Answer: <u>Guanine
</u>
According to Chargaff's rule, the base pairing in the DNA and RNA is fixed. Adenine always pairs with Thymine in DNA and Uracil in RNA. Guanine pairs up with cytosine. This complementary base pairing is universal and constant. That's why amounts are also equal. It means if cytosine is 20% in any DNA sample, then amount of guanine would be 20% as well.
all cells look the same.
rest of the options are a part of the cell theory.
Answer:
Dopamine.
Explanation:
Cocaine is used as a recreational drug and addictive in nature. It can be smelled or directly inhaled in the veins. This drug causes the feeling of restless and happiness.
The dopamine is the important neurotransmitters that regulates the mood and other biological activity of the body. The cocaine inhibit the reuptake of dopamine and leads to its accumulation in the brain. This might also break the blood brain barrier.
Thus, the answer is dopamine.
Food web stability is most dependent on the number of connections among species.
Answer:
Explanation:
<u>a. How many chromosomes does a child receive from its father?</u>
Every person receives half of their chromosomes from their father and half from their mother. For that reason, if humans have 46 chromosomes in each somatic cell, 23 of them come from the father.
<u> b. How many autosomes and how many sex chromosomes are present in each somatic cell? </u>
Each somatic cell has 46 chromosomes in total; of which 22 pairs are autosomes and 1 pair are sex chromosomes. Therefore, 44 chromosomes are autosomes and 2 chromosomes are sex chromosomes (the X and/or Y chromosomes).
<u>c. How many chromosomes are present in a human ovum? </u>
The human gametes (ovum in women and sperm cell in men) have half of a somatic cell's genetic material, so that when they combine in a zygote to create their child, they form an initial cell with 46 chromosomes in total. The ovum therefore has 23 chromosomes: 22 autosomes and 1 sex chromosome.
<u>d. How many sex chromosomes are present in a human ovum?</u>
As I mentioned in the previous question, a human ovum has 1 sex chromosome. That way, when it combines with a sperm cell, which also has 1 sex chromosome, they form a zygote with <u>a pair</u> of sex chromosomes (one that comes from the mother and one from the father).
