Question in English:
A female carries a recessive lethal gene (l) on one of her X chromosomes, and a normal dominant allele (L) on the other. What is the sex ratio to be expected in this woman's dependency if she marries a normal man?
Answer:
2/3 females
1/3 males
Explanation:
Females have two X chromosomes (XX) and males have an X and a Y chromosome (XY).
The genotype of the female is XLXl. The genotype of the male is XLY, since he is normal.
The possible genotypes are:
<u> XL Xl</u>
<u>XL</u> <em>XLXL XLXl</em>
<u>Y</u> <em>XLY </em><em>XlY</em>
<em />
All female offspring will be normal as they will always have one normal copy of the X chromosome from their father.
50% of the male offspring will be normal, but 50% will inherit the lethal gene from their mother.
Because the allele is lethal, that means XlY males will not be born.
That means 2/3 of the children will be females, and 1/3 will be males.
Answer:
C. Bases
Explanation:
Deoxyribonucleic acid, commonly known as DNA, is the a type of nucleic acid that serves as the genetic material in living organisms. DNA holds information or instructions needed for the synthesis of useful products like proteins that is responsible for growth, reproduction, and general survival of organisms. Hence, it is referred to as the "BLUEPRINT OF LIFE".
However, in the structure the of the DNA molecule, it contains certain monomeric building blocks called NUCLEOTIDES. These nucleotide bases are of four types namely: Adenine, Thymine, Guanine and Cytosine. It is upon these order of nucleotide bases that instructions, or 'code', in our DNA is dependent upon.
Discovery In 1928 it was discovered by Frederick Griffith in an experiment generally known as transformation.
Experiment
In his experiment he considered two strains of <em>streptococus pneumonia,</em> one was R-type which was non-virulent and cause no disease in mice, other was virulent and S-type which cause disease and at last death of mice.
This experiment was comprised of four steps which are as follow:
Step 1: First he injected living strain of S into mice, after sometime mouce died.
Step 2: He injected living strain of R into mice, the mice alive as he did not got any disease.
Step 3: He injected heat killed strain of S into mice and mice remain alive.
Step 4: He mixed living R strain with heat killed S strain and then inject into mice. As a result the mice died.
Conclusion: It was found that genetic material from heat killed S stain were transferred to living R (non-virulent) strain, as a result R become virulent and cause the death of mice.
Answer:
Cells produce CO2 and use O2 thats why there is less oxygen in exhaled air bc cells used some and more CO2 bc body gets rid off extra CO2 like that
Explanation:
I hope I did't over complicate
I know only three specific ones. They are: forebrain, midbrain, and hindbrain.