Summary of common experimental methods of biology

(1) Determine the presence of a substance based on color:
Starch + I2 (blue); reducing sugar + Feilin reagent (brick red); fat + Sudan III (orange) or + Sudan IV (red); protein + biuret reagent (purple);
Escherichia coli + eosin and methylene blue (colonies are dark purple with metallic luster) (2) Color differentiation is used to determine the differentiation of the three germ layers of the gastrula. (3), using fluorescent labeling to prove that the cell membrane has a certain mobility
(4) Isotope tracer method: source of oxygen produced by photosynthesis; destination of carbon dioxide in photosynthesis;
The phage-infected bacteria experiment proves that DNA is a genetic material, and protein is not a genetic material;
DNA replication is a semi-reserved replication. (5) Method for determining that an element is an essential element for plant growth: Hydroponics (Complete culture solution is compared with complete culture medium of deficiency) (6) Method for obtaining seedless fruit:

Treat the ovary of the flower bud stage with the appropriate concentration of auxin, such as seedless tomatoes,
Inducing chromosomal variation, such as seedless watermelon.
(7), methods to determine a certain hormone function:
Feeding method, excision injection method, castration transplantation method, and excision oral method. (8), to determine the function of incoming and outgoing nerves:
Stimulation + observation of the effector response or measurement of potential changes on the nerve.
(9), method of plant hybridization
Androgynous flower: flower bud period to male + bag + flowering artificial pollination + bagging
Male and female flowers: flower bud stage female flower bagging + flowering stage artificial pollination + bagging (10), method for determining the genotype of a dominant individual:
Test cross; the dominant individual is self-interested.
(11) A method for determining whether a trait is a dominant trait or a recessive trait: Hybridization of a homozygous pair having a relative trait, self-crossing, and observing whether the progeny has a trait separation.
(12) Method for determining whether an individual has a resistance gene: Determine whether the wheat has a rust-resistant gene, and infect it with a rust bacterium, and observe the presence or absence of rust spots after a period of time. (13), method of identifying blood type:
The blood serum was observed under a microscope by mixing the standard serum with the blood type to be tested.
(14), breeding methods:
Cross breeding; artificial mutation breeding; single sports species; genetic engineering breeding; cell engineering breeding; multiple sports species.
(15) Method for determining population density: sample method; mark recapture method (16), method for making ecological bottle; bottle must be transparent and closed (17), method for separating microorganisms:
Plate scribe method; culture in selective medium (eg separation of round nitrogen-fixing bacteria, isolation of Staphylococcus aureus, separation of bacteria and yeast) (18), method for determining growth of microorganism population:
Determination of the number of bacteria - microscopic counting
Determine the weight of the bacteria--take a certain volume of the medium, centrifuge it, wash it repeatedly, weigh it, or dry it and weigh it.

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