Answer:
a mucus or a gelatinous sheath
Explanation:
Most species of cyanobacteria are enclosed in a gelatinous sheath which is made up of proteins.
Answer: For three traits inherited in a dominant/recessive pattern, the probability of an offspring in a trihybrid cross between parents heterozygous for all three traits to be recessive at exactly two of the three loci is 23/64.
Explanation: Let A, B and C represent the dominant alleles and a, b and c represent the recessive alleles. The genotype of each of the parent will be AaBbCc since it has been said to be heterozygous for all the three traits. There are eight (8) possible different types of gametes from each of the genotype. This can be calculated using 2^n where n is the number of heterozygous loci.
The number of heterozygous loci in the genotype AaBbCc is three (3). 2^3 = 8. The gametes are;
ABC
ABc
AbC
Abc
aBC
aBc
abC and
abc.
Therefore, sixty-four possible offsprings are expected from the cross AaBbCc x AaBbCc.
Out of these offsprings, twenty-three (23) are expected to be heterozygous at two loci as boldly shown in the attached image.
The correct answer is - D) covered by warm shallow seas.
The fact that the crinoids are have an abundance in the fossil records in Pennsylvania in the Mississippian Period, tells us that this area was covered with shallow and warm seas. The reason why we can get that conclusion is that the crinoids live only in that kind of environment, so it simply a logical conclusion.
The geological data is also confirming this, as it is easily noticeable in the layers that during this period of the geologic past, what is now Pennsylvania, was covered with shallow sea waters. Also, this waters were warm too, as the climate was warm and humid and that period, so it was a perfect environment for the crinoids to flourish.
Answer:
Kartegener's disorder
Explanation:
The respiratory tract has cilia which move. Sperms also have a tail that moves. They both have the same protein in their structure called microtubules. There is a disorder in which there is the absence of a part in the microtubule. Dynein arms absent in microtubules. Because the respiratory system and sperm both contain cilia that's why these two systems have a connection and not work properly.
Answer:
Women who carry one copy of the mutated gene still have normal color vision because they have another copy, which is not mutated, in the other X chromosome that will be the dominant one. As a result, the women are carriers of the mutated gene but not color blind.
Explanation:
Colorblindness is a sex-linked mutation. A woman has two X chromosomes, while a man has one X chromosome and one Y chromosome. The mutated gene that causes color blindness is on the X chromosome, and it is OPN1LW. So if a woman has one mutated OPN1LW in one of her two X chromosomes, the OPN1LW gene in the other X chromosome will be the dominant one stopping the woman from being colorblind.
In the case of men, as they only have one X chromosome, if there is a mutation on the OPN1LW in the X chromosome, the men will be colorblind because there is no extra copy of the gene, as it is in women.
