A researcher notices a decline in organism and population numbers over several years in a stream environment. What human activity may have affected organisms and populations in this way?

Geologists recognize three major types of plate boundaries, which are:

Every time a child visited a cousin who has two cats, the child's eyes turned red, itched, and began to water. Then, the child began to have trouble breathing.

What do scientists use to mark boundaries in the geologic time scale?

A human skin cell contains 46 chromosomes. How many chromosomes are present in a human egg cell? A 23 B 46 C 92 D 138

Select the choice that best completes the following sentence. Simple machines A. are made up of multiple moving parts. B. reduce the amount of energy needed to do work. C. are tools that make work easier. D.

Which of the following would most likely employ a forester? A. a state governments B. lumber businesses C. national govemments D. all of the above

How do environmental scientists use technology to track polar bears?

A rock formed from liquid magma at temperatures above 1000 degrees Celsius and the. Cooked and hardened what type of rock is it

You sample a population of butterflies and find that 56% are heterozygous at a particular locus. What should be the frequency of the recessive allele in this population? A. 0.07 B. 0.08 C. 0.09 D. 0.70

If there is a mutation in a zygote, where is it likely to be found in the fetus? A: The mutation will show up in any fetal cells formed by mitosis but not in those formed by meiosis.