Answer:
Carbon dioxide plays an important part in vital plant and animal process, such as photosynthesis and respiration
Explanation:
Answer:
The correct answer is D. Reduced levels of circulating estrogens.
Explanation:
Estrogens prevent the loss of calcium and ensure its proper mineralization, thus preventing the bones from becoming brittle, maintaining the consistency of the skeleton and preventing osteoporosis. Osteoporosis is a skeletal disease in which there is a decrease in bone mass density. Thus, the bones become more porous, the number and size of the cavities or cells that exist inside them increases, they are more fragile, they resist shocks worse and they break more easily. Menopause is the definitive cessation of ovarian function that, externally, results in the disappearance of the menses and usually occurs around 50 years (the interval goes from 45 to 55 years). It is the gradual loss of calcium in the bones, which accelerates in the first years of menopause due to estrogen deficiency. At the beginning of the disease, there are no symptoms and, as it progresses, there is a tendency to suffer fractures, which leads to a decrease in height.
During this phase, the cell makes a variety of proteins that are required for DNA replication.
Answer:The Cycad tree is the sporophyte.They have flagellated sperm.
Explanation:
During pollination, the contents of the megaspore divide to form many–celled gamateophyte called the endosperm and archegonium. There is a micropyle opening with a sticky fluid, which traps the wind-borne male gametophyte (microspores) which,at this time is made up of prothallus cell;an antheridial cell and a large tube cell. The trapped microspore is sucked into the archegonia chamber. Antherizoids are released, but only one penetrates each oospore and fuses with the female nucleus. The zygote is formed in the ovule and the later develops into seed.The diploid seed germinates into a new sporophyte plant and the life cycle begins again. Examples of cycad include Cycas circinalis ,Cycas celebrical and Cycas revoluta
Since all thoroughbreds have the same birthday — January 1 — the best bet for a racing horse is to raise so that the foal drops right after that date. This means the yearling at his first birthday is a five-year-old and from then on he is ahead of the game with a five year of maturation before each.
