Diffusion is the spontaneous movement of gases, without the use of any energy or effort by the body, between the gas in the alveoli and the blood in the capillaries in the lungs. Perfusion is the process by which the cardiovascular system pumps blood throughout the lungs.
Answer:
30
Explanation:
The seed of an angiosperm is formed as a result of fertilization (fusion of sperm in pollens and the ova from ovary). According to the question, the cells of the seed which will grow into the plant contains 20 chromosomes. Seeds of angiosperms contain a tissue called ENDOSPERM that forms as a result of the unique DOUBLE FERTILIZATION in angiosperms. It occurs when one haploid sperm cell fuses with two haploid polar nuclei to form a triploid endospermic structure that serves as food for the growing embryo in the seed.
Now based on the above explanation, the diploid plant cell with 20 chromosomes will have 10 chromosomes (half as much) in its gametes as a result of meiosis. This 10 chromosomes in each gamete (sperm and ovum) fuses to form a diploid zygote with 20 chromosomes, while one haploid sperm cell (10 chromosomes) also fuses with two haploid polar nuclei (10 chromosomes each) to form a triploid endosperm with 30 chromosomes i.e. 10+10+10.
Answer:
Totipotent (omnipotent) stem cells can give rise to any of the 220 cell types found in an embryo as well as extra-embryonic cells (placenta). Pluripotent Stem Cells Pluripotent stem cells can give rise to all cell types of the body (but not the placenta). Multipotent Stem Cells Multipotent stem cells can develop into a limited number of cell types in a particular lineage.
Explanation:
Plants, animals, and microorganisms
In mammals, alveoli is the region inside lungs where gaseous exchange occur between pulmonary blood and atmosphere.
