<u>Answer:</u>
<em>Sex ratio of the children can be predicted by making observations using Mendelian crossing methods. The genotype of parents are XX_(b ) and XY and the children are XX,XY,XX_(b ),X_(b ) Y.
</em>
<u>Explanation:</u>
<em>Given that the gene b is sex linked recessive and lethal. Being sex linked it will be associated with the X chromosome of affected or carrier individuals. </em>A man and woman who is heterozygous for this gene have children.
Females have two X chromosomes while males have one X and one Y chromosome. Thus one affected X chromosome doesn’t make a female an affected individual. She will be a carrier. If there only one X chromosome of the male is affected he will be an affected individual.
The genotype of the woman is and the genotype of the man is XY.
<em>The cross can be represented as </em>
<em>
</em>
<em>XX X_(b ) Y XX_(b ) X_(b ) Y
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Among the progenies the chance of the child being a female is ½ and being a male is also ½ among the two females one will be the carrier and the other is free of the lethal gene b.
<em>Among the two males, one male will be affected by inheriting X_(b )chromosome from the mother and the other will not be affected. </em>
The answer is D) to release energy from lipids stored throughout the body.
<span>Extraction of DNA is important because of many reasons. With the ability to remove DNA from an organism, scientists can observe, manipulate, and classify the DNA.
Scientists can identify genetic disorders or diseases from studying DNA.
Scientists can possibly find cures for these causes by manipulating or experimenting with this DNA.
Scientists can accurately sort organisms into classes because of DNA uniqueness. If we didn't have DNA extraction, it would be a lot harder to decide which organisms are different from each other.
Scientists can genetically engineer some organisms to produce beneficial things. A common example is that of insulin. Scientists can genetically engineer insulin production so that people with diabetes can live longer.</span>
Abiotic factors in common ecosystems:
1: Bats are interesting creatures, and use echolocation to make food
2: The cave walls help spread the voices of the bats
3: They have to use echolocation to breathe
Biotic factors:
1: Some good roles for bats are predators
2: They effect the system of computers when they bite computer chips
3: They complex human system life<span />
