Answer:
The proportion of oxygen went up because of photosynthesis by plants. The proportion of carbon dioxide went down because: it was locked up in sedimentary rocks (such as limestone) and in fossil fuels. it was absorbed by plants for photosynthesis.
Explanation:
Answer:
Meiosis is important because during sexual reproduction, it ensures that all produced organisms have the correct number of chromosomes. It is also responsible for producing genetic variations during the process of recombination, and it repairs some genetic defects.
The disadvantage from not having the trait normally arises only after the reproductive stage of the individual's lifecycle is mostly over. This is a special case of "no strong pressure", because evolution selects genes, not the organism. In other words the beneficial mutation does not alter the reproductive fitness.
Explanation:
Meiosis is important because during sexual reproduction, it ensures that all produced organisms have the correct number of chromosomes. It is also responsible for producing genetic variations during the process of recombination, and it repairs some genetic defects.
Virus: Vaccine, Antibiotics are not useful, Is not an organism
Both: Curable, Harmful to humans, Deadly
Bacteria: No vaccine, Antibiotics are useful, Is an organism
The answer is <span>B. In both oogenesis and spermatogenesis, the cells become haploid after meiosis I.
Gametogenesis is a process in which gametes are produced. Oogenesis is a process in which egg cells are produced and spermatogenesis is a process in which sperm cells are produced. Both processes include meiosis.
Original diploid cell (primary oocyte or spermatogonium) has 46 chromosomes. After meiosis I, there are two haploid cells. After meiosis II, there are 4 haploid cells because meiosis II is similar to mitosis. The difference between spermatogenesis and oogenesis is that those 4 cells after meiosis II in spermatogenesis are all sperm cells, and in oogenesis only one of them is egg cell.</span>
molecules will gain energy, causing them to move faster and spread further from each other
