3.2 Bio Content

Question 1

Gene

Answer 1

A discrete unit of hereditary information consisting of a specific nucleotide sequence.

Question 2

Central Dogma of Molecular Biology

Answer 2

Describes the flow of genetic information: DNA → RNA → Protein.

Question 3

Nucleic Acid

Answer 3

A polymer of nucleotide monomers that store and transmit genetic information.

Question 4

Three components of a nucleotide

Answer 4

Phosphate group, five-carbon sugar, and nitrogenous base.

Question 5

Ribonucleotide

Answer 5

The monomer of RNA; contains ribose sugar with an -OH at the 2′ carbon.

Question 6

Deoxyribonucleotide

Answer 6

The monomer of DNA; contains deoxyribose sugar with an H at the 2′ carbon.

Question 7

Purines

Answer 7

Nitrogenous bases with two rings: Adenine (A) and Guanine (G).

Question 8

Pyrimidines

Answer 8

Nitrogenous bases with one ring: Cytosine (C), Thymine (T), and Uracil (U).

Question 9

Phosphodiester linkage

Answer 9

Covalent bond between the 5′ phosphate group of one nucleotide and the 3′ hydroxyl group of another.

Question 10

DNA directionality

Answer 10

DNA has a 5′ end (phosphate) and a 3′ end (hydroxyl); sequence written 5′→3′.

Question 11

Chargaff’s rule

Answer 11

In DNA, number of purines equals number of pyrimidines; A=T and C=G.

Question 12

Watson and Crick

Answer 12

Discovered DNA’s double helix structure based on complementary base pairing.

Question 13

Complementary base pairing

Answer 13

A pairs with T (2 hydrogen bonds); G pairs with C (3 hydrogen bonds).

Question 14

Antiparallel strands

Answer 14

DNA strands run in opposite directions: one 5′→3′ and the other 3′→5′.

Question 15

DNA double helix

Answer 15

Structure with sugar-phosphate backbone outside and base pairs inside; hydrophilic exterior.

Question 16

DNA function

Answer 16

Stores and transmits genetic information required for growth and reproduction.

Question 17

DNA replication

Answer 17

Process where DNA is copied using base pairing to produce two identical daughter molecules.

Question 18

Steps of DNA replication

Answer 18

1. Strand separation, 2. Base pairing with free nucleotides, 3. Polymerization.

Question 19

RNA vs DNA sugar

Answer 19

RNA has ribose (with -OH); DNA has deoxyribose (with -H).

Question 20

RNA nitrogenous bases

Answer 20

A, U, G, C (Uracil replaces Thymine).

Question 21

RNA structure

Answer 21

Usually single-stranded; can fold into hairpin secondary structures.

Question 22

RNA secondary structure

Answer 22

Results from complementary base pairing within the same strand; forms hairpins.

Question 23

Ribozymes

Answer 23

RNA molecules with catalytic activity; can self-replicate and catalyze reactions.

Question 24

mRNA

Answer 24

Messenger RNA; carries the genetic code from DNA to ribosomes for protein synthesis.

Question 25

tRNA

Answer 25

Transfer RNA; brings amino acids to the ribosome during translation.

Question 26

rRNA

Answer 26

Ribosomal RNA; forms part of ribosome structure and aids protein synthesis.

Question 27

microRNA

Answer 27

Regulates gene expression by interfering with specific mRNA messages.

Question 28

Central Dogma summary

Answer 28

DNA replicates itself, is transcribed into RNA, and RNA is translated into protein.

Question 29

Chromatin

Answer 29

Complex of DNA and histone proteins in the nucleus.

Question 30

Chromosomes

Answer 30

Threadlike structures composed of tightly packed chromatin.