What is an observational study?
A) An observational study is a list of all individuals in a population along with a certain characteristics of each individual.
B) An observational study is whn a researcher assigns individuals to a certain group, intentionally changing the value of an explanatory variable, and then recording the value of the responses variable for each.
C) An observational study measures the value of the response variable without attempting the influence the value of either the response or explanatory variables

Factorize: x^2+8x+10 i just solved it but i don't know if the process is correct

This is the number of parts out of 100, the numerator of a fraction where the denominator is 100. submit

First to answer all gets a donation question 3(multiple choice worth 1 points) (04.01 lc) which of the following levels is lower than cells in the hierarchy of organization of living things? molecules organs organ systems tissues question 4(multiple choice worth 1 points) (04.01 lc) which of these represents an individual form of life such as an animal, plant, or single-celled life form? organ organism organ system tissue question 5(multiple choice worth 1 points) (04.03 lc) what are the green structures inside plant cells where photosynthesis takes place called? chloroplast mitochondrion nucleus vacuole question 6(multiple choice worth 1 points) (04.03 lc) which of the following best matches a part of a living cell with the function it performs? cytoplasm: fluid which carries the nucleus and other organelles vacuole: fluid which carries the nucleus and other organelles cytoplasm: directs all of the cell's activities vacuole: directs all of the cell's activities question 7(multiple choice worth 1 points) (04.03 mc) read the table below. organelles of plant cells present in both plants and animals present in plants but not animals small in animals but large in plants organelle a organelle b organelle c which statement is most likely correct? organelle a is chloroplast, organelle b is cytoplasm, and organelle c is nucleus. organelle a is mitochondrion, organelle b is cytoplasm, and organelle c is nucleus. organelle a is cell wall, organelle b is chloroplast, and organelle c is mitochondrion. organelle a is mitochondrion, organelle b is chloroplast, and organelle c is vacuole. question 8(multiple choice worth 1 points) (04.03 mc) what will most likely happen in the absence of a nucleus? genetic information will not be transmitted by the cell. energy will not be released during cellular respiration. the cell will not store food, water, nutrients, and waste. the cell will lose its shape and structure.