Answer:
25%
Explanation:
When looking at a pedigree remember that:
- squares are males
- circles are females
- the solid colored figure represents an individual affected by a disease
- the empty figure represents a healthy individual
Let us assign the symbol X⁺ to represent the dominant allele linked to the X-chromosome and expressing healthiness, and X⁻ to represent the recessive allele expressing the dissease.
According to this pedigree
- I1 is a man affected by the disease, YX⁻
- I2 is a healthy woman X⁺X⁻
- we can see that among the progeny (generation II) there are two individuals affected (a boy and a girl) and one healthy girl. This means that the mother I2 is heterozygous for the trait.
So, having their genotypes we can know what are the probabilities of getting a son with DMD
Parentals) YX⁻ x X⁺X⁻
Gametes) Y X⁻ X⁺ X⁻
Punnett square)
X⁺ X⁻
X⁻ X⁺X⁻ X⁻X⁻
Y X⁺Y X⁻Y
F1)
- The probabilities of getting a healthy daughter X⁺X⁻ are 25%
- The probabilities of getting a healthy son X⁺Y are 25%
- The probabilities of getting a daughter with DMD X⁻X⁻ are 25%
- The probabilities of getting a son with DMD X⁻Y are 25%
Answer:
The function of a root hair is to increase the surface area available for absorption in plant roots
Explanation:
Root hairs are located mostly near a plant's root tips. Most water absorption occurs through the root hairs due to its large surface area for absorption of water. The root hairs acts as a protective mechanism to prevent harmful bacterial organisms from infecting the plant via the xylem vessels.
<span>These are organelles.
An organelle is the part of a cell that has a specific purpose in a cell. The structure of the cell is made up of many different organelles. The chloroplast consists of chlorophyll and the cell wall. The chloroplast helps with photosynthesis. Animal cells do not contain chlorophyll as they do not need photosynthesis to generate energy. A plant is unable to turn the sun's rays into a food source without photosynthesis.
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Answer:
B. False
Explanation:
Meiosis is a process where a single cell divides twice to produce four cells containing half the original amount of genetic information. These cells are our sex cells – sperm in males, eggs in females.
