Answer:
Listen to pronunciation. (al-VEE-oh-ly) Tiny air sacs at the end of the bronchioles (tiny branches of air tubes in the lungs). The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out.
Answer:
Recessive
Explanation:
A recessive disorder is expressed in a homozygous genotype only. Most of the recessive disorders are not expressed as the expression of the recessive allele is masked by a dominant allele in the heterozygous state. However, breeding between close relative (inbreeding) increases the homozygosity in the population and allows the expression of recessive alleles that were otherwise not expressed in the population.
According to the given information, the disease is rare and is mostly expressed in the progeny obtained by mating between closely related individuals (the first cousins). Therefore the disease is inherited in an autosomal recessive pattern.
Answer:
a Anaphase I
b Metaphase I
c Telophase I
d Anaphase II
e Prophase I
f Telophase II
Explanation:
Prophase I begins after the DNA has been duplicated, as shown in picture e. The chromosomes are condensed, and also visible, which is apparent in picture e.
The next stage is called Metaphase I, in which the pairs of homologous chromosomes align at The the centre of the cell and the spindle fibres attach, as shown in picture b.
The pairs of chromosomes are pulled apart to opposite poles of the cell by the spindle fibres., as shown in picture a. This stage is called Anaphase I.
Then, a process called Telophase I occurs, when the cell divides into two daughter cells. One of these cells is shown in picture c.
Picture d shows the stage Anaphase II, where the spindle has attached and the chromatids are pulled to the opposite poles of the cell.
The final picture left is picture f, which shows the daughter cell at the end of meiosis II, where the nuclear envelope is reforming, as in telophase II.
It involve both experimentation and repeated observations
<h2>Cell Cycle
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Explanation:
Eukaryotes grow and divide by cell cycle.
The main parts of a cell cycle are an ordered series of events – Gap 1 or G1 phase, Synthesis or S phase, Gap 2 or G2 phase, and the mitosis or M phases.
Interphase period (G1, S, G2 phases) - cell grows by size, duplicates its content, replicates its DNA, and finally prepares for mitotic cell division
.
Mitosis and cytokinesis - formation of two identical daughter cells
Cell cycle is regulated by regulatory or restrictive checkpoints in the cell cycle which are activated with detection of a defective DNA.
Proliferation of undesired or cells with defective DNA like in case of tumor cells is controlled by the action of suppressing agents like p53 and cyclins.
The tumor suppressor gene protein p53 prohibits division of tumor cells. Cyclins regulate cell cycle by activation of the enzyme cyclin-dependent kinase.
