As the course of evolution has proceedin plants, what is the overall trend in the relationship of the diploid stage and the hapl
1 answer:
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Answer:
Phenotypic ratio= 1 Brown : 1 Gray
Explanation:
Genotype of brown snake= BB
genotype of gray snake= Bb
A cross between brown (BB) and gray (Bb) snake obtains progeny in following phenotypic ratio= 1 Brown : 1 Gray
Here, the heterozygous parent, gray snake (Bb) forms two types of gametes in 1:1 ratio while the homozygous dominant parent, brown snake (BB) forms only one type of gamete.
Answer:
<u>3) Uncontrolled cell division occurred as a result of gene mutations</u>
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Explanation:
Spontaneous modifications within the genome may occur during the process of cell division. When copies of the DNA inside the cell are made, these mutations cause errors; and can include small single nucleotide polymorphisms, and large scale additions or deletions across multiple genes.
Some, like somatic mutations, exist only inside vegetative (body) cells, that cannot be passed onto offspring. This is caused by several factors like
- UV radiation,
- chemical mutagens,
- infective agents
UV radiation damages strands of DNA, by causing dimers to form; here, consecutive nucleotide bases covalently bond instead of those on the complementary strand. This conformational change causes errors in DNA proofreading and repair mechanisms where bases are not well-incorporated into the strand- tumors (clumps of uncontrolled cell growth) may form, resulting in melanoma, a type of skin cancer.
