Biology › Understanding Chromosomes and Genes
A genome is best described as which of the following?
The entire set of DNA found within all chromosomes
The free floating DNA found outside the nucleus
The DNA specifically found in bacterial cells
A mapping unit for DNA
A computer system for storing DNA information
Based on the definition of genome, it is the entire set of DNA found within all the chromosomes an organism contains. The human genome is contained on 23 pairs of chromosomes, which code for about 25,000 genes.
How can synteny help with understanding chromosomes?
It can indicate conserved regions
It can indicate crossover events
It can indicate recombination events
It can indicate hybridization
It can indicate recessive neofunctionalization
Synteny is the conservation of order of genes. Being able to see conserved blocks in genes when comparing two chromosomes of the same species, it indicates that at some time in evolutionary history, these blocks originated from a hypothetical common ancestor. Genes that are highly conserved among species are usually vital to the organism's viability. For example, the genes required for glycolysis to occur are required in almost all organisms.
Which of the following is/are example(s) of nucleic acids?
Two of these answers are correct
DNA
rRNA
Glucose
Cholesterol
Nucleic acids include DNA and all forms of RNA (mRNA, tRNA, rRNA, and htRNA). Note that the different types of RNA have the same base structure, but serve different functions. Messgener RNA (mRNA) is used as the template for protein translation. Transfer RNA (tRNA) transports amino acid residues to the ribosome during translation to aid in polypeptide elongation. Ribosomal RNA (rRNA) is used to form the structure of the ribosomal subunits. Heternuclear RNA (htRNA) is the original product of transcription, and is found in the nucleus prior to post-transcriptional modifications.
Glucose is a carbohydrate, and cholesterol is a lipid.
Operons __________.
are sets of genes that are often regulated together
are only found in eukaryotes
often involve multiple chromosomes
are always involved in protein synthesis
More than one of the other answer choices is correct.
An operon is a segment of DNA that is under the control of a single promoter. For example, if there are three genes required for breaking down a sugar in an operon, they will all be activated together. This makes sense, as there is no sense in activating only one or two of these genes, since all three are required to break down the sugar. For example, the control element that turns on the operator can be the sugar itself. It should make sense that the genes required to break down a sugar are only turned on if that sugar is present.
Which of the following answers best describes the human genome.
The human genome consists of approximately 3.2 billion base pairs, has 23 (pairs of) chromosomes, and approximately 25,000 genes. The chromosomes are arranged end to end along the contiguous DNA strand. Genes are much shorter segments within the chromosomes and can be transcribed into mRNA. Messenger RNA is then translated into protein.
The human genome consists of approximately 3.2 billion base pairs, has 23 (pairs of) chromosomes, and approximately 25,000 genes. The genes are arranged end to end along the contiguous DNA strand. Chromosomes are much shorter segments within the genes and can be transcribed into mRNA. Messenger RNA is then translated into protein.
The human genome consists of approximately 3.2 billion base pairs, has 23 (pairs of) chromosomes, and approximately 25,000 genes. The chromosomes are arranged end to end along the contiguous DNA strand. Genes are much shorter segments within the chromosomes and can be translated into mRNA. Messenger RNA is then transcribed into protein.
The human genome consists of about 3.2 million base pairs and it has 23 (pairs of) chromosomes of equal length with widely varying numbers of genes. The genes can be transcribed into mRNA and then translated into protein.
The human genome consists of about 3.2 million base pairs and it has 23 (pairs of) genes of equal length with widely varying numbers of chromosomes. The chromosomes can be transcribed into mRNA and then translated into protein.
The human genome can be described as a chain of nucleotides that is 3.2 billion base pairs long. Twenty-three different lengths that are called chromosomes segment this string of material. Genes further segment the chromosomes. The chromosomes vary in length and so do their genes. DNA of a gene on a certain part of a certain chromosome can be transcribed into mRNA, which is then translated into protein. The number of genes in our genome has been highly contested. It was originally believed that humans had over 100,000 genes. This number declined as we learned more about our genome and was more or less standardized to be around 25,000 upon completion of the Human Genome Project.
Which of the following contains and controls the use of DNA?
Chromosomes
Genes
Cytoplasm
Chromatin
Nucleus
During most of the cell cycle, DNA is found as chromatin. Chromatin is a mass of DNA and associated proteins. Depending on the state and activation of those proteins and on how tighly packed the DNA is around the proteins, certain genes can be turned on or off.
Chromosomes form from condensed chromatin only during mitosis (specifically during prophase), and are absent during most of the cell's cycle. Genes are units of heredity that encode the information needed to specify the amino acid sequence of proteins. The gene is the functional segment of DNA located at a specific place, or locus, on a chromosome. The cytoplasm is the material contained in the cell membrane and outside the nucleus. The nucleus is a membrane-bound organelle that contains the cell's genetic material.
The correct pairing of nucleotide bases in DNA are __________.
cytosine with guanine and adenine with thymine
cytosine with guanine and adenine with uracil
cytosine with adenine and guanine with thymine
cytosine with thymine and guanine with adenine
The nucleotides in DNA always pair the same way; A with T and G with C. This is due to the chemical structure of each base; adenine and thymine form two hydrogen bonds when pairing, and guanine and cytosine form three. The other important thing to remember is that there is a different nitrogen base in RNA called uracil; uracil is not found in DNA, so pay attention to which molecule the question is asking about.
A chromosome is a molecule of __________.
DNA
RNA
Protein
Carbohydrate
A chromosome is one molecule of DNA. It contains genetic information required for cell replication and the passing down of genetic information. Humans have 23 pairs of chromosomes, with one chromosome per pair from the mother, and the other from the father.
Genes are said to be expressed when they are __________.
transcribed and translated
replicated
deleted
copied into another strand of DNA
inserted into the ribosome
Genes are expressed when their gene products are made, to do this transcription and translation must occur to synthesize the protein which is coded for by the DNA.
DNA is found in which of the following?
Chromosomes
Proteins
RNA
Amino acids
DNA—deoxyribonucleic acid—is found in chromosomes within a cell’s nucleus. A complete set of DNA (i.e. 46 chromosomes) is called a genome. DNA contains instructions that make humans different from other species and other individuals. DNA provides instructions for all the proteins that the body makes and is passed from adults to offspring. DNA cannot get out of the nucleus; however, RNA can. RNA is used to get the instructions from DNA out of the nucleus and into the site of protein synthesis: the ribosomes within the cytoplasm. Proteins are made of amino acids and determine the structure and function of all of the body’s cells.