Answer:
Pollen grain lands on stigma
Explanation:
A) Pollen grain lands on stigma
- pollen tube grows down the style
- generative cell divides, forming two sperm
- two sperm are discharged to them female gametophyte
- sperm fuse with the egg and two polar nuclei
- zygote forms and divides into a terminal cell and a basal cell
- cells of embryo differentiate into three tissue types---- seed dries out and becomes dormant.
B)
- During pollination, a pollen grain is transferred from an anther to a stigma. Once the pollen grain lands on a suitable stigma, it germinates and forms a pollen tube, a structure that grows down through the style to the ovary.
- Once in the pollen tube, the generative cell from the pollen grain divides by mitosis, forming two sperm. The sperm travel down the pollen tube and are discharged into the female gametophyte. In a process called double fertilization, one sperm fertilizes the egg, forming the zygote; the other sperm fuses with two polar nuclei in the female gametophyte, forming a triploid (3n) nucleus. The zygote develops into the plant embryo, and the triploid nucleus divides and gives rise to the endosperm. Double fertilization prevents the waste of the plant's resources by ensuring that the nutrient-rich endosperm only develops if the egg is fertilized.
- After double fertilization, the ovule starts to develop into a seed containing the plant embryo. As the embryo develops, the three tissue systems are established, and the cotyledons (seed leaves) form. The seeds of many species dry out as they mature. These dry seeds lie dormant until suitable germination conditions occur.
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Below are the choices that can be found from other sources:
<span>a. 10 electrons
b. 6 electrons
c. 12 electrons
d. 16 electrons
e. 8 electrons
</span>
Answer is 6 electrons. <span>The part with the two units of + charge is a cation; the part with the unit of - charge is an anion.</span>
You know that during cellular respiration, energy is converted from glucose, in the presence of oxygen, into numerous ATP molecules. Glucose contains lots of energy, but that energy must be converted into a form usable by cells.
The nurse should position the client at a prone position every 3 to 4 hours for 20 to 30 minutes periods. This should be done periodically. Arterial insufficiency is any condition that slows or stops the flow of blood through your arteries. Arteries are blood vessels that circulate blood from the heart to other parts of the body.
Insect hormones and their receptors are a focus in pest control and research. Hence, Option B is correct.
Some of the insect hormones such as ecdysone (molting hormone), JH (juvenile hormone) and their analogs can be used for biological control of pests.
Option A: Hormone receptors are proteins that bind hormones and form hormone receptor complex to maintain cellular activities.
So Option A is incorrect.
Option B: Some of the peptide hormones used in pest control and research. So Option B is correct.
Option C: Peptide hormones interact with only cell surface whereas aminoacid derivatives and thyroid hormones directly interact with nucleus. so Option C is incorrect.
option D is incorrect.
Learn more on hormone receptor complex here:
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