W1-3 Comprehension Quiz Flashcards
Define Adenine
One of the 4 nitrogen bases associated with DNA. It is a purine that consists of 2 rings and matches with Thymine (AT) with 2 hydrogen bonds. It’s the weaker of the bases.
Define Allele
Different versions of a gene (normal or mutated)
Define Amino Acids
compounds found in living cells. Ex: oxygen, carbon, and hydrogen and nitrogent join together and form proteins.
Define Anneal
To attach. Example, primers anneal to DNA strands during PCR
Define Autosome
chromosomes 1-22 for humans. The non-sex chromosomes
Define Base Pairs
In the DNA structure, base pairs are AT or GC. Base pairs is how DNA is measured. (ex. 30 bps long means 30 base pairs). FUN FACT : It takes 10 base pairs to make a turn in the DNA double helix
Define Centromere
The “pinched” region along the chromosome that separates it into two arms. The can be located in the middle of the chromosome, or can be situated closer to the end of the chromosomes. The centromere is composed of a protein belt that functions as an attachment site for pulling two chromosomes apart during cell division
Define Condensed Chromosomes
DNA that has been tightly packed by condensin and resembles an X.
Define Condensin
The additional packing and coiling. A protein that helps DNA condense into chromosomes before the start of cell division.
Define Covalent Bond
A chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.
Define Crossing Over
When chromosomes overlap, genetic material from one chromosome can trade places with genetic material from the other.
Define Cytosine
One of the 4 nitrogen bases associated with DNA. It is a pyrimidine that consists of 1 ring and matches with Guanine with 3 hydrogen bonds.
Define Denature
A process by which DNA double strands separate into single strands. This generally happens at very high temperatures.
Define Diploid
A cell with two chromosome copies.
Define Duplicated Chromosomes
The X-like structure that we commonly associate with chromosomes is actually a duplicated chromosome, where the chromosome has been copied and the two copies are held together at the centromere.
Define Exons
Remaining stretches of a DNA sequence that are spliced together and sent off to make proteins. They are the expressed parts. These sequences are called exons because they are the expressed sequence.
Define Expression
When a gene has been activated or turned on so its protein product is made.
Define Gametes
Sperm and Egg cells. A mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote.
Gene
The short sequence of DNA that carries the sequence information to make the many proteins needed by the cell. It shows our traits
Guanine
One of the 4 nitrogen bases associated with DNA. It is a purine that consists of 2 rings and matches with Cytosine with 3 hydrogen bonds.
Haploid
A cell with only one set of chromosomes. An egg or a sperm is an example of a human haploid cell.
Define Helicase
The enzyme that unwinds and separates DNA during replication and creates replication forks.
Define Histone
The process of being tightly packed and folded
Define Homologous chromosomes
Non sex chromosomes
Define Hydrogen bond
The weaker of the two bonds. AT. The electrostatic attraction between polar groups that occurs when a hydrogen (H) atom bound to a highly electronegative atom such as nitrogen (N), oxygen (O) or fluorine (F) experiences attraction to some other nearby highly electronegative atom.
Define Introns
Long stretches of DNA that are removed before being read for protein manufacture. These sequences are called introns because they are the intervening sequence.
Define Ionic Bond
chemical bond that uses electrostatic attraction and interacts with ionic compounds.
between oppositely charged ions, and is the primary interaction occurring in ionic compounds. The ions are atoms that have lost one or more electrons (known as cations) and atoms that have gained one or more electrons (known as anions).
Define Karyotype
Used under a microscope to tell when the cell is in the process of dividing. A karyotype is the number and appearance of chromosomes in the nucleus of a eukaryotic cell. The term is also used for the complete set of chromosomes in an individual organism. Karyotypes describe the chromosome count of an organism and can be seen under a light microscope when the cell is in the process of dividing.
Define Lagging Strand
The lagging strand replicates in small segments called Okazaki fragments. These fragments are stretches of 100 to 200 nucleotides in humans (1000 to 2000 in bacteria) that are synthesized in the 5’ to 3’ direction away from the replication fork. Yet while each individual segment is replicated away from the replication fork, each subsequent Okazaki fragment is replicated more closely to the preceding replication fork than the fragment before. These fragments are then stitched together by DNA ligase, creating a continuous strand.
Define Leading Strand
The strand during DNA replication that is replicated from the 5’-3’ continuously.
Define Meiosis
The process of cell division in sexually reproducing organisms that reduces the number of chromosomes from diploid to haploid, as in the production of gametes.
Define Nucleic Acid
complex compounds found in living cells and viruses, made of purines (A,G) , pyrimidines (C,T) , carbohydrates, and phosphoric acid. Nucleic acids in the form of DNA and RNA control cellular function and heredity.
Define Nucleotide
they form the basic structural unit of nucleic acids such as DNA. a group of molecules that, when linked together, form the building blocks of DNA or RNA: in DNA the group comprises a phosphate group, the bases adenine, cytosine, guanine, and thymine, and a pentose sugar.a compound consisting of a nucleoside linked to a phosphate group. Nucleotides form the basic structural unit of nucleic acids such as DNA.
Define Okazaki fragments
Fragments on the Lagging Strand during DNA Replication because the DNA Polymerase can only add nucleotides from the 5’ end and this causes discontinuous fragments. This is one of the easiest ways to tell if this is a lagging strand instead of a leading strand.
Define Primase
Synthesizes RNA primer at the replication fork prior to DNA Polymerase.
Define Primer
A short strand of nucleotides that matches the DNA strand to be replicated.
Define Protein
A complex compound found in all living cells made of amino acids.
Define RNase H
Recognizes primers and removes them from DNA strand during DNA replication.
Define Random Alignment
This happens during metaphase I which allows equal opportunity for a particular chromosome to migrate into a cell.
Define Reagent
A substance used to detect, measure, examine, or produce other substances.
Define Recombinase
- An enzyme that encourages the exchange of short pieces of DNA between two long DNA strands, particularly the exchange of homologous regions between the paired maternal and paternal chromosomes during crossing-over.
Define Replication
The process by which cells copy DNA.
Define SSB protein
(Single strand binding protein) keeps the DNA strands separated during the replication process.
Define Satellite Regions
Stretches of DNA that exist between genes, or are found within a single gene between exons. often referred to as junk dna
Define Sex Chromosome
– The chromosomes that determine the gender of the species.
Define Sister Chromatids
- Two identical copies of a single replicated chromosome that are connected by a centromere.
