The correct answer is D.
D. Anaerobic respiration evolved first; aerobic respiration evolved after photosynthetic organisms began producing oxygen.
Aerobic respiration take place in the mitochondria and requires oxygen, while anaerobic respiration does not. Anaerobic respiration evolved first and aerobic respiration evolved after photosynthetic organisms began producing oxygen.
<h2>Answer 17: </h2>The correct answer is C.
C. Each daughter cell receives its own copy of the parent cell’s DNA.
Cell division is the process by which a parent cell divides into two or more daughter cells. Each time when a cell divides each daughter cell receives a copy of the parent cell's DNA.
<h2>Answer 18: </h2>The correct answer is B.
B. four chromosomes
Mitosis is the type of cell division in which one parent cell divide into the daughter cells; each containing the same number of chromosome as parent cell. So if a cell has four chromosomes, and goes through mitosis to produce identical daughter cells so it will have four chromosomes.
<h2>Answer 19: </h2>The correct answer is A.
A. one
If a purple flower color is dominant (P) and red flower color recessive (p), the possible offspring of homozygous purple crossed with homozygous red (PP x pp) will be "Pp" and the only phenotype the purple colored flowers.
<h2>Answer 20: </h2>The correct answer is D.
D. polygenic
Polygenic is the phenomenon in which a trait is being control by more than two genes. So, in this case the fur color of dog is controlled by not only two genes but some other genes also influence it, so this is example of polygenic inheritance.
<h2>Answer 21: </h2>The correct option is A.
A. two
If T=tall, and t= short would be crossed Tt x tt, it will produce only two different genotypes. i.e. "Tt" and "tt". With reference to Mendel laws.
<h2>Answer 22: </h2>The correct answer is C.
C: 36.6%
According to the Chargaff's rule the percentage of cytosine in the DNA of the bacterium S. Lutea in Figure 12–3, should be around 36.6.
<h2>Answer 23: </h2>The correct option is B.
B. each nucleotide within a DNA strand can give a cell different information, and there are many nucleotides in every cell
DNA makes a good molecule for storing information because each nucleotide within a DNA strand can give a cell different information, and there are many nucleotides in every cell.
<h2>Answer 24:</h2>The correct option is A.
A. the double stranded nature of the helix and its dimensions
X-ray diffraction data collected by Rosalind Franklin and Maurice Wilkins helped Watson and Crick solve the structure of DNA. This data help them to know about the double stranded nature of the helix and its dimensions of the DNA.
<h2>Answer 25:</h2>The correct answer is B.
B. uracil
All of the nitrogen bases of DNA and RNA are the same except Uracil. Uracil is only present in RNA and absent in DNA.
<h2>Answer 26:</h2>The correct answer is A.
A. Several different codons can specify the same amino acid.
As there are 64 codons and 20 amino acids so it means that several codons can specify the same amino acid or one amino acid can be coded by more than one codons.
<h2>Answer 27: </h2>GCG codes for amino acid "alanine" and if we change it to GCC even then it will code for alanine.
so the correct option is A.
A. The amino acid ala is not changed.
<h2>Answer 28:</h2>The correct answer is C.
C. DNA to RNA to protein
This is called the central dogma of life in which firstly DNA is transcribed into RNA and then RNA is translated into protein.
<h2>Answer 29:</h2>As no figure is given so I am unable to answer this correctly. If the disorder is sex linked trait carried on the X chromosome. So if mother has two alleles it means she has disorder and if she has only one allele of disease. she can be a carrier for that disorder.
<h2>Answer 30: </h2>The correct answer is C.
C. restriction enzyme
Restriction enzymes are the endonucleases that are used to cut the DNA segments. Restriction enzymes can made sticky ends or blunt ends. They are widely used in recombinant DNA technology.