Answer:
The correct answer would be D.Alveolar sacs are surrounded by thin capillaries where gases can be exchanged.
Alveoli are tiny sacs which form the site of gas exchange in the lungs.
The features of alveoli which help in gas exchange are:
- They increase the surface area in the lungs thus, more space is available for gas exchange.
- They have very thin walls, as thin as the thickness of a single cell only.
- They are surrounded by a bunch of thin capillaries which exchange gases with alveoli.
Snails are present in most of the world, so it is not a surprise to discover that they dwell in diverse habitats. Some of them are comfortable in the desert while others live in ditches and cooler climates. These include mountain areas and even marshes
Answer:
a. There are different possible ways that homologous pairs might line up
c. Different alignments of homologous pairs will cause different combinations of alleles in gametes.
Explanation:
The law of independent assortment, proposed by Mendel, states that the alleles of one gene segregate into gametes independently of the alleles of another gene. This means that the segregation of one gene does not affect another. This law of independent assortment is evident during gamete formation in sexually-reproducing organisms know as meiosis. Specifically, in the Metaphase 1 stage of meiosis 1, homologous chromosomes (similar but non-identical chromosomes received from each parent) lines up at the metaphase plate (cell equator).
The lining up of chromosomes in this stage occurs randomly making it possible for chromosomes to align in different possible ways. The way/manner the chromosomes align at the equator determines which chromosome combination gets separated into which gamete. The homologous chromosomes are randomly distributed at the cell's equator before segregates into gametes. This random orientation enables the alleles of each gene on a chromosome to combine in different random ways, hence, allowing genetic diversity in the resulting gametes (sperm and egg) they get segregated into.
