Which of the following statements correctly describes the meaning of the chromosome theory of inheritance as expressed in the early 20th century? A) Individuals inherit particular chromosomes attached to genes.
B) Mendelian genes are at specific loci on the chromosome and, in turn, segregate during meiosis.
C) No more than a single pair of chromosomes can be found in a healthy normal cell.
D) Natural selection acts on certain chromosome combinations rather than on genes.

You hate the smell of mercaptoethanol. since there are no disulfide bonds in intracellular proteins, you have convinced yourself that it is not necessary to treat a cytoplasmic homogenate with mercaptoethanol prior to sds-page. you heat a sample of your homogenate in sds and subject it to electrophoresis. much to your surprise, your gel looks horrible; it is an ugly smear! you show your results to your friend who is a chemistry major, and she suggests that you treat your sample with n-ethylmaleimide (nem), which reacts with free sulfhydryls. you run another sample of your cytoplasmic homogenate after treatment with nem and sds. now the gel looks perfect! if intracellular proteins don't have disulfide bonds (and they don't) why didn't your original scheme work? and how does treatment with nem correct the problem?

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 a lab, scientists grew several generations of offspring of a plant using the method shown. what conclusion can you make about the offspring? a. they formed from meiosis and mitosis. b. they have half the number of chromosomes as their parent. c. they have low genetic variability among them. d. they will be able to reproduce only after they grow flowers.