Fire naturally occurs in a grassland ecosystem and it helps the environment stay healthy and strong. I promotes richer soil as well as gets rid of excess leaves scattered around. After a fire, grassland ecosystems can grow again and be better than they were before.
Answer:
In both groups, sperm swim from antheridia to archegonia
Explanation:
Bryophytes are the plant group that does not have a vascular system. These plants do not produce seeds. Ferns and horsetails are seedless vascular plants. These plants have vascular tissues (xylem and phloem) to serve in the conduction of water, minerals, and sugars from the one plant part to the other. But these plants do not produce seeds and hence, are seedless vascular plants.
Both bryophytes and the seedless vascular plants depend on water for fertilization. These plants release their male gametes in water which in turn move towards the female gamete. Sperms, the male gametes of these plants swim in the water to reach the female gamete.
Antheridium is the male gametangium that serves as a site for the production of male gametes while archegonia are the female gametangia where the egg cell is produced.
1. reduce the number of trips you take in your car
2.reduce or eliminate fireplace and stove use
3.avoid burning trash, leaves, and other materials
4.avoid using gas-peered lawn and garden equipment
The immune system<span> recognizes HIV by its antigen shape. But, just when the immune system recognizes one shape, HIV may multiply and change the shape of its antigen. </span><span>HIV can "hide" from the immune system for a long time. </span><span>When HIV infects a cell the </span>virus<span> may make more viruses and infect more cells or lie quietly in a cell for a long time. If HIV doesn't reproduce, the immune system can't find it and destroy it. </span>HIV destroys the immune system. The Immune system consists of Innate Immunity and Humoral Immunity Innate Immunity is Non-specific Immunity, whereas Humoral Immunity is specific Immunity. T-cells produce Cell-Mediated Immunity and B-cells produces Humoral Mediated Immunity. <span>As HIV destroys more and more helper T cells, the immune system begins to break down. </span> Finally the immune system can no longer kill HIV or any other invading germs and a person infected with HIV is diagnosed with AIDS.