<h2>Answer:</h2>
Because condensation on the slant effects the bacterial growth in the test tube.
<h3>Explanation:</h3>
- When agar is solidify in the test tube tilted, it takes a shape of slide on one side of the tube which is known as slat.
- Slant is used instead of petri dishes because they provide more surface area for growth.
- Water in the slat can invade the test tube, making agar unstable and the bacterial growth on the slat will be affected by moisture in bottom of slant.
- In petri dishes, it is no big problem of moisture condensation.
Answer/ Explanation:
a. The genotype of a homozygous white eyed long winged female would be Vg+Vg+XrXr. We denote the white allele as recessive (r) because the XY male only has one copy and yet has red eyes, so the red eye trait (R) must be dominant. A homozygous red eyed vestigial winged male would have be VgVgXRY. The possible gametes for the female are Vg+Xr only. For the male, the possible gametes are VgXR or VgY
The attached punnett square shows the results of the cross. The females will all be Vg+VgXRXr. The males will all be Vg+VgXRY (must inherit Y from father). That means they will all have normal length wings, the males will have white eyes and the females will have red eyes.
b. The F2 flies arise from intercrossing the F1, so the cross will be Vg+VgXRXr x Vg+VgXRY. The possible gametes for the mother are: Vg+XR, Vg+Xr, VgXR or VgXr. The possible gametes for the father are Vg+Xr
, Vg+Y
, VgXr
, VgY
. The attached punnet square shows this cross. The ratio of the phenotypes will be 6:6:2:2, or 3:3:1:1 (long-winged red eye: long-winged white eye: vestigial wing red eye: vestigial wing white eye), genotypes shown in the attachment.
c. F1 cross back to the mother would be Vg+VgXRY x Vg+Vg+XrXr. The genotypes are shown in the attached punnet square. The offspring will all be long-winged with white eyes. The F1 to the father would be Vg+VgXRXr x VgVgXRY. The ratio would be 3:3:1:1 long-winged red eye: long-winged white eye: vestigial wing red eye: vestigial wing white eye
Answer:
A. 2 cells are made from one cell
Answer:
Soil erosion.
Explanation:
No-till plowing can be defined as a farming method or technique which typically involves planting crops (seedlings) without tilling the soil rather the farmer would only open a narrow or very shallow trench of sufficient depth and width to cover up the seedlings. Thus, the no-till plowing makes crop residues to be left on the soil and by extension preventing soil erosion through the absorption of water by the crop residues.
Hence, by leaving crop roots in the ground and stalks on the surface, no-till plowing helps prevent soil erosion.
Additionally, the water retention ability of no-till plowing is usually a boon to farmers because it slows down evaporation and serves as a good protection for drought-stricken environments.
