B. White petal colour is a recessive trait.
Explanation:
In Mendelian genetics, the alleles depicted in small letters are recessive traits.
Since both alleles are same and in lower case they are homozygous recessive alleles for a white coloured petal gene.
The genotype of the trait will be tt because if it is crossed either with heterozygous or homozygous P alleles it will appear as tt to have phenotypic trait of white colour.
So the genotype will be tt.
Answer: A
Explanation: All living organisims use energy
Answer:
Explanation: 1) Individual who is bald but neither parents has a widow's peak: As having a peak is dominant and the individual is bald with parents that doesn't have the trait, the genotype is recessive, in the case ww;
2) Individual has a widow's peak: The individual's genotype can be WW, homozygous for the trait or Ww, heterozygous for the trait, depending on the genotype of the parents;
3) Individual can't roll their tongue: Being able to roll the tongue is a dominant characteristics, so if the individual can't roll their tongue means the genotype is recessive. But, there is little evidence that this trait is dominant or inheritable;
4) Individual has a widow's peak but their mother does not: In this case, the genotype of the individual is heterozygous (Ww), because the mother is recessive (ww) and the offspring has the trait, so the father must have had it;
5) If an individual does not have a widow's peak (ww), which genotype would be impossible? If this individual crosses over with another individual with the same trait, their children will be all recessive for widow's peak (ww), so there is no possibility of an offspring with the trait;
If the initial individual crosses over with an individual with widow's peak, two possiblities can occur:
- If the crossover is with an individual homozygous for the trait (WW): all their children will have widow's peak with genotype Ww. So, the possibility of not having the peak is 0;
- If the crossover is with an individual heterozygous for the trait (Ww), there will be a probability of 25% for the children to have genotype WW, a probability of 50% for the offspring to be heterozygous (Ww) and has the trait and probability of 25% to be recessive (ww) and therefore doesn't have the trait;
The neritic zone is permanently covered with generally well-oxygenated water, receives plenty of sunlight and has low water pressure; moreover, it has relatively stable temperature, pressure, light and salinity levels, making it suitable for photosynthetic life.
