Answer:
organelles are very similar to present-day bacteria, suggesting a common ancestor.
Explanation:
Some evidence suggests that some organelles like mitochondria and chloroplasts within eukaryotes were once used to be independent eukaryotes.
Endosymbiosis theory says that ancestral prokaryotic cells engulfed bacteria like cyanobacteria which with time evolved into mitochondria and chloroplast. Molecular evidence also proves that these organelles were once prokaryotic organisms because they show similar genetic makeup and ribosome type.
So these organelles are similar to present-day bacteria showing that they have a common ancestor.
The respiratory system is a biological system consisting of specific organs and structures used for gas exchange in animals and plants
Answer:
the allele combination for a trait
Explanation:
The genotype describes which alleles (versions) of a gene an organism has. Diploid organisms, such as humans, have two copies of each gene. Sometimes these alleles are the same and the individual is h0m0zygous for that gene. If they are different, the individual is heterozygous for that gene.
The physical appearance of a trait is the phenotype.
Answer:
The correct answer would be:
A G C T
Human: 31 19 19 31
Cow: 28 22 22 28
Salmon: 29 21 21 29
Wheat 27 23 23 27
Yeast 31 19 19 31
Explanation:
According to the rule of Chargaff which states or explains the amount of the A, T, G, and C bases in the DNA molecule. It says that the DNA of any organism should have a pyrimidine and purine ratio of 1:1. This means the amount of A would be equal to T and the amount G should be equal to the amount of C.
It also says that the amount of a and G would be equal to the amount of C and T. So on the base of this we can find the missing value in the table:
A G C T
Human: 31 19 19 31 (A= T and G=C)
Cow: 28 22 22 28 (A= T and G=C)
Salmon: 29 21 21 29 (A= T and G=C)
Wheat 27 23 23 27 (100 - A+T = G+C)
Yeast 31 19 19 31 (A= T and G=C)
Down syndrome and Alzheimer's disease.
Down syndrome is a chromosomal disorder which is caused by the presence of extra copy of chromosome 21. Therefore also called as Trisomy 21.
Alzheimer's disease is a most common form of dementia(reduction in brain functioning). It is caused by mutation in single gene APP (Amyloid Precursor Protein) present on chromosomer 21.
