<span>Homologous chromosomes exchange DNA during meiosis in a process called crossing-over. Crossing-over sometimes involves an unequal swapping of DNA. Basically one chromosome in the pair gets extra DNA.</span>
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<h3>1. Hepatitis B </h3><h3>2. Levels of circulating antibodies against a certain antigen.</h3>
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<h3>Hope its help</h3>
Answer:
Option A, oxygen in the atmosphere
Explanation:
The highest level of oxygen reached during this phase of the geological cycle of earth. The oxygen level in Carboniferous period accounted for 35% as compared to 21% of oxygen in the atmosphere in present time.
Due to high oxygen content, the giant and wide varieties of terrestrial animal and plant species evolved. For example – size of insects and carwlies increased, plant became extremely giant, increase in number of tree ferns etc.
A piece of DNA from the parent to the offspring.
For example when you were born you're mum transferred some of her traits (hair color, personality ect.) on to you. Same with your dad. So you might look like your dad but have the same personality as your mum.
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