C. ferns.
Explanation:
The ferns are ancient plants that have managed to survive until the present. They are not closely related to the dominant plants nowadays, the flowering plants, but instead they are closely related with plants that have gone extinct tens and hundreds of millions years ago. Even though the ferns are not the dominant plants, they have managed to find a niche and firmly hold onto it, so they remained widespread, normally occupying the lower layers of the forests.
Unlike the flowering plants that produce flowers and then seeds in order to reproduce, that is not the case with the ferns. The ferns actually reproduce through spores, being widely dispersed by the wind and managing to spread out and reproduce over relatively large territory very quickly.
This information is not enough to tell which of the traits-blood group A or O is dominant.
It is known that blood groups A and B are codominant, which means both will express if found together in a heterozygote. However, blood group O is recessive. But from this information, you can conclude that blood group O is dominant. Why is that so?
Let's imagine that father's genotype is AA and mothers' genotype OO and cross them:
Parents: AA x OO
Offspring: AO AO AO AO
Since we have information that daughter has blood group O, we can conclude that O is dominant over A and mask it. This is not true! In this case, the daughter will have blood group A.
Mother's genotype surely is OO (because O allele is recessive, so to express a recessive trait both alleles must be recessive). But, the father cannot be AA, because it must give O allele to the daughter so she can have genotype OO and blood group O. So, the father's genotype is AO. Let's take a look at that crossing:
Parents: AO x OO
Offspring: AO AO OO OO
Thus, in this case, daughter can have genotype OO and blood group O.
Answer:
3.dominant alleles more frequent than recessive alleles
Explanation:
To achieve hard-Weinberg equilibrium, certain conditions must be made.
These conditions are:
1. There is noo mutation,
2. Existence of random mating,
3. There should be no natural selection
4. There is the infinite population size
5. No migration
Hence, in this case, the correct answer is option 3, which is not a condition to be made for Hard-Weinberg equilibrium
The student who caught the cold caused by this specific Rhinovirus was exposed to the exact same Rhinovirus 18 months later. Memory B cells of the immune system will protect her from getting the same cold again.
In immunology, a memory B cell (MBC) is a type of B lymphocyte that forms part of the adaptive immune system. These cells develop within germinal centres of the secondary lymphoid organs.
Memory B cells circulate in the blood stream in a quiescent state, sometimes for decades. Their function is to memorize the characteristics of the antigen that activated their parent B cell during initial infection such that if the memory B cell later encounters the same antigen, it triggers an accelerated and robust secondary immune response.
Memory B cells have B cell receptors (BCRs) on their cell membrane, identical to the one on their parent cell, that allow them to recognize antigen and mount a specific antibody response.
Learn more about memory B cell here : brainly.com/question/23423029
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