W3-The nature of genes and the genome

14 Questions

What is the role of the nucleus in an animal cell?

Site of DNA replication and transcription

How many nucleotides are present in the human genome?

3.2 billion

What does the term 'autosomes' refer to in the context of the human genome?

Non-sex chromosomes

Where is the circular chromosome found in human cells?

Mitochondria

What is the main function of the nuclear envelope?

DNA packaging

What is the size range of the nucleus in an animal cell?

3-10 µm

What does the nucleolus in the nucleus of an animal cell produce?

Ribosomes

Which molecule has a double helix structure and is mostly deoxyribose sugar?

DNA

What is the primary function of messenger RNA (mRNA) in the cell?

Transferring genetic information from DNA to the ribosome

Which molecule contains a complex tertiary structure, especially in transfer RNA (tRNA)?

tRNA

What is the universal flow of genetic information as per the Central Dogma of Molecular Biology?

From DNA to RNA to proteins

Which of the following contains nucleosomes and various fiber sizes and carries genes?

Homologous chromosomes

What are the units of heredity that contain instructions for an organism's phenotype?

Genes

What process creates mRNA from DNA in the cell?

Transcription

Study Notes

Homologous chromosomes: maternal and paternal carry genes, have key structures like telomeres and centromeres, and differ in size and number of exons/introns.
Chromosomes: made up of a double helix of DNA, nucleosomes, and various fiber sizes, carry genes.
Genes: units of heredity, contain instructions for an organism's phenotype, are made up of exons and introns, and come in different sizes and numbers of exons/introns.
Central Dogma: transcription creates mRNA from DNA, and translation produces proteins from mRNA, using different languages of nucleic acid.
DNA and RNA: both nucleic acids, but DNA has deoxyribose sugar and double stranded structure, while RNA has ribose sugar and is mostly single stranded.
DNA structure: composed of nitrogenous bases, deoxyribose sugar, and phosphate groups, forms base pairs through hydrogen bonding, and has specific ratios of bases.
RNA: comes in various types, including messenger (mRNA), transfer (tRNA), ribosomal (rRNA), small nuclear (snRNA), small nucleolar (snoRNA), and small cytoplasmic (scRNA), and plays a role in protein synthesis and gene expression.
DNA vs RNA: DNA forms a double helix and is mostly deoxyribose sugar, while RNA is mostly ribose sugar and is single stranded, except in some viruses.
RNA structure: has a secondary structure with stems and loops, and a complex tertiary structure, especially in transfer RNA (tRNA).
Central Dogma of Molecular Biology: genetic information flows from DNA to RNA to proteins, and the genetic code is universal to all organisms.
Genome: the entire complement of DNA molecules in an organism, controls the generation of proteins and regulates metabolism and response to the environment.