[ Pobierz całość w formacie PDF ]

amino acids The subunits (monomers) from which proteins (polymers) are
assembled. Each amino acid consists of an amino functional group, and a
carboxyl acid group, and differs from other amino acids by the composition of
an R group.
amino acid sequence Also known as the primary structure of a
protein/polypeptide; the sequence of amino acids in a protein/polypeptide
controlled by the sequence of DNA bases.
amniocentesis A method of prenatal testing in which amniotic fluid is
withdrawn from the uterus through a needle. The fluid and the fetal cells it
contains are analyzed to detect biochemical or chromosomal disorders.
amniote egg An egg with compartmentalized sacs (a liquid-filled sac in which
the embryo develops, a food sac, and a waste sac) that allowed vertebrates to
reproduce on land.
amoebocytes Amoeboid cells in sponges that occur in the matrix between the
epidermal and collar cells. They transport nutrients.
amphibians Class of terrestrial vertebrates which lay their eggs (and also mate)
in water but live on land as adults following a juvenile stage where they live in
water and breathe through gills. Amphibians were the first group of land
vertebrates; today they are mostly restricted to moist habitats.
anabolic reactions Reactions in cells in which new chemical bonds are
formed and new molecules are made; generally require energy, involve
reduction, and lead to an increase in atomic order.
anaerobic Refers to organisms that are not dependent on oxygen for respiration.
analogous structures Body parts that serve the same function in different
organisms, but differ in structure and embryological development; e. g., the
wings of insects and birds.
anaphase Phase of mitosis in which the chromosomes begin to separate.
anaphylactic shock See anaphylaxis.
anaphylaxis A severe allergic reaction in which histamine is released into the
circulatory system; occurs upon subsequent exposure to a particular antigen;
also called anaphylactic shock.
androecium Collective term applied to all of the male (stamen) parts of the
flower.
aneuploidy Variation in chromosome number involving one or a small
number of chromosomes; commonly involves the gain or loss of a single
chromosome.
angina Chest pain, especially during physical exertion or emotional stress, that
is caused by gradual blockage of the coronary arteries.
angiosperms Flowering plants. First appearing at least 110 million years ago
from an unknown gymnosperm ancestor, flowering planbts have risen to
dominance in most of the world's floras. The male gametophyte is 2-3 cells
contained within a pollen grain; the female gametophyte is usually eight cells
contained within an ovule which is retaind on the sporophyte phase of the plant's
life cycle.
Animalia Animal Kingdom. Multicellular eukaryotic group characterized by
heterotrophic nutritional mode, usually organ and tissue development, and
motility sometime during the organism's life history.
annuals Plants that grow and reproduce sexually during one year.
antagonistic muscles A pair of muscles that work to produce opposite
effects&emdash;one contracts as the other relaxes: for example, the bicep and
tricep muscles on opposite sides of your upper arm.
anther The top of a stamen's filament; divided into pollen sacs in which the
pollen grains form. |
antibiotics Substances produced by some microorganisms, plants, and
vertebrates that kill or inhibit the growth of bacteria.
antibiotic resistance Tendency of certain bacteria to develop a resistance to
commonly over-used antibiotics.
antibodies Proteins produced by immune system cells that bind to foreign
molecules and microorganisms and inactivate them.
antibody-mediated immunity Immune reaction that protects primarily against
invading viruses and bacteria through antibodies produced by plasma cells; also
known as humoral immunity.
anticodon A sequence of three nucleotides on the transfer RNA molecule that
recognizes and pairs with a specific codon on a messenger RNA molecule; helps
control the sequence of amino acids in a growing polypeptide chain.
antidiuretic hormone (ADH) A hormone produced by the hypothalamus and
released by the pituitary gland that increases the permeability of the renal tubule
of the nephron and thereby increases water reabsorption; also known as
vasopressin.
antigenic determinant The site on an antigen to which an antibody binds,
forming an antigen-antibody complex.
antigens Molecules carried or produced by microorganisms that initiate
antibody production; mostly proteins or proteins combined with polysaccharides.
antinutrients Chemicals produced by plants as a defense mechanism; inhibit
the action of digestive enzymes in insects that attack and attempt to eat the
plants.
anus The posterior opening of the digestive tract.
aorta The artery that carries blood from the left ventricle for distribution
throughout the tissues of the body. The largest diameter and thickest walled
artery in the body.
apical meristem A meristem (embryonic tissue) at the tip of a shoot or root that
is responsible for increasing the plant's length. [ Pobierz całość w formacie PDF ]

zanotowane.pl

doc.pisz.pl

pdf.pisz.pl

razem.keep.pl