Question

what components make up a nucleotide in dna?
○ a. sugar molecule, phosphate group, and nitrogenous base
○ b. sugar molecule, phosphate group, and oxygen atom
○ c. sugar molecule, nitrogenous base, and lipid group
○ d. phosphate group, lipid molecule, and nitrogenous base

what is the significance of mitochondrial dna?
○ a. it is found only in plants
○ b. it is inherited solely from the mother
○ c. it is inherited from both parents
○ d. it is responsible for protein synthesis

which of the following function of dna did you learn about? (select all)
○ a. conducting electrical impulses
○ b. synthesizing enzymes
○ c. encoding proteins
○ d. storing and transmitting genetic information

Explanation:

First Question: What components make up a nucleotide in DNA?

A DNA nucleotide consists of a deoxyribose sugar (sugar molecule), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). Option b has an oxygen atom which is not a main component of a nucleotide. Option c has a lipid group which is incorrect. Option d has a lipid molecule which is also incorrect. So the correct option is a.

Mitochondrial DNA (mtDNA) is inherited only from the mother (maternal inheritance). Option a is wrong as mtDNA is in animal cells too. Option c is wrong as it's not from both parents. Option d is wrong as protein synthesis is mainly by ribosomes and nuclear DNA - related processes, mtDNA is for mitochondrial - related functions. So the correct option is b.

• Option a: Conducting electrical impulses is a function of neurons, not DNA.
• Option b: DNA can be involved in synthesizing enzymes as enzymes are proteins and DNA encodes the information for protein (including enzyme) synthesis.
• Option c: DNA's main function is encoding proteins (through transcription and translation).
• Option d: DNA stores genetic information in its sequence and transmits it during cell division and reproduction.

So the correct options are b, c, d.

Answer:

a. Sugar molecule, phosphate group, and nitrogenous base

Second Question: What is the significance of mitochondrial DNA?