That will be once every year
Answer:
Chromosomes become visible, crossing-over occurs, the nucleolus disappears, the meiotic spindle forms, and the nuclear envelope disappears.
Explanation:
The duplicated homologous chromosomes pair, and crossing-over (the physical exchange of chromosome parts) occurs.
Explanation:
The major blood vessels that are connected to the heart include the aorta, the superior vena cava, the inferior vena cava, the pulmonary artery (which takes oxygen-poor blood from the heart to the lungs, where it is oxygenated), the pulmonary veins (which bring oxygen-rich blood from the lungs to the heart) and the coronary arteries (which supply blood to the heart muscle).
Answer:
Energy flow in an ecosystem is unidirectional. It means that energy which is absorbed by the producers from sun and is converted into chemical energy, always flow from a lower trophic level to a higher trophic level as in a food chain when herbivore consumes producers the energy is transferred from producers to consumers and so on. Some of this energy is assimilated some is used by the organism and some is dessipated in the environment but the flow of energy is never reverted, that is obviously a producer can not consume a consumer.