If the first trophic level in an energy pyramid receives 1,000 units of energy from the Sun, how much energy is available for the third trophic level?

10 units

Explanation:

Energy is transferred from organism to organism in an ecosystem when they feed on one another. However, based on the pyramid of energy, only about 10% of energy is transferred from one organism to another because a bulk of energy (about 90%) has been lost to metabolic activities.

Energy moves from producers to consumers, each occupying trophic levels. If the first trophic level in an energy pyramid receives 1,000 units of energy from the sun,

- 10% of 1000units will be available for the second trophic level i.e. 10/100 × 1000 = 100units

- 10% of 100units will be available for the third trophic level i.e. 10/100 × 100 = 10units

Hence, 10units of energy is available for the third trophic level.

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.