Answer:
Genotype of long winged fly is Ll
Genotype of short winged fly is ll
Explanation:
Given
Allele for long wing trait is "L"
Allele for short wing trait is "l"
When a long winged fly is crossed with a short winged fly, half of the offspring have long wings and other half have short wings as the ratio is 
Let us say that the genotype of long winged fly is Ll
and the genotype of short winged fly is ll
The cross between the two will produce following offspring
Ll * ll
Ll, Ll, ll, ll
Out of four off spring two have long wings (Ll)
and the other two have short wings (ll)
Thus the ration of long to short wing offspring is
i.e 
Answer:
A lethal mutation, thereby the resulting phenotype is not observed
.
Explanation:
Lethal mutations are the result of genomic changes that may be lethal in certain conditions. In genetic research, this type of mutation has shown to be very useful in analyzing gene function (i.e., genes whose protein products are key for the survival of the organism in question), and they are perfect gene markers. In bacteriophages, for example, temperature-sensitive mutants of phage T4 that can not grow at temperatures higher 42°C have been identified (Edgar & Lielausis 1964).
Citation:
R. S. Edgar, & I. Lielausis (1964). Temperature-sensitive mutants of bacteriophage T4D: their isolation and genetic characterization. Genetics, 49(4), 649.
Answer:
water, air , nutrients
Explanation:
water for circulation , air for breathing , nutrients for growth
Because only the chromosomes can be seen in a karyotype, and microdeletions or insertions are mutations at the molecular level, it is virtually impossible to detect such mutations at the chromosomal level.
The purpose of a dichotomous key is to identify organisms
Explanation:
A dichotomous key is a kind of a tool that guides to classify and identify different organisms.
This key as the name indicates - dichotomous- consists of two parts or options to identify a species.
The method utilizes a series of questions/answers with two possible outcomes.
Taxonomically, a dichotomous key is used to basically identify a species or an organism by its scientific name.
All of the natural elements like the plants, animals, birds, etc are identified using this key.
Types of dichotomous key includes nested, linked, branching tree etc.