Cell Division, Genetics, and DNA: Key Concepts
Key Concepts in Cell Division
– Structure that holds two chromatids together is:
b) Centromere
– In multicellular organisms, mitosis results in:
b) Growth and repair of tissues
Each of the two duplicated strands of a chromosome is called a:
a) Chromatid
What is the role of the spindle during mitosis?
a) The spindle fibers help to push and pull the chromosomes to separate them.
All of the following are problems that are faced by a cell that is growing too large, EXCEPT:
d) Too much oxygen entering the cell.
Method of eukaryotic cell division that results in daughter cells that are genetically identical to the parent cell.
a) Mitosis
Method of eukaryotic cell division that results in daughter cells that contain half the genetic information of the parent cell.
b) Meiosis
Cells formed by meiosis are:
b) Reproductive cells.
Essential Terms in Cell Biology
- Mitosis: Division of the nucleus
- Chromatid: One of two identical “sister” parts of a duplicated chromosome
- Interphase: The period of growth in between cell divisions
- Cell cycle: A series of events that cells go through as they grow and divide
- Cell division: It solves the problems of overloading DNA and not being able to get enough materials in and out
- Cyclin: Internal regulator of the cell cycle
- Growth factor: External regulator of the cell cycle
- Cytokinesis: Division of the cytoplasm
Fundamental Concepts of Genetics
What is an allele?
An alternative form of a gene
The type of allele that is always expressed if present is:
Dominant
What is the term for having both alleles of a gene being the same?
Homozygous
Heterozygous refers to:
Having different alleles of a gene
What term describes the genetic information an organism possesses?
Genotype
The physical characteristics displayed by an organism are known as:
Phenotype
Which principle states that genes for different traits can segregate independently when gametes are made?
Principle of independent assortment
If alleles have codominance…
Both alleles’ phenotypes show up at the same time
What is meant by multiple alleles?
A gene with more than two alleles
Which traits are controlled by genes found on the sex chromosomes?
Sex-linked traits
DNA Structure, Replication, and Mutations
DNA is composed of subunits called:
a) Nucleotides
The process by which DNA makes an exact copy of itself is called:
d) Replication
Which nitrogen base forms a bond with cytosine?
d) Guanine
What is the name of the sugar found in DNA?
b) Deoxyribose
Enzyme that unzips DNA like a zipper on a coat, creating two single strands of DNA:
a) Helicase
Enzyme that creates a starting point for DNA polymerase.
c) Primase
Enzyme that joins the new DNA strands together.
d) Ligase
Builder enzyme that synthesizes new strands of DNA, adding nucleotides.
b) DNA Polymerase
What is the function of DNA in cells?
b) It stores the information that directs the ribosomes in protein synthesis.
Which of the following would not be found in a nucleotide?
c) DNA polymerase
Which of the following bases is never found in DNA?
b) Uracil
Types of DNA Mutations
- A change in the DNA sequence: Mutation
- Replacing a nucleotide with a different nucleotide: Substitution
- Removing a nucleotide: Deletion
- Adding a nucleotide: Insertion
- Mutation that shifts the reading frame of codons: Frameshift mutation
- Mutation that changes one amino acid in the protein: Missense mutation
- Mutation that does not change the protein: Silent mutation
- Mutation that inserts an early STOP codon: Nonsense mutation