The elastic artery absorb most of the shock when the heart ejects blood. The expansion stores energy; the recoil disperses this energy by moving blood further through the circulation.
Answer:
In bryophytes, the sporophyte is minute and dependent on the relatively prominent and nutritionally independent gametophyte for resources. The moss gametophyte looks like a miniature herb, with tiny leaf-like photosynthetic organs. The gametophyte generation begins as a dormant spore, which germinates under appropriate conditions to produce filamentous and branching protonemal tissues. These form multicellular bud-like structures, each of which develops into a leafy shoot. The mature gametophytes produce male and female sexual organs, the antheridia and archegonia, respectively. The gametophyte is often sexually distinct, and plants are either male or female.
Each antheridium has an outer layer that encloses and protects thousands of motile sperm, which swim through available external water layer to the egg. Fertilization at the base of the cylindrical archegonium produces a diploid zygote which develops into an unbranched sporophyte. The sporophyte consists of a thin stalk attached to the gametophyte, and a capsule that encloses the sporophytic meiotic cells.
In recent years, the mosses Physcomitrella patens and Funaria hygrometrica have emerged as attractive model systems for studying gene function in non-vascular plants because of the relative ease of molecular manipulation by homologous recombination. Mutants affecting gametophyte development have been isolated and their analysis should provide insights into the molecular basis of gametophyte development in mosses.
Explanation:
Answer:
b) biosphere
Explanation:
The biosphere is made of three parts, called the lithosphere, atmosphere and hydrosphere.
Http://www.lcps.org/cms/lib4/va01000195/centricity/domain/4153/study%20guide%20-%20geography%20unit%201%20answer%20key.pdf
Answer:
Cuttings: Pieces of stem or root cut from a plant to produce new plants
Herbaceous cutting: type of cutting taken from plants that never form a woody stem
Leaf cutting
:a cutting that includes a short section of stem with a leaf attached
Stem cutting
: a cutting made from short pieces of thickened leafless stems containing at least one node.
Air layering
: a type of layering in which the stem is girdled, the cut is dusted in rooting hormone, and the dusted cut is covered with moss
