unit 2 Test Flashcards
What is the overall purpose of meiosis? What is the product of meiosis?
reduces the number of chromosomes in the parent cell by half and produces four gamete cells. This process is required to produce egg and sperm cells for sexual reproduction.
How much genetic information is in the cells after meiosis has been completed?
half the genetic material in each new gamete cell
Describe the places where genetic variation occurs during the process of meiosis and fertilization.
Genetic variation occurs during crossing over, independent assortment and random fertilization.
(Crossing over, Independent assortment, Random fertilization)
What evolutionary advantage is there to create genetic variation through the process of meiosis?
it strengthens the ability of species and populations to resist diseases, pests, changes in climate and other stresses. Gene variations underpin their capacity to evolve and their flexibility to adapt.
What is fertilization and what is the result of this process?
Fertilization is the fusion of an egg and a sperm cell (or seed and pollen in plants) that are both haploid cells. The result is a zygote that is a diploid cell.
What happens to a cell once it has been fertilized?
-cell goes through the process of mitosis and starts to copy several cells.
-after they become differentiated where the cells become specialized and have special roles and functions.
What are the basic building blocks of DNA?
The basic building blocks of DNA are nucleotides (phoshate, sugar and base)
ATTGCCAGTCAT
TAACGGTCAGTA
When does DNA replication occur? Why is it important to cells?
-during the S-phase in interphase of the cell cycle.
-newly replicated cells will need a full copy of DNA in order to function.
Where in the cell does DNA replication occur?
nucleus
What does DNA code for?
proteins
Describe the process of transcription. Include all steps.
-DNA separates at the bases
-The RNA nucleotides will come in and match on ONE side of the DNA (A-U & C-G)
-The RNA molecule will detach from the DNA molecule and move out tof the nucleus
What is produced at the end of transcription?
an RNA transcript
Where does transcription take place?
nucleus
What is produced at the end of translation?
A polypeptide chain made of amino acids
Where does translation take place?
ribosome.
What are the 3 types of RNA? What is the function of each of the types?
mRNA) encodes proteins
tRNA) acts as an adapter between mRNA and amino acids
rRNA) forms ribsomes
DNA template is TAC CCC AAT TGC. What mRNA sequence would be created from this DNA template?
AUG GGG UUA ACG
AUG GGG UUA ACG
MET - GLY - LEU - THR
What is a mutation?
is a mistake in the DNA where the code is changed from the original
How do mutations affect proteins?
-sometime not affect the protein at all if the same amino acid results
-Sometimes affect the structure of the protein if the amino acid is switched this sometimes also disrupts the function.
Would a mutation have more of an effect on an organism if it occurred in the DNA or in the mRNA? Why?
DNA because they are the original instructions and if the cell is replicated that mistake (mutation) is then copied to all the other cells that is a result from that copying.
Describe a situation in which a mutation is harmful and describe a situation where a mutation can be beneficial.
-harmful if it changes the function of the protein that does not support the organism’s survival.
-bring new variations that can be favorable when natural selection is involved.
