<span>C. The anther produces eggs. </span><span>
An angiosperm is a group of plants that consists of herbs, shrubs and trees. The angiosperms bear flowers and fruit. Its' seeds are not naked as they are covered by the fruit wall.
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All angiosperms produce flowers at some stage in their life. Flowers are important to the angiosperms because they serve as the reproductive organ for the plant, providing a means for the plant to propagate itself.
Angiosperms are the largest group of plants on earth. They account for approximately 80% of all known living plants. There are about 270,000 known species of angiosperms that live on the earth today.
Tyrosine is listed as a non-essential amino acid because it can be synthesised from the essential amino acid phenylalanine.
<u>Explanation:</u>
Amino acids are classified as essential and non essential according to whether they can be synthesized in the body itself or should be supplied by the diet. Essential amino acids cannot be synthesized in the body of the organism and thus can be obtained only from the diet. In the case of human beings, valine, phenylalanine, methionine etc are examples of essential amino acids.
Non essential amino acids can be synthesized within the body of the organism. Thus they need not be supplied by the diet. Alanine, aspartic acid etc are some of the non essential amino acids in human beings. It is given here that animals cannot synthesize tyrosine from shikimate-3p due to the lack of EPSP synthase.
But the amino acid tyrosine can be synthesized from the amino acid phenylalanine which is an essential amino acid. Thus tyrosine will be a non-essential amino acid.
The correct answer is I and IV
In the Basidiomycetes, the spores are produced externally on the end of specialized club-shaped structure called basidia. Whereas, In ascomycetes, spores are produced internally, in the sac-like structure called an ascus. Some members of ascomycetes cause plant diseases such as powdery mildew of grape (<em>Uncinula necator</em>), chestnut blight (<em>Cryphonectria parasitica</em>), and apple scab (<em>Venturia inequalis)</em>. Memers of basidiomyctes cause smut of corn (<em>Ustilago maydis</em>), brown root rot, and coffee rust.
Answer:
Background extinction
Explanation:
The background extinction refers to the diminishing of the species at a fairly slow and constant rate. This extinction takes place because of the various environmental factors namely the changing climatic conditions, spreading of diseases, and destruction of habitat. It plays an important role in the natural process of evolution. This has been taking place continuously throughout the geological time and the species are undergoing continuous evolution over a specific period of time.
During the initial exposure to the allergen, contact is made with B cells, these B cells differentiate and produce IgE antibody. The IgE antibodies which works against the allergens are released into the blood stream where they binds to Fc receptors which are located on mast cells and basophils. Now, the mast cells has become sensitized and they will wait patiently for the second exposure. When contact with the allergen is made the second time, the allergen becomes attached to the IgE present on the mast cells and this result in degranulation which trigger a lot of allergic responses.
