2. a tall plant (tt) is crossed with a short plant (tt) if the fall f1 pea plants are allowed to self pollinate, a. the offspring will be of medium height b. all of the offspring will be tall c. all of the offspring will be short d. the offspring can be tall or short

The correct answer is D. the offspring can be tall or short

In a given cross, F1 pea plants are hybrid tall or heterozygous tall (Tt). If F1 plants are allowed to self-pollinate, as a result tall and short pea plants are formed in the ratio 3:1 respectively. This result obeys Mendel’s law of segregation which states that allele pairs separate or segregate during gamete formation, and randomly unite at fertilization.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.