Plant Biology: Vascular Plants, Angiosperms, Gymnosperms, and More

Vascular Plants

Vascular plants are those that have a system of vessels inside that allow the movement of substances and nutrients throughout the plant. Two examples of vascular plants are ferns and Ficcus, a woody plant with no flowers. There are also vascular plants with flowers such as sunflowers, and there are woody plants such as apricot that have a vascular system, yet also have flowers in a process of reproduction.

Angiosperms and Gymnosperms

Angiosperms have covered seeds by fruit (orange, apple, etc.) and the gymnosperms have naked seeds, that means outside the plant (pine).

Differentiate between Dicotyledons and Monocotyledons

  • Dicotyledons:
    • 2 cotyledons
    • Leaf veins are arranged according to a reticular pattern
    • Stem vascular bundles are arranged in a radial pattern like spokes of a wheel
    • There are approximately 170,000 species
  • Monocotyledons:
    • 1 cotyledon
    • Veins are arranged parallel relative to each other
    • Vascular bundles are randomly scattered around the stem
    • There are about 50,000 species

Meristematic Tissue Function

The meristematic tissue in plants plays a role in growing the plant due to its main feature of cell division (mitosis), as all other tissues.

Role of Xylem and Phloem

  • Xylem: Transports minerals dissolved in water to the leaves, where by means of photosynthesis, these elements are transformed into nutrients.
  • Phloem: The fabric that “collects” the nutrients already formed and distributed throughout the body plant for their own food and/or reservation.

Modifications of Leaves

  • Shape: (acicular, rhombic, ovate)
  • Margin: (crenate, dentate, spinous)
  • Venation: (open, closed, parallel)


Protect the growing tissue and open the way to the root through the soil, thereby facilitating their development.

Sexual Reproduction with Flowers

  • Pollination: First, the pollen grain has to come into contact with a structure, usually known as sticky stigma. Then, the pollen grain develops a pollen tube which grows through the style to reach the egg.
  • Fertilization takes place when the male gamete contact with the egg. In the ovary are the eggs that contains eggs that are fertilized by one of the nuclei of the pollen grain. After fertilization occurs the seeds are formed. The seed contains the embryo that then produce a new individual.

Factors Influencing Movement of Water and Minerals from Plants

Water enters the plant from the soil by the roots. The movement of water into the root cells is only possible when water potential in soil water potential is higher than in roots. The essential elements are incorporated from mineral soil within the root cells through the activity of specific transporters, and are transported to the stem, after being poured into the xylem, along with the transpiration stream. They perform a variety of functions in plants, some of which are not specific, for example, the effects they have on the osmotic potential. Other features are specific, as the presence of magnesium in the molecule of chlorophyll.

Plant Hormones and Their Role

  • Auxin: Regulation of growth and development of plants. Whether they are synthetic and natural are responsible for: dominance of the main shoot and lateral inhibition, stimulation of growth of all plants, inhibition of falling leaves and fruits.
  • Toquininas Ci has the opposite effects to those of auxin-Stops the falling leaves. promotes the development of outbreaks. retard aging of the organs of the plant.
  • Gibberellins: Stem elongation occur at the end, stimulate the production of flowers and fruit and seed germination.
  • Abscissa acid (ABA) Their actions are contrary to the gibberellins x that is considered an inhibitor of seed germination and development of buds and also inhibits the growth of the plant.
  • Ethylene. It is the only gaseous plant hormone at room temperature has the following functions: it inhibits the growth of the planta.favorece separation of stem and leaf drop and fruit (ADCISIS process.) accelerates the ripening of fruits. (Ripening, ethylene-rich environments).

Circadian Rhythms

The rhythms that continue with a period close to 24 hours even when all environmental conditions remain constant and are called circadian rhythms have been found in all organisms eukaryotic and some prokaryotic. Circadian rhythms are endogenous, or That is, they originate inside the body and are controlled by what is called biological clock.


The state of dynamic equilibrium or set of mechanisms by which all living things tend to achieve stability in the properties of its internal environment.

Respiratory System

In physiology is called pulmonary ventilation set of processes that make the air flow between the atmosphere and the alveoli through alternating acts of inspiration and expiration. The factors involved in this mechanism are internal airways, the diaphragm, thoracic cavity formed by the vertebral column, the sternum and ribs and associated musculature. Ventilation is carried out by muscles that change the volume of the chest cavity, and in doing so create negative and positive move air in and out of the lungs.

Respiratory System Function

  • Add oxygen to the body for reaching the fuel cell to produce the nutrients and release energy.
  • Waste such as carbon dioxide is expelled through the process of exhalation.


The process by which blood is oxygenated in the lungs. This occurs by the exchange between the oxygen that enters the inspiration, and the CO2 that comes with each expiration. The oxygen enters the blood and carbon dioxide exits

Figurative Elements in the Blood

  • Red blood cells
  • White cells
  • Platelets

Blood Plasma

Its main component is water. It also contains plasma proteins, inorganic substances (such as sodium, potassium, calcium chloride, carbonate and bicarbonate), sugars, hormones, enzymes, lipids, amino acids and degradation products such as urea and creatinine. All these substances are in small quantities.

Heart Anatomy

The heart is composed of: right atrium, left atrium, superior vena cava, aorta, pulmonary arteries, left and the right pulmonary veins, mitral valve, aortic valve, left ventricle, right ventricle, inferior vena cava, tricuspid valve, pulmonary valve, greater and lesser circulation