The sample method and the marker recapture method are commonly used to investigate the richness of p

This is not absolute, but it can be said in general.

Specifically, the sample method is used to count inactive organisms, such as plants and earthworms, and the recapture method is used to count animals with high activity such as mice.

In addition to this, there are also named calculations and visual estimations.

The sampling method and the marker recapture method are common methods to investigate the population density of plants and animals in the community, respectively.

By the formula: total number of individuals (n) number of marks captured for the first time (m) = number of individuals captured again (n) number of marks recaptured (m).

It gets: n*m=m*n

Now the markers make the animal vulnerable to predators, so the number of recaptured markers (m) becomes smaller, while m and n remain the same, so the calculated n is larger.

Hello! 1.On the large side.

The formula is n m = n m. where n represents the total number of populations; m indicates the number of first captures and markers; n denotes the number of second captures; m indicates the number of markers in the second capture of the individual. It should be that m is small, so n is large, and the calculated population density is also large (total number of individuals in the population) = total number of flags x number of recaptures) The number of individuals marked in the recaptured individuals can be known according to the title:

The animals caught in the marked recapture method are actually more difficult to catch again, indicating that the number of identified individuals in the recaptured individuals is small, and according to the calculation formula, it can be seen that the total number of individuals in the population of formula n will be larger, which will lead to an increase in the survey density. Pattern exploration: To determine the size of the survey data, the size of the final survey data can be determined according to the data in the formula that is improperly affected by the survey method of the topic information, and then according to the deviation characteristics of the data size.

1. The calculation formula of the marker recapture method: the number of individuals in the population (n) the total number of markers = the total number of recaptures The number of individuals marked in the recapture

2. It is not easy to catch again, and the number of individuals marked in the recapture is small, and the number of individuals in the population is large, so the answer is early rise: wrong.

a. The gray magpie has strong activity ability and a wide range of activities, and the population density can be investigated by the marker recapture method, which is correct; b. The range of activity of aphids is small, the activity ability is weak, and the sampling method can be used to investigate the population density, and B is correct; c. Sampling method for investigating the population density of dicotyledonous plants such as dandelion, C is correct; d, small animals in the soil have strong activity ability, and the body is small, generally not suitable for the use of sampling method and marking recapture method, to investigate the richness of small animal groups in the soil can be used sampler sampling method, d wrong so selected: d

1) m n=m n is too early to cherry n=mn m

2)32/x=4/36x=288

The number of individuals marked by the second capture of the lead band decreased, and the total number of calculated populations became larger and the proportion was higher.

4) 288 20000*100=only.

e. To investigate the population density of phototaxis insects, 3 methods can also be used to trap 3 methods with black light, E is wrong;

b. Evenly distribute 3 organisms, and the corresponding results can be calculated by simple sampling, and B is wrong;

c. Population refers to 3 is the sum of the agitation 3 of the same species of organisms in a certain area, and different populations in the clear and hidden areas are different, but different regions can be the same kind of organisms, c is false;

d. All 3 masson pines in a forest belong to the population, d is correct Therefore, d

Answer] A Answer Analysis] Test Question Analysis: The recapture method of marker leakage requires random distribution, and the crack is wrong to return to the side to pretend to be clustered, and at the same time, it requires that the marked and unmarked ** have an equal chance of catching, and it is not easy to fall off, so choose A.

Test Points: This question is designed to test students' understanding and application of the sign recapture method.

a. When the population density is investigated by the marked recapture method, the marked individuals can be completely mixed in the population, so that the probability of recapture is equal, and a is correct;

b. The probability of each individual being caught is equal, regardless of the marking status, age and gender, and B is correct;

c. The labeled individuals should be randomly distributed, so that the probability of the labeled individuals and the unlabeled individuals being recaptured is equal, if there is a swarm phenomenon, the survey results will deviate from the accurate value, and the results will be wrong;

d. The marker must not affect the normal life activities of the animal, nor can it cause disease and infection, and the marker must be kept for a certain time, at least during the investigation, and it cannot fall off, d is correct

Therefore, c

Is this the case, the "marker (record) recapture method" is a common survey method in animal population density surveys: in the living environment of the surveyed population, a part of the individuals (m) are captured and released after labeling, and after a period of time, the number of the population (n) is estimated according to the proportion of the number of marked individuals (m) in the recapture to the total number of captures (n). A research institute conducted an investigation on one of the main pests of the northern grasslands of China, the Bryde's vole.

The total area of the survey quadrat was 2hm2. (1hm2 10000m2), randomly lay 100 rat cages, place them for 1 night, count the number and sex of the captured rats, mark them and release them; 3 days later, a re-arrest and investigation will be conducted. The survey data obtained are shown in the table below.

1) Assuming that the proportion of markers in the recapture sample is equal to the proportion of markers in the total number of quadrats, the formula for calculating the total number of populations (n) in the quadrat is written 2) The average population density of Bryde's voles in this grassland is hm2. In fact, voles are more difficult to catch after being caught, and the average population density calculated above may be skewed compared to the actual population density

3) Based on the two captures, the sex ratio of the vole population ( ) is 4) At the same time as the above survey, the number of holes in the quadrat was also investigated (assuming that there is only one type of rat in the quadrat), with an average of one hole per 100 m2, and the ratio between the number of holes and the number of voles is

Answer; (1) n mn m (2) 144 high (3) 8 9 (or 32 36) (4): 1

What are you asking, the result?