The most likely explanation for the variation is the offspring were produced from different combination of genes. A single pair of gold fish mentioned in the question means a male and a female gold fish. The two of them mated and contributed different genes to the fertilized fish eggs, this results in production of various body shape and colouration which is known as variation.
A haploid cell is one that contains one set of complete chromosomes.
Answer:
It has 4 trophic levels.
Explanation:
The first level would be the producers, followed by the primary consumers, then the secondary consumers, then the tertiary comsumers.
/ Tertiary consumers \
/ Secondary Consumers \
/ Primary Consumers \
/ Producers \
/________________________________\
Isovelumetric relaxation and ventricular filling take place during Ventricular diastole.. Both occur during ventricular diastole when the ventricles are not actively contracting and ejecting blood. Ventricular diastole is the period during which the two ventricles are relaxing from contortions of contraction, then dilating and filling; atrial diastole is the period during which the two atria are relaxing, dilating, and filling.