What kinds of things has air pollution done? why should we care?

6. in the dna double helix, how are the two strands of dna held together? a. chemical bonds between base pairs hold the two strands of dna together. b. hydrogen bonds between the base pairs hold the two strands of dna together. c. hydrogen bonds between sugar groups and phosphate groups hold the two strands of dna together. d. chemical bonds between sugar groups and phosphate groups hold the two strands of dna together.

Arrange the following in the correct sequence, from earliest to most recent, in which these plant traits originated. 1. sporophyte dominance, gametophyte independence 2. sporophyte dominance, gametophyte dependence 3. gametophyte dominance, sporophyte dependence a) 1 → 2 → 3 b) 2 → 3 → 1 c) 2 → 1 → 3 d) 3 → 2 → 1 e) 3 → 1 → 2

In eukaryotes, genetic information is passed to the next generation by processes that include mitosis or meiosis. which of the explanations identifies the correct process and supports the claim that heritable information is passed from one generation to another? a. mitosis, followed by cytokinesis, produces daughter cells that are genetically different from the parent cell, thus insuring variation within the population. b. during mitosis, dna replication occurs twice within the cell cycle to insure a full set of chromosomes within each of the daughter cells produced. c. in asexual reproduction, a single individual is the sole parent and passes copies of its genes to its offspring without the fusion of gametes. d. single-celled organisms can fuse their cells, reproducing asexually through mitosis to form new cells that are not identical to the parent cell.