Answer:
Considering the <u>whole progeny</u> (100%), there will be
- 25% Black male kittens, XBY
- 0% Calico Male kittens
- 25% Calico female kittens, XBXR
Explanation:
<u>Available data:</u>
- The gene for Calico (multicolored) cats is an x-linked trait and codominant
- Calico Females receive a "B" and an "R" gene, and have black and orange splotches on white coats. Their genotype is XBXR.
- Males can only be black or orange, but never calico. Their genotype is XBY and XRY
Cross: a female calico cat with a black male
Parentals) XBXR x XBY
Gametes) XB XR XB Y
Punnett square) XB XR
XB XBXB XBXR
Y XBY XRY
F1) Among the whole progeny:
- 2/4 = 50% will be black (female XBXB and male XBY)
- 1/4 = 25% will be Calico (female XBXR)
- 1/4 = 25% will be Orange (male XRY)
Among females:
- 1/2 = 50% of females will be black, XBXB
- 1/2 = 50% of females will be Calico, XBXR
Among males:
- 1/2 = 50% of males will be black, XBY
- 1/2 = 50% of males will be orange, XRY
Gonads are the body structures that produce sex cells. Sperm are the male sex cells. Eggs are the female sex cells. Chromatin are threadlike DNA found inside the sex cells.
A benign tumour is generally not dangerous as they grow usually within a membrane in one space. They can however grow really big in a short space of time and can cause pressure on neighbouring blood vessels which can be dangerous.
Metastatic or malignant tumours are dangerous and cancerous. After they grow, some cells break off and travel in the bloodstream to a different area of the body (usually the main organs) and forms a secondary tumour there. This keeps happening until the cancer has spread to all of the body.
**_hope this helps**
Eutrophication is the overgrowth of algae in lakes and ponds
that is usually caused by the introduction of different chemicals
into the water from fertilizer run-off. Some ways to combat this
are to increase the flow of moving water, prevent contamination
from fertilizer, and reduce pollution of our lakes and streams.