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A body is placed in a certain airstream

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Non-s defences act against any type of microorganism. Is carried out by phagocytes: white blood cells that eliminate microorganisms. This process is phagocytosis./Inflammatory response is a non-s defence. When pathogens get through the external barriers, the blood cells  increase the blood flow. This help the transport of phagocytes towards the infected area. Inflammation occurs in the connective tissues with many blood capillaries. Large numbers of phagocytes destroy the pathogens. The remains are pus/Specific defences. When a non-specific response doesn’t stop a pathogen, there is: a specific immune response. Is carried out by lymphocytes, a type of white blood cells./Lymphocytes recognize antigens entering the body. The lymphocytes are
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Understanding HIV and AIDS: Immune System Impact

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Understanding HIV and AIDS: Impact on the Immune System

In 1981, a rare form of pneumonia, caused by a protozoan, was observed. Medical investigators noticed a relationship between this pneumonia and a rare form of skin cancer. Both the pneumonia and the skin cancer seemed to be associated with a widespread failure of the body's immune system.

The Discovery of HIV

By 1983, the pathogen responsible for this immune system disease had been identified. It is a retrovirus. The disease is now known as Human Immunodeficiency Virus (HIV). HIV specifically targets and kills helper T cells in the body, which are crucial for immune function. The progression of HIV infection ultimately leads to Acquired Immune Deficiency Syndrome (AIDS).

How HIV is Transmitted

HIV

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Human Nervous System: Central and Peripheral Divisions

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The Human Nervous System: Divisions and Functions

The human nervous system is a complex network responsible for controlling all body activities. It is broadly divided into two main parts:

  • Central Nervous System (CNS): Protected by bones (skull and spine) and three membranes called meninges.
  • Peripheral Nervous System (PNS): Composed of nerves that connect receptors and effectors to the central nervous system.

Central Nervous System (CNS)

The Central Nervous System (CNS) is the body's control center, formed by the brain (located inside the skull) and the spinal cord (located inside the spine).

The Brain: Control Center of the Body

The brain is the most complex organ in the human body, responsible for thought, emotion, memory, and movement. It comprises... Continue reading "Human Nervous System: Central and Peripheral Divisions" »

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JHH-7 doubling time

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__________ 1. In sexual reproduction of fungi, spores are produce By mitosis.

__________ 2.Yeast is a rapidly growing, asexually reproducing Stage of some types of fungi.

__________ 3.Fungi form mutualistic symbiotic associations with Other organism.

__________ 4.Fungi play important ecological roles by decomposing Organic matter and by

breaking down and absorbing minerals From rocks and soil.

__________ 6.All fungi are helpful.

__________ 7.Plants are multicellular eukaryotes whose cells have cell membrane made of

cellulose.

__________ 8.Reproduction in seed plants is characterized by a Greatly reduced gametophyte

and a dominant sporophyte.

__________ 9. The flowers of many gymnosperms are adapted for Pollination by wind or by

animals.

__________ 10.Although... Continue reading "JHH-7 doubling time" »

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Human Biology: Immune System, Reproduction, and Cardiovascular Health

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Vaccines and the Immune System

1. Vaccines introduce weakened or dead pathogens to stimulate the immune system. This prepares the body to fight future invasions by these microbes.

Vasectomy: Blocking Sperm Transport

2. In a vasectomy, the structure that is closed or blocked to prevent sperm from traveling from the testes to the urethra is the vas deferens.

Non-Specific Immune Responses

3. Sweat and skin secretions kill or limit the growth of many types of microbes. This control of microbes is an example of a non-specific immune response against infection.

The Amniotic Sac in Pregnancy

4. The fluid-filled structure in which the embryo is protected during pregnancy is called the amniotic sac.

Opportunistic Infections

5. Pathogens that cause opportunistic

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Human Skeletal System: Joints, Skull Foramina, and Thorax

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Human Skeletal System: Key Structures and Functions

Types of Synovial Joints

  • Plane Joints

    Characterized by flat surfaces on one bone meeting with flat surfaces of another, allowing for slipping and gliding movement with no axial rotation. Common examples include the carpal bones of the wrist.

  • Hinge Joints

    A cylindrical projection of one bone fits into a trough-shaped surface of another bone. These joints permit flexion and extension, like the elbow joint (specifically, the olecranon process of the ulna).

  • Pivot Joints

    A rounded projection of one bone fits into a rounded depression or sleeve of another bone, often held together by ligaments. They allow for uniaxial movement, such as the rotation of the odontoid process of C2 (axis) within the anterior

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Human Reproduction: Characteristics, Process, and Systems

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Characteristics of Sexual Reproduction

Human reproduction is sexual. This means that it's necessary for two individuals of different sexes to take part.

  1. Each sex produces a different type of sex cell or gamete.
  2. Fertilization is internal; it takes place inside the female reproductive system.
  3. We are viviparous; the fetus grows in the mother's womb.
  4. We are sexually dimorphic. This means that males and females have physical differences. This happens in many species.

Process of Reproduction

  1. Gametogenesis: formation of the gametes.
  2. Fertilization: joining of the male and female gametes.
  3. Embryo Development: cell division and differentiation.
  4. Childbirth: birth of the baby.
  5. Development: cells increase and mature.

Changes in Adolescence

Adolescence begins with puberty,... Continue reading "Human Reproduction: Characteristics, Process, and Systems" »

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Cell Division, Chromosomes, and Cell Differentiation

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Main Reasons Why Cell Divides

  • Larger cell demands more place for the DNA.
  • Larger cells result in less moving nutrients and waste materials across the cell membrane.

Information Overload

Cell grows, information is used to build the molecules needed for cell growth. DNA doesn't increase.

Exchanging Materials

Food, oxygen, water enter by the cell membrane, waste products also go out like that.

Division of the Cell

Forms 2 daughter cells. Cell division: process in which a cell divides into 2 daughter cells.

Asexual Reproduction

1 parent, cell divides by fission, little chances of genetic variation, found in bacteria, 2 offspring.

Sexual Reproduction

2 parents, cell divides by meiosis, genetic variation, found in mammals, 1 offspring.

Both

Forms of reproduction,... Continue reading "Cell Division, Chromosomes, and Cell Differentiation" »

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Galapagos Finches Evolution: Adaptation and Speciation

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Galapagos Finches: Adaptation and Speciation

The Galapagos Finches originated from a single common ancestor. This initial population diversified, leading to various species adapting to different lifestyles. Adaptation, an evolutionary process, enhances a species' survival and reproductive success in a specific environment.

Environmental Influence on Finch Evolution

Environmental changes compelled the finches to adapt to varying diets, climates, and other factors. The finches' beaks were crucial in determining their diet. Initially, the finches utilized resource partitioning based on their beak sizes. Finches with smaller beaks consumed small seeds, while those with larger beaks ate larger seeds.

The Impact of Drought and El Niño

During a drought,

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Endocrine System and Hormone Regulation: A Comprehensive Guide

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Endocrine System

The endocrine system coordinates body processes using chemical messengers called hormones.

Functions of Hormones:

  • Control cell metabolism
  • Maintain the body's internal stability (homeostasis)
  • Regulate growth, sexual development, and reproduction

Endocrine Glands

Endocrine glands produce and release hormones, which the bloodstream distributes throughout the body to all cells.

Hormone Regulation

The endocrine glands and circulatory system work together to regulate hormones. For example, the pancreas secretes insulin when it detects excess glucose in the blood. Insulin causes muscle cells and liver cells to absorb glucose from the bloodstream.

Nervous System Coordination

The nervous system coordinates the activity of endocrine glands through... Continue reading "Endocrine System and Hormone Regulation: A Comprehensive Guide" »

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