<u>Answer</u>: Sperm cell
<u>Explanation</u>:
Amongst all the 4 options given, only the Sperm cell is a gamete (sex cell) while all the three are somatic cells.
- A <em>somatic</em> cell is the one which forms the body of an organism and contains all the genetic information.
- A <em>gamete</em> is the one which is required for the purpose of fertilization. A gamete of male fuses with the gamete of female in a process called fertilization to form a zygote to give rise to a new individual.
- A Sperm cell is basically a <em>male gamete.</em> It contains only half the amount of genetic information as the other half is contributed by the female gamete.
- This difference in the amount of genetic information arises due to the type of cell division that occurs. The somatic cells undergo mitosis whereas a gamete requires meiosis to occur for its formation.
- During mitosis there is a single round of cell division which divides the parent cell into two daughter cells each with the <em>complete genetic information</em>.
- During meiosis the cell undergoes two rounds of cell division such that a total lf 4 cells are produced each <em>with half the amount of genetic material </em>as present in the parent cell.
Since, <em>sperm is a male gamete and is formed by meiosis it contains only half the genetic information as compared to the other cells.</em>
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:
A.) Smell is a chemical sense.
B.) Odorant molecules dissolve in mucus before stimulating a receptor
C.) Olfactory receptors have hairs on the apical surface that respond to stimuli
The answer is A smaller fragments will move faster.
