Bio Test 3

RNA

*also a nucleic acid *single stranded *sugar in RNA is ribose *thymine is replaced by uracil

Creating genetically modified organisms

1. Gather plasmid and target DNA 2. Cut DNA with restriction enzymes 3. Create a recombinant plasmid 4. Create transgenic cells 5. harvest product

STR (short tandem repeats)

1. because we get one chromosome from each parent, we have 2 STR sites per chromosome 2. Heterozygous: different # per chromosome 3. Homozygous: same # per chromosome

THINGS TO KNOW

1. the semi-conservative property of DNA replication reveals the process of heredity 2. DNA directs cellular functions (protein synthesis), and it contains hereditary material (genes) 3. Genetic Instructions are passed down via DNA replication 4. Gel electrophoresis sorts DNA fragments by size (length) 5. The first DNA profiling case was in England in 1983

Early analysis by the Innocence project found that around _______ of wrongly convicted individuals were wrongly convicted by hair analysis.

25%

If thymine (T) makes up 20% of the bases in a DNA double helix, what percentage of the bases is guanine (G)?

30%

Which of the following events occurs during transcription?

A molecule of RNA is formed based on the sequence of nucleotides in DNA.

Lysosome

Breaks down macromolecules using digestive enzymes

Which of the following statements is correct regarding chromosomes?

CORRECT: Chromosomes are strands of DNA, tightly wrapped up, that are located in the nucleus. INCORRECT: Chromosomes are strands of RNA, tightly wrapped up, that are in the cytoplasm. Chromosomes are strands of DNA, tightly wrapped up, that are located everywhere in the cell. Chromosomes are strands of RNA, loosely wrapped up, that are located everywhere in the cell.

In the 1950s, when Watson and Crick were working on their model of DNA, which concepts were well accepted by the scientific community?

Chromosomes are found in the nucleus. Chromosomes are made up of protein and nucleic acid. Genes are located on chromosomes.

Mitochondrion

Converts chemical fuel into packets of chemical energy (ATP) that can power the cell

Mitochondrion

Converts chemical fuel into packets of chemical energy that can power the cell

Which one of the following does not play a role in translation?

DNA

Correct the following: RNA --> protein --> DNA

DNA --> RNA --> protein

What did the structure of DNA's double helix suggest about DNA's properties?

DNA can be replicated by making complementary copies of each strand. DNA can change. Errors in copying can result in changes in the DNA sequence that could be inherited by future generations. DNA stores genetic information in the sequence of its bases.

Why does transcription occur in the nucleus and not in the cytoplasm in eukaryotes?

DNA cannot leave the nucleus.

How is DNA linked to the production of proteins?

DNA holds the instructions for the cells on how to make proteins.

Early, flawed DNA models proposed by Watson and Crick and by Linus Pauling correctly described which property of DNA?

DNA is composed of sugars, phosphates, and bases.

VOCABULARY

DNA is the self-replicating material present in nearly all living organisms; it is the main constituent of chromosomes and the carrier of genetic information. RNA is used in all steps of protein synthesis and carries the genetic information of many viruses. The nucleus is the most prominent membrane-bound organelle in eukaryotic cells, and it houses most of a cell's DNA. The nuclear envelope is the two-layered membrane that encases the nucleus of a eukaryotic cell, separating the nucleus from the cytoplasm. A protein-lined channel in the nuclear envelope that regulates the transportation of molecules between the nucleus and the cytoplasm is called a nuclear pore. The round body that sits inside the nucleus of a eukaryotic cell and makes ribosomal subunits from proteins and ribosomal RNA is known as the nucleolus. Chromosomes are tightly coiled bundles of DNA and protein found in the nucleus of most living cells.

Why is DNA analysis more sensitive than microscope hair analysis?

DNA provides more targets that can be distinguished between two individuals.

Place the following steps of DNA replication in the proper order: DNA fragments are fused together; double helix is pulled apart; new strands of DNA are synthesized.

Double helix is pulled apart, new strands of DNA are synthesized, and DNA fragments are fused together

Because bacterial chromosomes are circular, human proteins cannot be produced in bacterial cells.

False

Lysosome

Found in animal cells but not most plant cells

Nucleus

Found in both plant and animal cells

Rough ER

Found in both plant and animal cells

Cell Wall

Found in plant cells but not animal cells

Chloroplast

Found in plant cells but not animal cells

How does a scientist get the corrected version of a gene into the cells of a gene therapy patient?

It is delivered with a modified virus.

In the early 1950s, many researchers were racing to describe the structure of DNA using different approaches. Which of the following statements is true?

Jim Watson and Francis Crick built theoretical models, incorporating current knowledge about chemical bonding and X-ray data.

DNA profiling replaced an older technology for use in identifying suspects in crimes. What technology was commonly used by the FBI's Forensics Labs to identify unique characteristics of individuals prior to DNA profiling?

Microscopic Hair Analysis

Golgi Apparatus

Modifies and packages proteins

Which of the following is used to construct a molecule of DNA?

Nucleotides

You are a biochemist and have been given a test tube containing a small amount of nucleic acid. You have been asked to determine whether it is DNA or RNA. Which of the following would be a characteristic that indicates RNA? [Select all that apply.]

Presence of ribose, but no deoxyribose Presence of uracil, but no thymine

Translation converts the information stored in _______ into _______.

RNA; a protein

Which of the following mutations is LEAST likely to result in harmful changes to cellular proteins?

Silent mutation

A drug that inhibits DNA ligase but not DNA polymerase is added to a cell. Explain how DNA replication would be affected as a result of the drug.

The new DNA fragments would not be fused together and the backbone of the DNA would be incomplete

What component of DNA gives it a negative charge?

The phosphate group

Which of the following statements is incorrect regarding DNA and RNA?

They each contain a slightly different sugar molecule. DNA is double stranded, and RNA is a single strand. They are found in different locations in the cell. One of the bases is different.

PCR is used to copy just a relatively small region of DNA, not the entire genome. How do researchers specifically target the region of interest?

They use two primers, each about 15 to 20 nucleotides long, that flank the region of interest.

What is the main function of the nucleus?

To hold all of the DNA

Where does the bond form that binds one strand of DNA to its other strand?

Where does the bond form that binds one strand of DNA to its other strand?

Ribosome

Works with mRNA to synthesize proteins

Mutation

any change in the nucleotide sequence of DNA *replacing, deleting, or adding a nucleotide base can have a wide range of effects *Mutations are the raw material of evolution by natural selection *However, most mutations that we can detect are harmful

A series of three nucletodies that specifices an amino acid is a(n) __________.

codon

After DNA replication, __________.

each of the two daughter DNA molecules contains one strand from the original DNA molecule and one newly synthesized strand

Gel electrophoresis separates DNA fragments according to their ________.

length

Which of the following does not occur during RNA processing?

mRNA attaches to the small subunit of a ribosome.

Which of the following is a correct statement about mRNA?

mRNA moves from the nucleus to the cytoplasm following RNA processing.

Chloroplast

makes food by converting light energy into chemical energy

What are the chemical components of a DNA molecule?

phosphate groups nitrogenous bases sugars

Central Vacuole

regulates cytoplasm composition, creates internal pressure, and stores cell compounds

The site of translation is

ribosomes in the cell cytoplasm.

Primers

short segments of DNA that act as the starting point for DNA synthesis

Smooth ER

site of lipid synthesis

Nucleus

stores the genetic information of the cell

Plant Cell Wall

strong, protective structure made from cellulose fibrils

Which part of a nucleotide molecule in DNA encodes genetic information?

the base

PCR

the goal is to make copies of DNA segments outside of the body REACTION INGREDIENTS 1. DNA sample 2. Primers - short segments of DNA to "prime" the reaction 3. DNA polymerase to amplify DNA 4. Nucleotides to generate new strands of DNA **Using PCR, one drop of blood can provide enough DNA for analysis 1. each cycle doubles the amount of DNA 2. After 30 cycles PCR produces over 100,000,000 copies of starting DNA 3. PCR is DNA replication in a test tube

What do you call an organism that has been genetically engineered to contain a gene from a different species?

transgenic