Some methods of determining the size of population are direct and indirect observations, sampling, and mark-and-recapture studies
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Sampling - Done by counting the animals in a small area and then estimating how many are in the larger area. You go out and take samples from different places so you can take the average. In most cases, it is not possible to count every member of a population so an estimate is made.
Mark and recapture - Another estimating method is a technique called "mark and recapture." This technique gets its name because some animals are first captured, marked, and released into the environment. Then another group of animals is captured. The number of marked animals in this second group indicates the population size.
Indirect observation - The members of a population may be small or hard to find. It may be easier to observe their tracks or other signs rather than the organisms themselves.
Direct observation - The most obvious way to determine the size of a population is to count, one by one.
Answer:
Commensalism
It is a +/0 population interaction.
Answer:
The correct answer will be option-A.
Explanation:
The lac repressor is a protein produced by the regulator gene present in the lac operon called lacI gene. The repressor proteins bind to a DNA sequence called the operator and block the site for binding of RNA polymerase, thus shuts off the transcription when lactose is absent.
Lac operon is a homotetramer made of two dimers with two alpha-helix bundles which bind to different regions of the operator. The binding of the allolactose to protein causes conformation change in the protein due to which separates the binding helix of the DNA and inhibit the association of the protein to DNA.
Thus, option-A is the correct answer.
Question is which is NOT a good technique.
Answer is "B" and here's why:
A) Clear questions -- good. People understanding the question will answer accurately.
C) Large sample size -- good. Answers will be more accurate with more people asked (like if you flip a coin 1,000 times its going to be closer to 50% heads than if you only flipped it twice)
D) Random sample -- good. Avoids your own bias in choosing who to ask.
B) Push poll -- bad. Pretends to be unbiased, the pollster's real objective is to get a person thinking in a way that is to their advantage. Some political candidates do this just before elections.
Functional foods are foods that provide positive health benefits, particularly additional benefits apart from the basic nutrition provided by that food.
They are divided into two categories:
1. Functional foods that naturally contain a component that offers additional (health) benefits to the consumer,
2. Functional foods consisting of processed foods with added components for additional (health) benefits.
Examples of functional foods belonging to the first category include tomatoes, watermelons, fatty fish, and cranberries. Examples of functional foods belonging to the second category include breads and cereals with added fiber, orange juice with added vitamin D, and omega-3-enriched eggs.