Answer:
d. both organisms have different ways of forming their lungs.
Answer:
B) There is an increase in the number of giraffes with long necks in areas of Africa where low-growing trees have died
Explanation:
The directional selection is one of the ways of the natural selection in which the natural selection selects or favours the most extreme trait of the species and the extreme trait show higher fitness than the normal or average trait.
In the given question, the case of Giraffe necks shows directional selection as the normal length of the neck is not favoured by the environment but the extreme trait that is long neck is favoured by the environment and the selection shifted to that level.
Thus, Option-B is the correct answer.
Chromosomes <span>structures</span> contain DNA within the cell nucleus
The alternation of generations
in the life cycle of a plant includes the diploid and haploid multicellular
stages. diploid and haploid are copies of the chromosomes. The spores in the
plant is unicellular and when they start dividing through mitosis, it produces
identical cells. These identical cells are all haploid. Haploid stages contain
one set of chromosome from either of the parent. These identical cells create a
multicellular system called the gametophytes. A gametophyte is the haploid
multicellular stage in the life cycle of a plant. The gametophyte makes the
gametes. These gametes are responsible for sexual fertilization. It takes place
when a sperm (male gametes) from the male fuses into the egg cell (female
gametes) of the female. The formation of both
male and female gametes creates a diploid zygote. Diploid stages
contain one set of chromosome from each parent. This is where the sporophyte
comes in. A sporophyte is the diploid multicellular stage in the life cycle of
the plant. It now contains the two sets of chromosomes from each parent.
The type of
cell division that produces gametes with half the normal chromosome number is
the meiosis. Meiosis is the type of cell division used in sexual reproduction.
It will occur in the testes and ovaries.
<span> </span>
