Answer:
scientists need to be able to use math because sometimes they need measurements and use equations to figure things out
Plants leaves, roots and stems are in the organ systems level.
—Evidence—
•] Plants contain just two organ systems. The shoot system includes all of the parts above the ground, such as leaves and stems, while the root system includes all of the parts below the ground, such as roots and tubers.
Answer and Explanation:
During the whole biota history, there occurred extinctions due to different reasons.
During the Cretaceous, which took place between 145-65 million years ago, there occurred a massive extinction that eliminated most of the species on the Earth. Many of the characteristic groups of this period were affected. Dinosaurs, Plesiosaurs, Ammonites, Tricodonts, Cycas, Gynkgos, Conifers, the recent angiosperms, birds, and mammals.
The extinction was caused by the volcanic eruptions, and the unusual fall of many different asteroids, which caused important changes on the Earth´s surface. The consequent climatic change was what ended affecting all the species directly. The extinction was gradual, although it occurred in a short geological lapse of time.
Mitosis occurs after the G2 phase in the cell cycle.
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
