Answer:
<h2>Geologic Time scale </h2>
<h3>Hope it helps you </h3>
There are five basic Hardy-Weinberg assumptions:
1. Random Mating -
2. No natural selection - all members of the parental generation survived and contributed equal numbers of gametes to the gene pool, no matter the genotype
3. No genetic drift (random allele frequency changes) - the population is infinitely large.
4. No gene flow - no new alleles were added by immigration or lost through emigration (no migration)
5. No mutation - There must be mutation equilibrium.
Answer:
The answer to this question is given below in this explanation section.
Explanation:
"advantages of interconnecting air sacs for birds"
The air sacs permit a unidirectional flow of air through the lungs.Unidirectional flow means that air moving through birds lungs is largely fresh air and has a higher oxygen content.In contrast air flow is bidirectional in mammals moving back and forth into and out of the lungs.As a result air coming into a mammals lung is mixed with old air has less oxygen. so in bird lungs,more oxygen is available to diffuse into the blood(avian respiratory system).
- The air sacs are thin membrane structures connected to the primary or secondary bronchi via ostia and they comprise most of the volume of the respiratory system.
- Air sacs are poorly vascularized by the systemic circulation and do not directly participate in significant gas exchange but act as a bellows to ventilate the lungs.In most species,there are nine air sacs which can be considered in cranial and caudal functional groups.
- The cranial group consists of the paired cervical air sacs,the unpaired clavicular air sacs and the paired cranial thoracic air sacs.
Answer:
Two heterozygous parents have a <u>50%</u> chance of contributing one of their alleles to each offspring.
Explanation:
Individuals who are heterozygous for a specific trait have two different alleles in the gene that determines that trait. This characteristic makes their chances of contributing each of their alleles to the offspring 50%.
The alleles of a gene are distributed in the gametes by the process of meiosis, which results in daughter cells with half the genetic charge, so each gamete can only have one copy of the allelic pair of a gene.
On the other hand, if an individual has two equal alleles for a characteristic in a gene, he has a 100% chance of passing that allele on to his descendants.
Answer:
Before cell division must occur, the chromosomes must replicate themselves. Sister chromatids are the two initially identical copies.
