Answer:
Angiosperms have seeds with an 3n endosperm due to double fertilization.
Explanation:
- Double fertilization is found only in flowering plants.
- In angiosperms, the female gametophyte does not grow after reaching eight nucleate stage.
- After fertilization and triple fusion, the zygote and primary endosperm are created and further growth of embryo sac continues.
- Triple fusion is the fusion of two haploid polar nuclei of female gametophyte and one male nuclei. This results in a 3n nucleus.
- The developing embryo obtains nutrition from the endosperm.
- If fertilization fails no endosperm is formed.
Answer AND Explanation:
In spite being called the resting phase, many cellular processes take place during this phase. One of the most important of these is chromosomal replication in which each chromosome produces an exact copy of itself. The chromosomes are not visible as discrete structures but instead they appear as diffuse tangle of threads called chromatin.
Another important event is the formation of new organelles like mitochondria. There is also a build up of energy stores which is necessary to drive the mitotic process.
<h2><u>
Heart and lungs:</u></h2>
The upper chamber of the heart is called atrium and lower chamber of the heart is called ventricles.
The blood circulation in the heart is basically under the functioning of three blood vessels namely:
<h3><u>Arteries:
</u></h3>
- They start with the aorta, the huge vein leaving the heart.
- Veins divert oxygen-rich blood from the heart to the majority of the body's tissues.
- They branch a few times, decreasing and littler as they convey blood more remote from the heart.
<h3><u>Capillaries:
</u></h3>
- These are little; flimsy blood vessels that associate the arteries and the veins.
- Their dainty dividers permit oxygen, supplements, carbon dioxide, and other waste items to go to and from our organ's cells.
<h3><u>Veins:
</u></h3>
- These are the blood vessels that return blood to the heart; this blood needs (oxygen-poor) and is wealthy in waste items that are to be discharged or expelled from the body.
- Veins become bigger and bigger as they draw nearer to the heart.
- The unrivaled vena cava is the huge vein that brings blood from the head and arms to the heart, and the second rate vena cava brings blood from the mid-region and legs into the heart.
Explanation:
carbon dioxide released during decay.
Answer:
A Gene pool is best described as, all the alleles present in an population.
Explanation:
