dna structure

Question 1

. DNA Definition

Answer 1

DNA is a nucleic acid that stores genetic information and controls cellular activities, including protein synthesis.

Question 2

DNA Structure

Answer 2

DNA consists of nucleotides, which have three components: phosphate group, deoxyribose sugar, and nitrogenous base.

Question 3

Nucleotide Components

Answer 3

Nucleotides are made up of a phosphate group, deoxyribose sugar, and one of four nitrogenous bases (adenine, thymine, guanine, cytosine).

Question 4

Complementary Base Pairing

Answer 4

Adenine (A) pairs with Thymine (T), and Guanine (G) pairs with Cytosine (C) through weak hydrogen bonds.

Question 5

Double Helix

Answer 5

DNA has a double helix structure, where two strands of nucleotides wind around each other. Discovered by Watson and Crick.

Question 6

Chromosomes

Answer 6

DNA is organized into chromosomes, which are condensed structures containing genes. Humans have 46 chromosomes (23 pairs).

Question 7

Chromatin Network

Answer 7

DNA exists in a less condensed form as chromatin in the cell nucleus, except during cell division or replication.

Question 8

Genes

Answer 8

Genes are segments of DNA that code for proteins and are the units of hereditary information.

Question 9

Sugar-Phosphate Backbone

Answer 9

The phosphate groups and deoxyribose sugars form the backbone of DNA, connecting the nucleotides.

Question 10

Purines and Pyrimidines

Answer 10

Adenine and Guanine are purine bases with double rings, while Thymine and Cytosine are pyrimidine bases with single rings.

Question 11

DNA Replication

Answer 11

DNA replication is the process of copying DNA, ensuring genetic information is passed to daughter cells during cell division.

Question 12

Hereditary Information

Answer 12

DNA carries hereditary information in genes, influencing an organism’s traits and characteristics.

Question 13

Protein Synthesis

Answer 13

DNA provides instructions for protein synthesis, vital for growth, development, and cellular functions.

Question 14

Complementary Base Pairing

Answer 14

Adenine pairs with Thymine, and Guanine pairs with Cytosine through hydrogen bonds, ensuring accurate DNA replication and transcription.

Question 15

DNA Shape

Answer 15

The DNA molecule has a double helix structure with complementary base pairs forming rungs, discovered by Watson and Crick.

Question 16

Nucleotide Function

Answer 16

Nucleotides are the monomers of DNA, linked together to form a DNA strand through phosphodiester bonds.

Question 17

Weak Hydrogen Bonds

Answer 17

Hydrogen bonds between complementary bases (A-T, G-C) are weak, allowing DNA strands to be separated during replication and transcription.

Question 18

Chromosome Structure

Answer 18

Chromosomes consist of condensed DNA strands, including two chromatids joined by a centromere.

Question 19

DNA Code

Answer 19

DNA’s sequence of nucleotides encodes the genetic information necessary for an organism’s traits and functions.

Question 20

Genetic Replication

Answer 20

DNA replication involves unwinding the double helix, synthesizing new complementary strands using existing strands as templates, and forming two identical DNA molecules.

Question 21

DNA Function

Answer 21

DNA carries hereditary information, guides protein synthesis, and ensures genetic information is passed to offspring through replication.

Question 22

DNA Replication Process

Answer 22

DNA replication involves the separation of DNA strands, primer attachment, complementary nucleotide addition, and DNA strand elongation.

Question 23

Genetic Variation

Answer 23

Genetic variation arises from differences in DNA sequences, contributing to diversity within and among species.

Question 24

Chromatin vs. Chromosome

Answer 24

Chromatin is the relaxed, less-condensed form of DNA, while chromosomes are tightly coiled structures seen during cell division.

Question 25

Nucleotide Pairing Rules

Answer 25

Adenine pairs with Thymine, forming two hydrogen bonds, while Guanine pairs with Cytosine, forming three hydrogen bonds.

Question 26

DNA Helicase

Answer 26

DNA helicase unwinds the double helix during replication, creating single-stranded regions for nucleotide pairing.

Question 27

Semiconservative Replication

Answer 27

DNA replication is semiconservative, where each new DNA molecule consists of one old strand and one newly synthesized strand.

Question 28

Role of DNA in Heredity

Answer 28

DNA is the molecule of heredity, passing genetic information from parents to offspring through reproduction.

Question 29

Protein Synthesis Steps

Answer 29

Protein synthesis involves transcription (DNA to RNA) and translation (RNA to protein), guided by the genetic code.

Question 30

Central Dogma

Answer 30

The central dogma of molecular biology describes the flow of genetic information: DNA to RNA to protein.