<span>The diploid generation of the plant life cycle always produces spores. Diploid is itself a spore producing phase of an organism. These diploid cells produce haploid spores through meiosis. Egg in the ovule is fertilized by sperm that is released by pollen grains. This fertilization gives embryo that gives seed to sprout.</span>
During gas exchange, the cell membrane of a single-celled organism has the same function as the respiratory system in humans. The respiratory system is a biological system which is composed of specific organs and structures such as nose, pharynx, larynx, trachea, bronchi and lungs that are used for gas exchange in humans. The primary function of the respiratory system is to transport oxygen into the body and to breathe out carbon dioxide, which is a waste product of cellular function
1. The phrase Darwin used to describe his broad theory of evolution is ''descent with modification.
2. All of life is related through common ancestry, accounting for the Unity.
During the first one to two months of life, infants are incapable of deep sleep (they do not have trouble falling asleep but they do not generally stay asleep for very long stretches). This happens because infants can’t make the difference between night and day - they do not yet have a circadian rhythm. Around six weeks, the hormone melatonin is produced (pineal gland) and it helps establish a normal sleep-wake cycle.
