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:
Complete question:
___BLANK___ system contains glands that secrete hormones into the bloodstream, whereas the ___BLANCK__system secretes substances through ducts.
Answer:
The ENDOCRINE system contains glands that secrete hormones into the bloodstream, whereas the EXOCRINE system secretes substances through ducts.
Explanation:
Those tissues that produce hormones might be classified as:
- endocrine glands (produce hormones exclusively),
- exocrine glands (produce hormones and other secretions),
- non-glandular tissues that secrete hormones but are not glands.
- Endocrine organs, also known as ductless glands or endocrine glands, release their secretion directly to the bloodstream. Blood transport hormones to target cells, tissues, and organs, where they stimulate a change in metabolic activities
- Exocrine glands release their secretions to a duct of different tissues where they act, such as the internal or external surface of cutaneous tissues, stomach mucose, or pancreatic ducts.
Answer:
what is microscope is a laboratory instrument used to examine objects that are too small to be seen by the naked eye.
FUNCTIONS : The microscope is one of the most important tools used in chemistry and biology. This instrument allows a scientist or doctor to magnify an object to look at it in detail. Many types of microscopes exist, allowing different levels of magnification and producing different types of images
Answer:
Oxygen is needed to break the sugar into carbon dioxide, releasing energy the plants can use to stay alive. However, plants also take in energy from the sun(light), carbon dioxide from the atmosphere, and water from the soil; they use all of them in order to make sugar, and release oxygen.
Explanation:
Yes\.............................................
