A wildlife sanctuary is a place that is strictly controlled in order to protect a species from extinction.
Answer:
True
Explanation:
The Drosophila like the mammals possess X and Y chromosomes but as in males in which the XX is female and XY is male, the sex In Drosophila is not determined by the presence of Y chromosomes as a male determining factor are present on the autosomes.
However, the Y chromosome is important for males as they are involved in the formation of the sperms therefore the presence of Y is important. In the given question if the allele is present ion the Y chromosome which can reduce the size therefore the allele is passed on to the males only ans no females.
Thus, true is the correct answer.
the fly is female (Bridges 1921, 1925). Thus, XO Drosophila are sterile males. In flies, the Y chromosome is not involved in determining sex. Rather, it contains genes active in forming sperm in adults.
Answer:
The correct answer is "all of the above".
Explanation:
The missing options of this question are:
A. The major etiologic factor associated with SC is ultraviolet radiation, principally UV-B.
B. Factors predisposing to SC include skin phenotype, age, male sex, outdoor occupation, rural living, and host immune status.
C. AK and SC serve as clinical dose-meters for chronic UVR exposure.
D. All of the above.
The correct answer is option D. "All of the above".
Solar cheilosis (SC) is a type of precancer of the lower lip, induced by ultraviolet light exposure, particularly by the exposure of UV-B from sunlight. However, UV-B exposure is not the only cause of SC, there are different factor that predispose to the development of this disease, including skin phenotype, age, male sex, outdoor occupation, rural living, and host immune status. Particularly because people with an outdoor occupation is more expose to sunlight and people with an detrimental immunological condition cannot fight SC as easy as a healthy person. According to the scientific article "Epidemiology of actinic keratoses and squamous cell carcinoma" by Salasche SJ., Actinic keratosis (AK) and SC serve as clinical dose-meters for chronic UVR exposure
Answer:
The phenotypic ratio will be 3:1
Explanation:
As per this question there are two phenotypes for seed color, yellow and green. Both the parents are true breeding that means they are homozygous for this trait. Also, all the F1 plants have yellow seed color which clearly indicates that yellow seed color is a dominant trait while green is recessive trait.
The cross of true breeding plants as mentioned above is depicted as under:
Parents YY x yy
/ \ / \
F1 generation Yy Yy Yy Yy
So, as per the law of dominance because of the presence of Y allele, all these progeny will be yellow in color.
Next, when these F1 plants will be crossed, the result will be as under:
F1 generation Yy x Yy
/ \ / \
F2 generation YY Yy Yy yy
The genotypic ratio of F2 generation is 1:2:1
The phenotypic ratio of F2 generation is 3:1
It simply means that in F2 generation, 3 progeny which have allelic combination YY & Yy will be yellow colored while 1 progeny which has allelic combination yy will have green color.
