C - 4
Possible gametes: AV, Av, aV, av
Answer:
D. Mass extinction events separate the three eras from each other
Explanation:
The Phanerozoic is an eon, thus it is representative of the largest unit of geological time. It is further divided into three eras. The three eras of the Phanerozoic are the Paleozoic, Mesozoic, and Cenozoic. These three eras have been divided on the basis of mass extinction events. The Paleozoic ends with the mass extinction at the end of the Permian period, which is also the largest mass extinction ever, and it also marks the beginning of the Mesozoic. The Mesozoic ends with the mass extinction at the end of the Cretaceous period, occurring because of a large meteorite or comet impact, marking the beginning of the Cenozoic era. The Cenozoic era is still going, and even though there have been extinction throughout it, none of them has been of a scale big enough to be considered as a mass extinction, so until something like that happens, this era will continue to exist.
Answer:
Muscles contract through a chain process of electrochemical signalling between the nervous system and muscles.
Explanation:
The muscle contraction is initiated by the nervous system by sending a signal. This signal also referred to as action potential travel through the motor neuron. This motor neuron releases a chemical signal to muscle when the electrical signal carried by it reaches the neuromuscular junction (a junction where motor neuron meets the muscles).
The chemical message referred to as neurotransmitter binds to the receptors present on the muscle fibers. These receptors causes the influx of sodium ion which in turn trigger the release of calcium ion thereby initiating the contraction of muscles.
Answer:
Consumptive rates are so high because water that is applied to a field is considered lost to the immediate water system. It either gets evaporated, used by the plants, or leaves the field as run-off. In addition, leaks or evaporation cause loss while water is being transported from the source to the field, often over great distances.
Answer:
a) (62 +68)/545
b) The two genes are linked.
Explanation:
a) The recombination frequency is equal to:
%
b) It can be seen that red plants with single flower and yellow with double flower are recombinant, this means that their parental combinations are uneven. This is due to a cross that occurred between the two genes. From the obtained result it can be said that both genes are linked.
