Of these four scientific designs, choose the one that has a biased design.
1.in a study to determine how bees react to color, both color and light levels are varied.
2.in a study of the effect of temperature on chick hatching times, all variables are controlled except temperature.
3.in a study of the effect of a vitamin on energy levels, the experimental and control groups each have 50 randomly chosen people.
4.in a study of the effect of an antibiotic on bacterial populations, there are several experimental groups at different antibiotic concentrations and one control group receiving no antibiotic.

Which phrase is the best summary of the model shown? a. the transfer of the sun's energy through trophic levels b. a series of aerobic and anaerobic reactions c. a transformation of light energy into chemical energy d. the breakdown of food molecules

Which of the following is a feature of all cells? o a. all cells have a nucleus. o b. all cells have dna for at least part of their life cycle. het . o c. all cells are spheres. o d. all cells have a rigid cell wall.

Suppose a point mutation, such as a change from an adenine to a guanine, occurs in the genome of a human sperm cell. the mutation could occur in any region of a gene. the effect of the mutation on the phenotype of the offspring will be determined by where the mutation occurs and its effect on the final gene product. in which of the following scenarios could the mutation alter the phenotype of the offspring? select all of the scenarios that apply the mutation occurs in the promoter and affects the rate of gene transcription. the mutation results in a new, dominant allele the mutation occurs in a portion of an intron not responsible for exon splicing the mutation occurs in a gene that controls development and alters differentiation of a cell type during development. the mutation occurs in a codon and alters the function of the final protein e mutation occurs in a codon, and the amino acid sequence of the final protein is unchanged.