Bio Test ch. 12/13/15

DNA & RNA are what kind of macromolecules?

Nucleic acids

What causes genetic disorders?

mutations

What is the significance of protein synthesis in all living cells?

To make proteins to code DNA

What instructions do genes contain?

Tell your cells to make molecules based on physical features

What is a gene?

The basic unit of heredity passed from parent cell to daughter cell

What determines an organism’s genetic code?

DNA: adenine (A), cytosine (C), guanine (G) and thymine (T)

What is a nucleotide?

nitrogenous base, a pentose sugar and a phosphate.

What 3 parts make must be present to make a nucleotide?

nitrogenous base, a pentose sugar and a phosphate.

What is the shape of DNA?

Double helix

What makes up the sides of the DNA?

deoxyribose sugars

What makes up the rungs of DNA?

alternating with phosphates (adenine (A), cytosine (C), guanine (G) and thymine (T) )

What is protein synthesis?

process of creating protein molecules

What does Thymine always pair with?

Adenine

What does Guanine always pair with?

Cytosine

What are the bases of DNA?

adenine (A), cytosine (C), guanine (G) and thymine (T)

What are the bases of mRNA?

adenine (A), uracil (U), guanine (G), and cytosine (C)

What are the bases of RNA?

adenine (A), uracil (U), guanine (G), and cytosine (C)

What joins the bases together?

Hydrogen bonds

What enzyme “unzips the DNA molecule before replication?

Helicase

Avery conducted a series of experiments that showed that _____ is responsible for transformation.

bacterial transformation

What is replication?

the process by which the genome's DNA is copied in cells

What does DNA replication result in?

two DNA molecules consisting of one new and one old chain of nucleotides

What is a mutation?

Any change in the DNA sequence of a cell.

### What is a codon?

a sequence of three nucleotides which together form a unit of genetic code in a DNA or RNA molecule.

What is the name of the sugar found in DNA?

deoxyribose sugar

What is the name of the sugar found in RNA?

ribose sugar

How does RNA differ from DNA?

DNA is a double-stranded helix, RNA is single-stranded

What is transcription?

the process by which a cell makes an RNA copy of a piece of DNA

What is translation?

the process by which a cell makes proteins using the genetic information carried in messenger RNA

What base is different in RNA compared to DNA?

uracil (U) and thymine (T)

What kind of RNA makes up ribosomes?

messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA)

What organelle does mRNA attach to?

ribosome

Which RNA molecule is shaped like a cloverleaf?

tRNA molecule

Why is tRNA molecules important?

role in protein synthesis

DNA serves as a template for making what?

RNA molecule

Arrange these from smallest to largest: DNA, nucleotide, nucleus, cell, chromosome

DNA, nucleotides, chromosome, nucleus, cell

Where is DNA located in the cell?

In the nucleus

Where is RNA located in the cell?

Ribosomes and in the cytoplasm

What is a mutagen?

Anything that causes a mutation (a change in the DNA of a cell)

Examples of mutagens.

radioactive substances, x-rays, ultraviolet radiation, and certain chemicals.

What is a point mutation?

a mutation affecting only one or very few nucleotides in a gene sequence.

What is a frameshift mutation?

he insertion or deletion of nucleotide bases in numbers that are not multiples of three

How many nucleotides are affected by point mutations?

1

How many nucleotides are affected by frameshift mutations?

all of them after the mutation

Why are few mutations passed on to the next generation?

traits are passed only from the sperm and egg.

What can some mutations in body cells result in`?`

Genetic conditions like cancer, or they could help humans better adapt to their environment over time.

What is the function of the “proofreader” enzymes?

allows the enzyme to check each nucleotide during DNA synthesis and excise mismatched nucleotides

Where does transcription occur in the cell?

nucleus

Where does translation occur?

ribosomes

Which scientists were the first to suggest that DNA is the shape of a double helix?

James Watson and Francis Crick

What mutations are less severe?

point mutation

What happens during the deletion of chromosomal mutation?

chromosome breaks and some genetic material is lost

What happens during the insertion of chromosomal mutation?

addition of one or more nucleotides into a segment of DNA

What happens during the inversion of chromosomal mutation?

segment breaks off and reattaches within the same chromosome, but in reverse orientation

What happens during the translocation of chromosomal mutation?

a segment breaks off and reattaches within the same chromosome, but in reverse orientation

In order for a mutation to be passed on to its offspring, the mutation would have to occur in the organism’s _____.

eggs and sperm cells

What do “codons” code for?

A specific amino acid.

What makes up chromosomes?

proteins and DNA organized into genes.

DNA must unzip in order for what 2 processes to occur?

mitosis and meiosis.

Who found that when a virus attaches itself to a bacterium, it injects DNA into the bacterium?

Hershey and Chase

Sickle-cell anemia is an example of a ______ mutation.

Transversion

Anticodons are found on ______ molecules

tRNA

For what type of product does an intron code?

rRNA

What are exons?

Region of the genome that ends up within an mRNA molecule

What are introns?

a segment of a DNA or RNA molecule which does not code for proteins and interrupts the sequence of genes.

What do extrons code for?

part of the RNA that code for proteins.

What kind of bonds form between the amino acids in making a protein?

peptide bonds

What does tRNA do after it has released its amino acid?

bind to another molecule of the amino acid and be used again later in the protein-making process

Who demonstrated, using strains of pneumonia bacteria, that the transforming factor in cells was DNA?

Frederick Griffith

what did Martha Chase show?

that DNA is the molecule that carries genetic information

Who used x-ray crystallography to reveal the structure of DNA?

Rosalind Franklin

What does a virus do when it attaches itself to a bacterium?

employ a 'tail' that stabs and pierces the bacterium's membrane to allow the virus's DNA to pass through

Which 2 scientists showed the fibers of DNA to be twisted through x-ray pattern?

Wilkins and Franklin

Describe transcription of the DNA instructions to RNA.

a strand of mRNA is made that is complementary to a strand of DNA

Describe the role of mRNA in translation.

as the decoding of instructions for making proteins

Explain the function of tRNA in transcription.

Carry protein information from the DNA in a cell's nucleus to the cell's cytoplasm

How to change DNA to RNA?

copying a gene's DNA sequence to make an RNA molecule

How to change mRNA to tRNA?

matching tRNA codon next to each mRNA codon and linking the amino acids before ejecting the tRNA

How to find the amino acid?

Use the mRNA to find the amino acid

What is selective breeding?

choosing parents with particular characteristics to breed together and produce offspring with more desirable characteristics

What is inbreeding?

breed from closely related people or animals, especially over many generations.

What are eugenics?

Eugenics is a fringe set of beliefs and practices that aim to improve the genetic quality of a human population.

What are epigenetics?

study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself.

What are the functions of proteins?

acting as enzymes and hormones, maintaining proper fluid and acid-base balance, providing nutrient transport, making antibodies, enabling wound healing and tissue regeneration, and providing energy

How did Rosalind Franklin contribute to the discovery of DNA?

creation of the famous Photo 51 demonstrated the double-helix structure of deoxyribonucleic acid

What is genetic engineering?

the deliberate modification of the characteristics of an organism by manipulating its genetic material.

What is the Human Genome Project?

ambitious research effort aimed at deciphering the chemical makeup of the entire human genetic code

What is the Human Genome Project’s goal?

to decipher the chemical sequence of the complete human genetic material (i.e., the entire genome)

How is the human genome sequenced?

Sequencing samples collected from a small number of individuals and then assembling the sequenced fragments

What is the purpose of gene therapy?

to treat or cure disease

What is gene therapy?

the transplantation of normal genes into cells in place of missing or defective ones in order to correct genetic disorders.

What are Hox genes?

a group of related genes that specify regions of the body plan of an embryo along the head-tail axis of animals.

What do Hox genes determine?

anterior-posterior body axis in bilateral organisms

Why are point mutations less severe?

they only affect one amino acid