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30 Cards in this Set
- Front
- Back
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Where does DNA form?
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DNA: Forms in the nucleus
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What are chromosomes?
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DNA is organized into units/”pieces” known as chromosomes
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Chromosomes may be found unduplicated....
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...or duplicated with two sister chromatids connected at a centromere.
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Chromosomes are very long, but compact themselves by...
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...forming nucleosomes wrapped around histones.
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What is Chromatin?
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Chromatin is the combination of DNA and proteins that makes up chromosomes.
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What is diploid?
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two copies of each chromosome
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What is haploid?
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one copy of each chromosome
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How many chromosomes do humans have?
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a total of 46. Twenty-two of these pairs, called autosomes, look the same in both males and females. The 23rd pair, the sex chromosomes, differ between males and females. Females Chromosomes have two copies of the X chromosome, while males have one X and one Y chromosome.
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What are autosomes?
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A chromosome that is not a sex chromosome.
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What are sex chromosomes?
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with XX resulting in a female and XY in a male in mammals.
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What is a karyotype?
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A karyotype is the number and appearance of chromosomes in the nucleus of a eukaryote cell.
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What is a Karyotype?
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A karyotype is the number and appearance of chromosomes in the nucleus of a eukaryote cell
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What is DNA’s Function?
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Deoxyribonucleic acid (DNA) is a nucleic acid which carries genetic instructions for the biological development of all cellular forms of life and many viruses.
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What does DNA stand for?
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Deoxy ribo nucleic acid
(Deoxyribonucleic acid ) |
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Who is Johann Miescher?
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Johann Miescher is credited with the discovery of DNA in the late 1800s.
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What did Fred Griffith do?
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Griffith performed 4 experiments: Injected mice with R cells & S cells
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What did Oswald Avery do?
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and his coworkers reported in 1944 that the substance that caused the transformation was DNA, the cell's genetic material. The discovery thus opened the door to deciphering the genetic code.
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What are bacteriophages?
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Viruses called bacteriophages use bacterial cells for reproduction.
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Who were Hershey and Chase?
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They conducted a series of experiments conducted in 1952, confirming that DNA was the genetic material
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DNA is composed of....
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four kinds of nucleotides, each of which consists of: a.A five-carbon sugar—deoxyribose; b.A phosphate group; & c.One of four bases—adenine (A), guanine (G), thymine (T), orcytosine (C).
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What is a nucleotide?
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Nucleotides are little components that make up DNA, and they are connected by phosphate molecules.
The nucleotides are similar, but T and C are single-ring pyrimidines; A and G are double-ring purines. |
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Who were James Watson and Francis Crick (1950’s)?
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They worked together discover the makeup of DNA, the genetic code of life. In 1953 they came up with the double-helix model
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Who was Rosalind Franklin?
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She did X-ray studies of molecules that played a crucial role in the discovery of the structure of DNA
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What is DNA’s Base Pair Sequence?
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two nucleotides on opposite complementary DNA or RNA strands that are connected via hydrogen bonds are called a base pair. In base pairing, adenine (A) forms a base pair with thymine (T), as and guanine (G) with cytosine (C) in DNA.
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How does DNA get copied?
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two strands of DNA unwind and expose bases. a.-Then, unattached nucleotides pair with exposed bases. T-A; G-C
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What is DNA helicase?
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DNA helicase unwinds the two nucleotide strands.
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What is DNA polymerases?
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DNA polymerases “proofread” the new bases for mismatched pairs, which are replaced with correct bases.
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Errors that are NOT fixed are called.....
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Mutations
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What is cloning?
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Cloning is a laboratory method of making multiple copies of DNA.
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What is Embryo cloning?
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Embryo cloning is a natural occurrence producing identical twins.
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