It's an sight observation you're using your eyes to see it it's one of your 5th sences
Production of the mature sperm cells have 4 step process beginning at puberty and throughout the male's lifetime. Spermiogenesis is the final process for production of sperm where the spermatids mature into motile spermatozoa. For humans, the spermatogenesis takes 74 days to 120 days and if the transport on the ductal system is included it would take 3 months.
The correct answer is B. Ordovician period
Explanation:
Plants are mainly multicellular organism that depends mainly on photosynthesis to obtain energy, this includes a wide variety of species such as grass, flowering plants, trees, shrubs, etc. Additionally, plants are considered as one f the two major divisions or kingdoms along with animals. In terms of history, it has been determined first land plants appear during the mid-Ordovician period around 470 million ago, although organisms that were the origin of land plants developed in water in previous periods, also by the Devonian period a wide variety of plants have emerged with features that are still part of plants nowadays. Therefore, plant life first appeared on land during the Ordovician period.
Answer: possibly A
Explanation: B an C are not it because they are more like mutations. D humans don’t always become immune.
Answer:
F = dominant, free earlobes
f = recessive, attached earlobes
father is "ff" then he has only two recessive attached earlobe alleles meaning he can only have attached earlobes. This is his phenotype, the visible trait produced by the genotype.
The mother is said to be "Ff". She has one dominant free earlobe allele (F) and one recessive attached allele (f). The dominant allele gets expressed as the visible trait (phenotype). = free earlobes
