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

white blood cells           red blood cells              platelets

Blood Composition and Functions

Cells live immersed in a medium that provides them with all the nutrients they need. They also secrete the waste products released during metabolism into this medium. In multicellular organisms like humans, this medium is called the internal milieu and is made up of the interstitial plasma, a fluid found in the space between the cells. The interstitial plasma is renewed thanks to the blood, which continuously circulates around the whole body, providing nutrients and taking away waste products.

What is Blood?

Blood is a viscous fluid with a salty taste that flows inside the vessels that make up the circulatory system.

Blood Components

Blood is made up of cells suspended in a liquid called blood plasma.

• Blood plasma

What is Animal Cloning?

Cloning is the process by which we obtain an identical copy, or clone, from the genetic point of view of any living entity, such as a cell or an organism.

How Do You Clone an Animal?

The first time that clone cells were obtained from an adult animal was in 1996. As a result, the sheep Dolly was born, the first mammal cloned in history. The technique used is called nuclear transfer.

Stages of Animal Cloning

1. A differentiated cell is taken from the individual that is to be cloned. These cells contain the entire genome of the organism, with the difference that it is a specialized cell that has lost the ability to reproduce.
2. An egg is taken from a female donor.
3. The egg nucleus is removed.
4. The nucleus of the differentiated cell is

Environmental Factors

Characteristics of the environment that affect living things are called environmental factors. They can be abiotic (related to non-living things) or biotic (related to living things).

Biotic and abiotic factors

⦁ Abiotic factors: Physical and chemical conditions that affect living things.

The main abiotic factors are water, light, temperature, soil, pH, humidity, and nutrients found in water and soil. Some abiotic factors are more important than others depending on the location they are in.

• Sunlight is essential for life on Earth to exist.
• The concentration of oxygen in the atmosphere decreases as altitude increases.
• Temperature is a decisive factor in the physiological activity of living things.
• Water is an essential substance

Digestive System Diseases

Oral Cavity

• Tooth Decay

  Tooth enamel is destroyed by acids produced by bacteria that break down food fragments stuck between teeth. Tooth decay causes cavities to form, and bacteria in the cavities can then destroy the teeth.

• Gingivitis

  Inflammation of the gums caused by vitamin deficiencies or poor dental hygiene.

Stomach

• Gastroenteritis

  An infection affecting the stomach or intestine, caused by bacterial toxins. Symptoms include diarrhea, vomiting, abdominal pain, and fever.

• Gastritis

  Irritation of the gastric mucosa causing pain, acidity, and a burning sensation. Often caused by smoking, drinking alcohol, eating spicy foods, or taking medicine.

• Stomach Ulcer

  Damage to the gastric mucosa which causes the stomach cavity to come

FUNGI KINGDOM

Cellular Organization:

Unicellular or multicellular, the cells are eukaryotic, they have no tissues.

Size and Shape:

Unicellular fungi, like yeast, are round or oval and microscopic in size.

Nutrition:

Heterotrophic, many are saprophytes, feeding on organic material from animals or plants.

Lifestyle:

They can be free-living symbionts or parasites.

Reproduction:

Unicellular asexual, multicellular asexual, or sexual.

PROTOCTIST KINGDOM PROTOZOA

Cellular Organization:

Unicellular, they have no tissues.

Size and Shape:

Oval, round, oblong, half-moon. All are microscopic.

Nutrition:

Heterotrophic, feeding on bacteria and algae.

Habitat and Lifestyle:

Most are free-living.

Reproduction:

They reproduce asexually by binary fission.

Movement:

They move by using...

Invertebrate Reproduction

Porifera (Sponges)

They perform both types of reproduction:

• Asexual Reproduction: A small piece of sponge breaks off, anchors to a surface, and regenerates into a complete organism.
• Sexual Reproduction: This requires two individuals of opposite sex. They form sexual cells (sperm and ovum) that join together and produce a larva. The larva then anchors to a surface and grows, forming a new individual.

Polyps

They reproduce both asexually and sexually:

• Asexual Reproduction: A small bud forms and remains attached as it grows. It separates from the parent organism only when mature and then anchors to a surface.
• Sexual Reproduction: This requires two individuals of opposite sex. They form sexual cells (sperm and ovum) that join

Internal Environment

Internal environment refers to the fluids that surround the cells in the body. This stable internal environment, called homeostasis, is maintained by the organ systems of the body.

The Circulatory System

The circulatory system consists of the blood circulatory system. It carries nutrients and oxygen throughout the body and collects metabolic wastes for elimination. The lymphatic system has three main functions: transport absorbed fat from the fat, defend the body in the immune system, and return excess interstitial fluid to the blood.

Blood

Blood is a thick red liquid that flows inside the blood vessels. Blood's plasma consists of water and dissolved substances. Blood cells, red and white blood cells, and platelets make up the...

Heart Anatomy and Function

Chambers and Valves

The heart is a muscular, hollow organ divided into four chambers:

• Upper Chambers (Atria): Left atrium and right atrium.
• Lower Chambers (Ventricles): Left ventricle and right ventricle.

Between the atrium and ventricle, the atrioventricular valve allows blood flow from the atrium to the ventricle but prevents backflow. The valve between the left atrium and ventricle is bicuspid, while the valve between the right atrium and ventricle is tricuspid.

Blood Circulation

Cardiac Cycle

• Atrial Systole: Atria contract, pumping blood into the ventricles through open atrioventricular valves.
• Ventricular Systole: Ventricles contract, sigmoid valves open, and blood flows into the pulmonary artery and aorta. Atrioventricular