Notes, abstracts, papers, exams and problems of Biology

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hols

Classified in Biology

Written at on English with a size of 857 bytes.

Pollination:

Is the transfer of pollen grains from the

anther to the stigma of a flower

Self-Pollination:

-Pollen transfer takes place between

the anther and stigma of the sames flower

Cross-Pollination:

-Where pollen tranfer takes place between the anther

and the stigma of different flowers of the same plant

or different plant of the same species

-Pollination takes place with the help certain agents

Important

-Pollination is a process flowering plants only undergo.

it is the transfer of pollen to the plant"s stigma. The

process can be done by the plant itself or through

outside agents

First cells and how they obtained energy

Classified in Biology

Written at on English with a size of 1.97 KB.

Active transport is the movement of substances Across cell-membranes against a concentration gradient, from a region of low to A region of high concentration using energy from ATP.

Carrier mediated active transport

Carrier mediated active transport requires both energy (ATP) and the assistance of a transport protein, called pump.

Each pump only transports particular substances, so cells Can control what is absorbed and what is expelled. Pumps work in a specific Direction –the substance can only enter the

pump on one side and can only exit on the other side. Energy Is used to “pump” molecules across cell membranes against their concentration Gradients.

Vesicular active transport

Vesicular active transport is an energy-requiring Mechanism whereby... Continue reading "First cells and how they obtained energy" »

Bioelements and their functions

Classified in Biology

Written at on English with a size of 2.55 KB.

- First of all, all living things have to carry out the three vital functions: nutrition, interaction and reproduction.
-Second, living organisms are made up of similar substances: inorganic (water and minerals) and organic (carbohydrates, lipids, proteins, and nucleic acids). The biomolecules carry out many functions in the organism: to store energy, to form structures, to be part of chemical reactions, and to store the genetic information.
-And third, living things are composed of cells, one or more than one; and there are two types, prokaryotic and eukaryotic.
Levels of organization of living organisms:
subatomic particles - atoms - molecules - biomolecules - organelles - cell - colonies - tissues -organs -  systems - organism.
Types
... Continue reading "Bioelements and their functions" »

Principles of Flight

Classified in Biology

Written at on English with a size of 3.63 KB.

3 cat bacteria- coccus, bacillus and spirillum

3 cat natural selection- directional, disruptive and stabilizing

one advantage of common names and animals- there can be a common name for a certain type of plant or animal or their could be a certain type of plant or animal from a common name

advantage of scientific names of plants and animals- since latin is a dead language, those names will never change.

Carl Linnaeus-Published Species Plantarum in 1753, which is the starting point for naming of plants Published Systema Naturae, 10th edition, in 1758, starting point for naming of animals.

Founder effect- the reduced genetic diversity that results when a population is descended from a small number of colonizing ancestors. It evolves faster.

Linnaeus

... Continue reading "Principles of Flight" »

Trophic breathing

Classified in Biology

Written at on English with a size of 5.37 KB.

Biotic and Abiotic factors:

Ecosystem: all the living and nonliving parts of an environment.

Biotic factors: the living parts of an ecosystem.

Abiotic factors: the nonliving parts of an ecosystem.

Living things need non-living things to survive. Without food, water, and air, living things die. Sunlight (because provides energy that plants, and certain bacteria absorb to make their own food) shelter, and soil are also important for living things

Trees are biotic elements which need water that is an abiotic element. Without water the tree wouldn’t make oxygen, but without trees the water wouldn’t complete the water cycle.

Changes in abiotic factors can result in extreme problems for some organisms. For example, if a plant is adapted to low temperatures

... Continue reading "Trophic breathing" »

level

Classified in Biology

Written at on English with a size of 1.48 KB.

Facial characteristics can be organised into three levels of facial features:

Level 1 details consist of gross facial characteristics that are easily observable. These include general geometry of the face and global skin colour. Such features can be used to quickly discriminate between a short round face and a long thin face, between predominantly male or female characteristics, and between faces from different races.Level 2 details consist of localised face information such as the structure of face components (e.G. Eyes), the relationship between facial components and the precise shape of the face. These features are essential for accurate recognition and require a higher resolution face image. The characteristics of local regions of the face... Continue reading "level" »

Aleosteric site

Classified in Biology

Written at on English with a size of 9.65 KB.

Enzyme

A biomolecule that catalyzes chemical reactions

Absolute Specificity

The characteristic of an enzyme that it acts on one and only one substance

Relative Specificity

The characteristic of an enzyme that it acts on several structurally related substances

Stereochemical Specificity

The characteristic of an enzyme that it is able to distinguish between stereoisomers

Substrate

The substance that undergoes a chemical change catalyzed by an enzyme

Inborn Error of Metabolism

A disease in which a genetic change causes a deficiency of a particular protein, often an enzyme

Cofactor

A nonprotein molecule or ion required by an enzyme for catalytic activity

Coenzyme

An organic molecule required by an enzyme for catalytic activity

Apoenzyme

A catalytically

... Continue reading "Aleosteric site" »

Distogresion dental

Classified in Biology

Written at on English with a size of 1.96 KB.

1) Tertiary crowding theories - lack of tooth wear, 3rd molar pression, late mandibular growth

2) Class II division 2 - MB cusp of U1M is medial to central sulcus of L1M; incr OJ; buccal displaced incisors
3)Increase arch length (therapeutic)- make most of leeway space; distal molar mvt; transversal expansion; incisor protrusion
4) Deep bite therapeutic tx - incisor intrusion; post. Segment extrusion; post. Segment eruption; buccal inclination of upper arches; surgery
5) Van der Linden classification- Type A (too much space); Type B (lack of space); Type C (more lack of space)
6) Class II division 2 - L1M is distal to U1M; UI retroclination; incr OB
7) Explain: 
Failure point- fracture/breaking point
Elastic limit- point in which if we release the
... Continue reading "Distogresion dental" »

Fixism theory

Classified in Biology

Written at on English with a size of 3.47 KB.

Darwin and the theory of natural selection

The principal merit of Darwin's theory, in addition to the many evidence that he provided to it, is the discovery of the mechanism that governs the entire evolutionary process of species: the natural selection.

1) Firstly, when environmental resources become scarce, an inevitable competition occurs and, consequently, begin the struggle for survival in which most individuals die.

2) Secondly, it is also obvious that individuals of the same species have different features or characteristics that appear randomly and make individuals different each other.

 3) Third, these characteristics make some individuals more advantaged than others. Those whose characteristics are favourable to the demands of the environment... Continue reading "Fixism theory" »

dwed

Classified in Biology

Written at on English with a size of 8.87 KB.

PLANT CELLS:

  • Have regular shape

  • Have cell wall, chloroplasts (most of the cells, but not all), a big vacuole

A. Cell Wall:

  • Made of cellulose

  • Only in plant cells

  • Helps to support and protect the cell

  • Fully permeable (even very large molecules are able to go through the cellulose cell wall)

B. Vacuole:

  • It is a space in a cell surrounded by a membrane and contain a solution of sugars and other substances called “cell sap”

  • Full vacuoles press outwards on the rest of the cell and help to keep it in shape

  • (animal cells contain much smaller vacuoles)

C. Chloroplasts:

  • Never found in animal cells

  • Present in Most of the plant cells

  • Contain “Chlorophyll” (absorbs energy from sunlight, and this energy is then used for making food for the plant by “Photosynthesis”

  • Often

... Continue reading "dwed" »