Onion root tips are often used to study mitosis because they grow very rapidly, which means that many cells are dividing. The very tip of the onion root ends in a structure called the root cap. The other end of the root attaches to the onion. A scientist is interested in determining whether an onion root tip grows from the base of the root or from the tip near the root cap. She counts the number of cells that are in one of the phases of mitosis at different distances from the root cap. What is the dependent variable in her experiment

The construction of phylogenetic trees is a mapping out the proposed divisions and common ancestors of all living species. traditionally, these trees have been built using morphological data, such as appearance and embryology. recently, it has been possible to construct these trees using molecular data. phylogenetic trees based on different types of information agree with each: that there is strong evidence of a real underlying common descent. this phylogenic tree is composed based on molecular data (rrna). what statements can we infer are true about the organisms throughout the tree? because the tree is rooted, all branches share a common ancestor. all organisms have some sort of cellular structure/organization. all eukaryotes evolved from bacteria. since the organisms contain rna, they share the same dna. if the organisms contain rna, the share the same four nitrogen bases.

Researchers randomly divide participants into groups. each group takes a different amount of omega-3 fatty acid supplements daily for a month. one group receives a placebo. the researchers measure the impact on cholesterol levels in the blood. what is the purpose of random assignment in this experiment? a, to produce treatment groups with similar characteristics b, to ensure that all people with high cholesterol have an equal chance of being selected for the study c, to increase the accuracy of the research results and prevent skewness in the data

What determines the genotype or an organism