Hypertension is a complex trait with multiple environmental and genetic contributors. Linkage studies of rare Mendelian disorders of hypertension and hypotension have produced the most notable progress toward understanding the heritable basis of blood pressure. Association studies to identify common variants have been limited in the past by small sample sizes and most findings lack replication.<span>
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97 Electrons are in Britannium
Answer: The blank can be filled correctly by "if the seeds contain the gene or allele responsible for large size of the tomatoes"
Explanation:
In plants also, characters or traits of characters are defined by genes. Different alleles produce different traits of the same character.
For example, in classic Mendelian genetics, T was the allele responsible for tall plant trait while t was the responsible for dwarf trait.
Similarly, there would be a gene(s) responsible for size of the tomatoes. In addition, seeds are the products of sexual reproduction of plants. So, they may carry genetic combination different from parent plants (due to meiosis, crossing over, independent assortment, et cetera).
So, if the seed contains the gene or allele responsible for large size of tomatoes then only they will produce same kind of tomatoes.
If grey feathers is a recessive trait, then 72.8% of the population is heterozygous for this trait.
Explanation:
The concept used here is of Hardy Weinberg principle, 
+2pq =1
The homozygous dominant genotypeis represented as 
= 84
Red = dominant
The homozygous recessive genotype trait is represented as 
= 16
grey = recessive
2pq = heterozygous individual
Thus for dominant homozygous the alleles are given as
p= 
= 9.1
q = 
= 4
for heterozygous individual 2pq
2 x 9.1 x 4
= 72.8
72.8% population is heterozygous for the trait.
