B. Embryos are being collected by the student on the field trip.
Material through which water flows is permeable. This material can be either natural or artificial. Naturally permeable material can be clean sand and gravel for example, or a sandstone and in the latter case the sandstone can have both porosity which is not synonymous with permeability as the pores must be connected to be permeable. An impermeable membrane could be used to line ditches for example to prevent leakage near mines.
I think tracheae which is B not sure tho
Mutations are changes that occurs in our DNA sequence, either due to mistakes when the DNA is copied or as the result of environmental factors such as UV light and cigarette smoke.
They increase the genetic variation within a species because they can create entirely new alleles in a population, random mating, random fertilization, and recombination between homologous chromosomes during meiosis which reshuffles alleles within an organism's offspring.
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