The lower respiratory tract is sometimes referred to as the tracheobronchial tree, this describes the branching structure of airways supplying air to the lungs, this includes the trachea, bronchi and bronchioles.
        
                    
             
        
        
        
Answer: A (AA x aa)
Explanation:
In option (A) both of the parent mussels are homozygotes, for alleles "a" and "A" respectively. Therefore, every single one (100%) of their offspring would be expected to be Aa heterozygotes. Combinations (B) and (D) yield a lower proportion of heterozygotes (50%), and combination (C) yields none at all. Punnett squares follow:
(A)
<u>   |  A      A        </u>
<u>a |  aA    aA      </u>
<u>a |  aA    aA      </u>
<u />
(B)
<u>   |  A      a       </u>
<u>A |  AA   Aa     </u>
<u>a |  aA    aa      </u>
<u />
(C)
<u>   |   A      A        </u>
<u>A |  AA    AA     </u>
<u>A |  AA    AA     </u>
<u />
(D)
<u>   |  A      a        </u>
<u>a |  aA    aa       </u>
<u>a |  aA    aa      </u>
<u />
 
        
             
        
        
        
Completely wipe out one of the other species.
-- CocaBeanz has got your back :)
        
             
        
        
        
Answer:
The correct genotype of the  two pure lines and the F1 is:
A⁺A⁺B⁰B⁰C⁰C⁰D⁰D⁰   and A⁰A⁰B⁺B⁺C⁺C⁺D⁺D⁺
The number of additive alleles on each genotype are two and six respectively.
Explanation:
Locus( plural form . loci) are fixed point on a chromosome in which genes are located. These genes are specific genetic material or genotype.
Now;
If we decide to designate the allele of the four loci into either additive (⁺) or non-additive(⁰); we have the following :
Let's the allele of the four loci to be 
A⁺/A⁰, B⁺/B⁰, C⁺/C⁰ and D⁺/D⁰
However, from the diagram below; we deduce that the correct genotype for the two pure lines and the F1 is as follows:
A⁺A⁺B⁰B⁰C⁰C⁰D⁰D⁰   and A⁰A⁰B⁺B⁺C⁺C⁺D⁺D⁺ and the number of additive alleles on each genotype are two and six respectively.
The cross between both F1 traits will yield an heterozygous individual for the offspring. i.e A⁺A⁰B⁺B⁰C⁺C⁰D⁺D⁰ with only four additive allele
 
        
             
        
        
        
Answer:
physical weather by ice icewedging 
Explanation:
i think its this one because it states that the water was frozen to 0 degrees meaning that the ice would expand the rock it can also be by water because the process is from water i can just tell u its not ersion