Explanation: Alveoli of lungs are surrounded by extensive blood capillaries. The partial pressure of oxygen in the alveoli is higher than the blood entering the pulmonary capillaries, hence oxygen moves into the blood. Carbon dioxide in the lungs simultaneously diffuse out of the blood into the alveolar space.

8 0

2 years ago

Passage of food through the digestive tract takes approximately

Oksana_A [137]

Food takes about 6 to 8 hours to completely pass through the digestive tract.

7 0

3 years ago

If a pea plant has a genotype SSTt what are the possible genetic combinations that could be present ina single grain of pollen p

Evgesh-ka [11]

Correct answer: D

A pollen is where male gametes are produced and so the number of chromosomes, as we are talking about gametes, is n. This means that the grain of pollen will only have a copy of each gene, and therefore only one allele for each gene - one S, and one T or t. So, the possible combinations are ST and St.

3 0

3 years ago