<span> the common use of each tool used by space scientists and earth scientists are </span>tools that magnify objects:
telescope, microscope, magnifying glass, binoculars
tools that don't magnify objects: ruler, radio dish, streak plate, wind vane are all examples.
Answer: primary succession pioneer species would include Lichens, fungi, bacteria, fireweed, grasses,and alder.
Hey there! Cellular membrane and cell wall is your answer.
Answer:
a. two sperm enter the ovule; one fertilizes the egg, one fuses with 2 polar nuclei
Explanation:
Double fertilization is the characteristic feature of the angiospermic plants. After pollination, pollen grains deposited on the stigma of the pistil or carpel. The pollen grain on the stigma germinates forming a pollen tube. The pollen tube carrying two male gametes grows down through the style of the pistil and enters into the embryosac formed within the ovule and releases two male gametes.
One of the gametes fuses or fertilizes with the egg forming zygote. The other male gamete fuses with the two polar nuclei of the embryo sac. The fertilization between two polar nuclei and one male gamete is called the triple fusion. The triple fusion results in triploid primary endosperm cell (3n).
Thus, in angiosperms, there are two fertilizations called double fertilization resulting in the zygote (2n) and primary endosperm cell (3n).
Answer:
An <u>antibody</u> is a protein that is produced by the <u>immune system.</u> Their main job is to protect the body from invaders like bacteria, viruses, and parasites, which are collectively called, <u>antigens.</u> Chemical substances are also considered an <u>antigen.</u> These antigens trigger the production of antibodies as an immune response and seek and destroy them. An antigen like a virus encounters a <u>B-lymphocyte</u> (B-cell) first, which will produce antibodies that matches it. These antibodies will stick to the virus, marking them for the t-lymphocytes to recognize and attack.