Biology Nmat new set

BIOLOGY 2 Definition of Terms:     

Plant Morphology – refers to the study of the plant structure Plant Anatomy – is the phase of morphology dealing with the minute internal structure of plants, with special reference to their tissue Plant physiology – is the study of chemicals, physical processes and behavior of plants Plant genetics – is the study of inheritance and breeding of plants Plant pathology – is the study of the causes, control and other features of plant diseases

What Distinguishes Most Plants from Animals      

Most plants are able to manufacture their own foods from raw materials from the air and soil, while animals lack this ability and depend upon plants for their food Most plants have green pigments chlorophylls which are lacking in most animals Most plants contain cellulose in their structural framework, a substance lacking in all but a few species of animals Most plants are stationary, whereas most animals are capable of locomotion Most plants have an unlimited scheme of growth, as contrasted with the limit scheme of most animals Most plants produce spores, non sexual reproductive cells, which are generally lacking in animals

Main Organ of Plants Roots      

Absorption of water and dissolved materials The anchorage of plant The conduction of water and dissolved substance from the root up into the stems and of food from the stem down to the root The storage of food and water Reproduction Photosynthesis in a few species

Stem     

The conduction of materials from roots to leaves and from leaves to roots The storage of foods and other substances The production and support of leaves and flowers or cones Reproduction Photosynthesis

Leaves 

Chiefly in manufacture of foods from water and mineral salts absorbed from the soil and from the carbon dioxide of the air

Cones and Flowers 

For reproduction

Why water is Important to Plants      

It is a constituent of living protoplasm It is a raw material used in food manufacture It is the medium of absorption and of transportation of solid materials in plants It is the medium in which most of the chemical reactions in protoplasm takes place. It provides the pressure which if necessary for the maintenance of form, for support of the growth It helps regulate temperature

Important Plant Processes     

Imbibition – process entails the absorption of water by deep or partly dry colloidal materials Osmosis – diffusion of a liquid thorugh a differentially permeable membrane Diffusion – the tendency of the molecules of a substance to move from a region of greater abundance to a region of lesser abundance Plasmolysis – outward diffusion of water causes a shrinkage of the protoplasm away from the cell wall Osmotic pressure – the maximum pressure which water by a rigid membrane permeable only to water

Specialized Roots     

Aerial roots – ivy Prop roots – corn Storage roots – carrots Contractile roots – bulbs and other underground stems Photosynthetic roots – orchids

Difference of Herbaceous Stems and Woody Stems Herbaceous Stems  Soft and green  Little growth in diameter  Tissue chiefly primary  Chiefly annual

Woody Stems  Tough and not green  Considerable growth in diameter  Tissue chiefly secondary  Chiefly perennial

 Covered by an epidermis  Buds mostly naked Difference of Photosynthesis and Respiration Photosynthesis  Takes in carbon dioxide  Released oxygen  Synthesized sugars and other organic compounds  Result in increase in dry weight  Occurs only in the presence of chlorophyll  Stores energy  Occurs only when light energy is available

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Covered by corky bark Buds chiefly covered by scales

Respiration  Release carbon dioxide  Binds oxygen  Degrades sugar and other organic compounds  Results in decrease in dry weight  Occurs in all living cells  Release energy  Occur throughout entire life of any cell

Zoology Important Terms and Definitions          

Zoology – is the study of animals Biology – zoology and botany together Cystology – study of cells Hypothesis – the scientist analysis available date and from these develops a “scientific guess” as to the cause of the observed phenomenon Theory – application of hypothesis Scientific law – when the theory proves to have a wide application Ecology – the study of relations between organism and environment Genetics - the study of the similarities and differences existing between parents and offsprings, and the factors which control the same Is the term applied to the progressive development of more complex forms of life from simpler one Embryology – is the study of development

Chemicals and Elements that are most characteristics of protoplasm 

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Elements: Hydrogen, carbon, nitrogen, oxygen, phosphorus, sulphur o Sodium, magnesium, chlorine, potassium, calcium, iron – usually present but not invariably Compounds o Carbohydrates o Lipids o Protein o Nucleic acids o Hormones and vitamins

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o Enzymes o Inorganic constituents Biological Characteristics of protoplasm o Metabolism  Digestion  Respiration  Assimilation o Growth o Irritability o Organization

Cells    

Minute protoplasm exists in the form of masses, consist of a central differentiated portion. The nucleus and a surrounding portion, the cytosome. Cell membrane – the outside boundary of all cells is determined by a thin but definite membrane Cytosome – is the part of the cell lying outside the nucleus Nucleus – is a specialized mass of protoplasm usually spherical, near the center of the cell

Major Characteristics of a typical Cell  

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Cell membrane Cytosome o Cytoplasm –fills most of the space between nucleus and cell membrane o Vacuoles – are relatively large liquid globules suspended in the cytoplasm o Central bodies – they are division centers from which radiate during cell divisions, cytoplasmic strands o Mitochondria - are granules of small size but of various shape suspended in the cytoplasm. They are the centers of enzyme activity o Golgi – apparatus o Plastids – centers of chemical activity Nucleus o Is a protoplasmic membrane surrounding the nucleus, similar in constitution to the cell membrane o Nucleosome – consist of everything enclosed by the nuclear membrane

Mitosis  

Indirect cell division Phases or Steps o Prophase – all the changes in the cell from the beginning of division to the establishment of the chromosome on the equator of the spindle

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Metaphase - the division and separation of the daughter chromosome on the spindle Anaphase – the changes associated with the migration of chromosome to the poles of the spindle, the position of the new nuclei o Telophase – the processes of reorganization of the 2 daughter cells Amitosis – is a direct nuclear division, the nucleus fragmenting or pinching in 2, usually not followed by division of the cytosomes

Meiosis 

is a special type of cell divisionnecessary for sexual reproduction in eukaryotes. The cells produced by meiosis are gametes or spores.

Interphase 

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Growth 1 (G1) phase - G1 stage each of the chromosomes consists of a single (very long) molecule of DNA. In humans, at this point cells are 46 chromosomes, 2N, identical to somatic cells Synthesis (S) phase - The genetic material is replicated: each of its chromosomes duplicates, so that each of the 46 chromosomes becomes a complex of two identical sister chromatids. The cell is still considered diploid because it still contains the same number of centromeres. The identical sister chromatids have not yet condensed into the densely packaged chromosomes visible with the light microscope. This will take place during prophase I in meiosis Growth 2 (G2) phase- G2 phase as seen before mitosis is not present in Meiosis. Actually, the first four stages of prophase I in many respects correspond to the G2 phase of mitotic cell cycle.

Meiosis I 

consists of separating the pairs of homologous chromosome; each made up of two sister chromatids, into two cells.

Meiosis II 

consists of decoupling each chromosome's sister strands (chromatids), and segregating the individual chromatids into haploid daughter cells. The two cells resulting from meiosis I divide during meiosis II, creating 4 haploid daughter cells. Meiosis I and II are each divided into prophase, metaphase, anaphase, and telophase stages, similar in purpose to their analogous subphases in the mitotic cell cycle.

EVOLUTION Heredity 

Genotype - Inherited traits are controlled by genes and the complete set of genes within an organism's genome

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Phenotype - The complete set of observable traits that make up the structure and behaviour of an organism

Variation 

Hardy-Weinberg principle - provides the solution to how variation is maintained in a population with Mendelian inheritance. The frequencies of alleles (variations in a gene) will remain constant in the absence of selection, mutation, migration and genetic drift.

Gene Flow 

is the exchange of genes between populations and between species. It can therefore be a source of variation that is new to a population or to a species.

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can be caused by the movement of individuals between separate populations of organisms, as might be caused by the movement of mice between inland and coastal populations, or the movement of pollen between heavy metal tolerant and heavy metal sensitive populations of grasses.

Natural Selection 

is the process by which genetic mutations that enhance reproduction become and remain, more common in successive generations of a population.

ECOLOGY Biomes - are climatically and geographically defined as similar climatic conditions on the Earth, such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems. A fundamental classification of biomes is:  

Terrestrial (land) biomes Aquatic biomes (including freshwater biomes and marine biomes)

8 Classification of Biomes        

tundra taiga temperate deciduous forest scrub forest (called chaparral in California) grassland desert tropical rain forest temperate rain forest

Tropical Rainforest  

The trees are very tall and of a great variety of species. One rarely finds two trees of the same species growing close to one another.

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The vegetation is so dense that little light reaches the forest floor. Most of the plants are evergreen, not deciduous. The branches of the trees are festooned with vines and epiphytes (see the photo taken in the Luquillo National Forest of Puerto Rico). Epiphytes are plants that live perched on sturdier plants. They do not take nourishment from their host as parasitic plants do. Because their roots do not reach the ground, they depend on the air to bring them moisture and inorganic nutrients. Many orchids and many bromeliads (members of the pineapple family like "Spanish moss") are epiphytes.

Temperate Deciduous Forest      

hardwood trees (e.g., beech, maple, oak, hickory) which are deciduous; that is, shed their leaves in the autumn. The number of different species is far more limited than in the jungle. Large stands dominated by a single species are common. Deer, raccoons, and salamanders are characteristic inhabitants. During the growing season, this biome can be quite productive in both natural and agricultural ecosystems.

Taiga  

The taiga is named after the biome in Russia. It is a land dominated by conifers, especially spruces and firs.

Tundra  

The climate is so cold in winter that even the long days of summer are unable to thaw the permafrost beneath the surface layers of soil. Sphagnum moss, a wide variety of lichens, and some grasses and fast-growing annuals dominate the landscape during the short growing season.

Chaparral 

The annual rainfall in the chaparral biome may reach 20–30 inches (64–76 cm), but in contrast to the grasslands, almost all of this falls in winter. Summers are very dry and all the plants — trees, shrubs, and grasses — are more or less dormant then.

Marine Ecosystem 

All life in the ocean is divided into three main groups. o Plankton o Nekton o Benthos

Freshwater Ecosystem

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Freshwater ecosystems can be divided into lentic ecosystems (still water) and lotic ecosystems (flowing water). Limnology (and its branch freshwater biology) is a study about freshwater ecosystems.

ECOLOGICAL SUCCESSION  

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Is the phenomenon or process by which an ecological community undergoes more or less orderly and predictable changes following disturbance or initial colonization of new habitat Primary Succession - is one of two types of biological and ecological succession of plant life, occurring in an environment in which new substrate devoid of vegetation and usually lacking soil, such as a lava flow or area left from retreated glacier, is deposited. In other words, it is the gradual growth of an ecosystem over a longer period. Secondary Succession - occurs on substrate that previously supported vegetation before an ecological disturbance from smaller things like floods, hurricanes, tornadoes, and volcanic eruptions which destroyed the plant life. Community Founds in a Climax Community o

Hydrosere - Community in freshwater

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Lithosere - Community on rock

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Psammosere - Community on sand

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Xerosere - Community in dry area

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Halosere - Community in saline body (e.g. a marsh)