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

It used to define the member functions of a class outside

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DESARROLLO INMUNOLOGY 2015

  1. About the killing mechanism of Tc cells (the Kiss of death)

    • How would you define it?

      It is a killing attack deliver by an armed cytotoxic T cell previously sensitize by the same antigen. A single Tc cell can attack many target cells (second amplification of the celular IR), we have to take into account that the contact between cells (during the Kiss of death) is very short in time. This attack ends with the death of infected cells.

    • How many activating signal needs a T cell to be able of delivering the Kiss of death. Explain details for each signal?
      They need 3 signal:
      1o→recognition of the appropiate peptide loaded onto a self HLA- class I molecule.

      2o→co-stimulatory signal delivered by CD28 bound to its ligand on

...
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Plant and Animal Tissues: Reproduction and Types

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Asexual Reproduction in Plants

Asexual reproduction is the process through which an organism produces other organisms without the participation of more than one parent.

Methods of Asexual Reproduction

Runner or Stolon

Runners or stolons can produce buds that develop into new plants that are clones.

Fragmentation

Fragmentation occurs when a small part of the plant falls off onto the soil and begins to grow into a new plant.

Budding

Each bud will grow like a clone of the original plant that produced it, such as a potato.

Gemmation

Gemmae are shed and dispersed to other areas, where they grow to produce new individuals.

Vegetative Propagation

Vegetative propagation happens when someone takes a part of the plant and replants it in another place.

Animal Tissues

Types

...
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Anatomy and Physiology of the Digestive Tract

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The Human Digestive System: Definition and Function

The digestive system is a set of organs responsible for carrying out digestion. It transforms food into simple substances that pass into the blood and eliminates undigested remains. Its primary role is to provide nutrients to cells by digesting food.

Organs of the Digestive System

Mouth

  • Lips: Fleshy muscles that surround the mouth.
  • Palate: The roof of the mouth, separating the mouth and nostrils. The anterior part is the hard palate, and the posterior part is the soft palate.
  • Uvula: A structure that hangs from the soft palate, preventing the passage of substances into the nostrils.
  • Teeth: Used to crush food. Types include incisors, canines, premolars, and molars. Adults typically have 32 teeth (8
...
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Guide to Healthy Eating: Nutrients, Functions, and Tips

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Healthy Eating Plate

  • Oils:

    Olive oil for cooking, on salad, and at the table. Limit butter, avoid trans fat.
  • Water:

    Drink water, tea, or coffee with little or no sugar. Limit milk (1-2 servings a day) and juice (1 small glass a day). Avoid sugary drinks.
  • Vegetables:

    The more veggies and variety, the better. Potatoes and French fries don't count.
  • Whole Grains:

    Eat a variety of whole grains like whole-wheat bread, whole-grain pasta, and brown rice. Limit refined grains like white rice and white bread.
  • Fruits:

    Eat plenty of fruits of all colors.
  • Healthy Protein:

    Choose fish, poultry, beans, and nuts; limit red meat and cheese; avoid bacon, cold cuts, and other processed meats.

Foods and Nutrients

The difference between food and nutrients is that nutrients...

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Functions of Cell Organelles

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Nucleus:

Converts genetic material, controls all the cell, and contains nucleolus.

Mitochondria:

Converts solar energy in food to usable compounds.

Chloroplast:

Converts solar energy to chemical energy stored in food.

Cytoskeleton:

Maintains cell shape and helps cell move.

Ribosomes:

Synthesize proteins.

Endoplasmic Reticulum:

Assembles proteins and lipids.

Vacuoles and Vesicles:

Store materials.

Centrioles:

Organize cell division.

Cell Membrane:

Regulates materials that enter and leave the cells.

Golgi Apparatus:

Packages proteins and lipids for storage or transport out of the cell.

Cell Wall:

Shapes, supports, and protects cell.

Lysosomes:

Break down and recycle macromolecules.

Cytoplasm:

Gel-like mixture, surrounded by cell membrane, contains hereditary...

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Debunking Common Myths About Evolution

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Myth 1: Everything is an Adaptation Produced by Natural Selection

We tend to assume that all characteristics of plants and animals are adaptations that have arisen through natural selection. Many are neither adaptations nor the result of selection at all.

Argument 1: Not everything is an adaptation

→ Male nipples

Argument 2: Multi-Skilled Genes

We have multi-skilled genes which have more than one function.

Myth 2: Natural Selection Is the Only Means of Evolution

Before we were told all of the 10 facts were myths, we already thought this was not right, because science can also change evolution with the advanced technology we have nowadays.

Myth 3: Evolution Leads to Ever-Greater Complexity

→ No -. Evolution gets rid of what we don’t use (example:...

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An Introduction to Human Anatomy and Physiology

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What is Cytology?

Cytology is the study of the internal structure and function of individual cells.

What is Histology?

Histology is the study of the microscopic structure of tissues.

What is Anatomy?

Anatomy is the study of the structure and relationship between body parts. There are several sub-disciplines within anatomy:

Surface Anatomy

Surface anatomy is the study of the external features of the body.

Regional Anatomy

Regional anatomy is the study of anatomy based on regions of the body. It involves the study of the superficial and internal features in a specific area of the body.

Pathological Anatomy

Pathological anatomy is the medical specialty concerned with the diagnosis of disease based on the gross and microscopic examination of tissues.

What

...
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DNA and Genetic Engineering: A Comprehensive Overview

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DNA is the molecule that gives cells and organisms their biological characteristics. Types of Nucleotides: Adenine, Cytosine, Thymine, Guanine. DNA/RNA: DNA has a double helix structure, while RNA does not. In DNA, thymine is present, whereas in RNA, uracil is present. RNA can exit the nucleus, but DNA cannot. Ribose Nucleotide does not contain thymine. Transcription is the process of copying a part of the genetic message from DNA to RNA. Translation is the process in which RNA moves from the nucleus to the cytoplasm. Genetic Code refers to the relationship between the sequence of nitrogenous bases in DNA and the sequences of amino acids that form proteins. Transcription occurs in the nucleus, while translation occurs in the cytoplasm. In prokaryotic...

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Understanding Health, Diseases, and the Immune System

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Twins and Multiple Births

Twins originate from the same egg and sperm that then divides into two embryos. These embryos share the same genetic material. On the other hand, fraternal twins develop from two separate eggs and two sperm cells. Genetically, they are like siblings but born at the same time.

Puberty

Puberty is the life stage where a person develops secondary sexual characteristics and achieves reproductive capability. It's the initial phase of adolescence, marking the transition from childhood to adulthood.

Diseases and Health

Causes of Diseases

Degenerative diseases involve the progressive destruction of tissues. Affected organs gradually deteriorate, as seen in Alzheimer's disease.

Health

Health is a state of complete physical, mental,...

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The Origin and Evolution of Life

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Spontaneous Generation

The idea that life can appear from inanimate objects is known as spontaneous generation.

  • In Ancient Egypt, people believed that the Sun's heat created life.
  • During the Middle Ages, people created recipes to generate living things from materials.
  • In the 17th century, scientists proved that spontaneous generation was not possible.
    • In 1668, Redi demonstrated that larvae found in rotten meat came from fly eggs.
    • In the 19th century, Pasteur demonstrated that microorganisms did not come from spontaneous generation, and this theory was finally rejected.

Origin of Life

Chemical Evolution

Chemical evolution is the process that formed the molecules that make up living things and their organization into membranes.

  1. The first biomolecules to
...
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