Answer:
Radiometric dating methods
Explanation:
Absolute dating is the process of determining an age on a chronological or specified time scale in which events occurred in archaeology and geology. Absolute dating can be determined by using properties of the atoms that make up materials.
The most common method of absolute dating uses by geologists is radiometric dating methods which is based on the natural radioactive decay of certain elements such as potassium and carbon found in the rocks. By comparing the ratio of parent isotope with a known half-life to daughter product in the rock, the age of the rock can be determined.
The carbon-14 isotope is used in radiocarbon dating, but is only useful for measuring recently formed rocks in the geologic past. The decay of Potassium-40 isotope known as potassium-argon (K-Ar) method allows dating of materials that up to 1,000 billion years old.
The chloroplasts had inner membrane
Explanation:
The primitive photoautotrophs utilized hydrogen sulphide as the electron donor to perform photosynthesis for energy production.
Later upon understanding the endosymbiotic relationship of cyanobacteria which resided in the mitochondria of a eukaryotic host cell, the use of chloroplasts for photosynthesis was understood.
Generations after generations led to the development of chloroplasts by the cyanobacteria due to this symbiotic relationships which developed into the chloroplasts.
The unique presence of the inner membrane and its components like the stroma, thyllakoids helped the organism to utilize water as the electron donor for photosynthesis like the present day eukaryotes. This is the main reason why cyanobacteria is considered as the ancestor for eukaryotes.
Answer:
A sperm cell
Explanation:
A diploid cell has 46 chromosomes which is normally signified by somatic cells. Germ cells or gametes are haploid cells therefore they contain only 23 chromosomes. Male gamete contains 22 autosomes and one sex chromosome. That sex chromosome can be X or Y.
Female gamete does not have Y chromosome as a sex chromosome, it has only X chromosome as a sex chromosome. So Y chromosome in a human cell which have 22 autosomes determines that it is a male gametic cell or a sperm cell. Sperm cells that have a Y chromosome if fuses with female gamete produce male offspring(XY).
So the correct answer is- a sperm cell.
If they remain isolated for a long period of time, the two groups will probably diverge genetically, and may result in speciation.
Genetic divergence is the process whereby two groups of the same ancestral species acquire autonomous genetic changes through time, usually after the groups have been separated reproductively for some period of time.
Speciation is an evolutionary process whereby populations develop to become different species.
