<span>Answer: Cellular differentiation is responsible for one daughter cell becoming a sieve tube whereas the other becomes a companion cell. Cell differentiation occurs as different genes are switched on and off.
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The expected phenotypic ratio for a cross between two individuals that are heterozygous for a given trait is 3:1.
<h3>What is Phenotype?</h3>
This is referred to the physical characteristics of an organism such as the size, shape etc.
When two heterozygous traits are crossed:
Rr × Rr ⇒ RR Rr Rr rr
The ratio is therefore 3:1 of the dominant to recessive phenotype.
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The correct answer is Deletion.
DiGeorge syndrome, more commonly considered as 22q11.2 deletion syndrome. It refers to an ailment resulting when a small segment of chromosome 22 is missing. This deletion leads to poor development of many systems of the body.
The medical issues generally associated with 22q11.2 deletion syndrome involve poor immune system function, heart defects, a cleft palate, delayed development with emotional and behavioral issues, and issues associated with diminished levels of calcium in the blood.
Answer:
1
Explanation:
Lichen are usually the first thing to grow on bare rock, making them a pioneer species. Fun fact, you can use lichen to determine if the air quality in an ecosystem is polluted.
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