The Lymphatic System

The lymphatic system is a crucial part of the immune system, especially in the immune response.

• Lymphatic vessels allow accumulating lymph to carry and filter out pathogens through lymph nodes.
• The majority of lymphocytes are found in the lymphatic system. For example, T cells mature in the thymus while B cells mature in the bone marrow.

Humoral Immune System

The humoral response, which occurs in blood and lymph, primarily uses B cells to combat pathogens directly. B cells are triggered and activated by helper T cells before they can fight pathogens. When B cells encounter a pathogen they recognize, they engulf the foreign substance and display the antigens on their cell surface. Helper T cells then bind to these antigens, triggering...

Ecosystem

Abiotic (physical, chemical), Biotic (population mateixa, community totes)

get food by: feeding, trophic relation shipsTrophic levels: 1) Producers 2)Consumers 3)Decomposers (bacteria, fungi)Organic materials: from living beings.
Photosynthesis: plants absorve inorganic matter(CO2, H2O, Sunlight) and produce organic matter (glucose, oxygen). Is produced in the clorophila (on cloroplasts). Nutritions: (1) autotrophs (photo and chemo), (2,3) heterotrophs (no photo)In a population relation of feeding: Cannibalism *mothers eat offspringChemoautotrophs: on acuatic volcanos 5km under sea,there were bacteria that do the chemosynthesi (because sunlight doesn't arrive): convert inorganic matter into organic through chemical substances (methane,

1. The Circulatory System

The circulatory system carries substances via the blood, which circulates through the blood vessels and is pumped by the heart.

1.1 Blood

Human blood is a thick, red liquid composed of plasma and blood cells.

Types of Blood Cells:

• Red Blood Cells: Small cells without a nucleus. They are the most numerous in the body and contain iron. This protein helps transport oxygen and carbon dioxide.
• White Blood Cells: Larger and less numerous. They defend our bodies against pathogens and tumor cells.
• Platelets: Are not true cells, but pieces of cytoplasm. They help our bodies to clot.

The Functions of Blood:

• Transport Substances: Transport nutrients and waste substances.
• Regulates Body Temperature: Maintain body temperature by distributing

Understanding Digestion

What is Digestion?

Digestion is the process by which food is transformed into simpler substances (nutrients) so they can be used by our cells. It involves two main processes:

• Mechanical Process: Chewing and the muscular action of organs crush and mix foods with digestive juices.
• Chemical Process: Digestive enzymes in digestive juices cause chemical reactions that break food into simple substances.

Mechanical vs. Chemical Digestion

The digestive system employs both mechanical and chemical digestion:

• Mechanical: Mouth
• Chemical: Stomach, liver, small and large intestine

Swallowing: The Process

Swallowing allows substances to pass from the mouth to the pharynx. It involves three main stages:

1. The bolus is moved to the oral cavity as

Enzymes: Proteins that Function as Biological Catalysts

Puberty begins with the first ejaculation (spermache) and the first menstruation (menarche).

-Menopause (50), andropause (50)

Reproductive Tract

• Epididymis: Formed by the seminiferous tubes, where sperm mature.
• Ductus referens: Continuation of the epididymis and ascends up to the abdomen. It is used to store sperm.
• Urethra: Also part of the urinary tract connecting the bladder to the exterior.

Accessory Glands

• Seminal vesicles: Flow into ductus deferens, secrete spermatic fluid.
• Prostate: Secretes prostatic fluid which consists of substances to protect sperm from the acidity of the vagina.
• Cowper's glands: A pair of glands that secrete a lubricating fluid that facilitates sexual intercourse.

Reproductive Tract

• Fallopian tubes: Two small tubes located

Chemical Evolution