Section-4; Genetics Flashcards
identify the stages of cell division.
(Interphase), Prophase, Metaphase, Anaphase, Telophase. PMAT.
define cell division
a process in which a cell divides into two new daughter cells.
distinguish between G1, S, and G2.
G1- the period prior to the synthesis of DNA. Cell increase in mass in preparation for cell division.
S- the period in which DNA is synthesized.
G2- the cell synthesizes proteins ms continues to increase in size.
explain the difference between interphase, mitosis and cytokinesis.
During telophase, the last stage of mitosis, the chromosomes have reached the poles and they begin to uncoil and become less condensed. Two new nuclear envelopes begin to form around each of the two separated sets of unreplicated chromosomes. At the same time, there is division of the cytoplasm (cytokinesis)
Which type of cell division, mitosis or meiosis contributed to the genetic variation among humans?
Meiosis(crossing over and variations)
explain the stages of mitosis (you should know what this looks like too)
Prophase- Chromatin condenses into chromosomes. Nuclear envelope disappears.
Metaphase- Chromosomes align at the equatorial plate.
Anaphase- Sister chromatids separate. centromeres divide.
Telophase-Chromatids expands. Cytoplasm divides.
define haploid
cell that contains one complete set of chromosomes.
define diploid
cell that contains two sets of chromosomes
differences between human body and sex cells?
the human body has 46 chromosomes and sex cells have 23 chromosomes.
cytokinesis in plant cells vs. animal cells
animal cell- the cell membrane is drawn inward until the cytoplasm is pinched into two equal parts.
plant cell- a cell plate forms.
difference between mitosis and meiosis?
After mitosis, each of the daughter cells will have the exact same DNA strand while after meiosis each daughter cell will have half of the DNA strands.
define gametes
A sex cell, either sperm or egg, capable of fusing with another gamete of the opposite sex to form a fertilized egg(not if you use a condom!)
explain crossing over
sister chromosomes line up during the early stages of meiosis 1, segments of DNA may be moved from one chromosome to another when the two strands overlap. allows for variation in offspring
define genetics
scientific study of heredity
Explain the base pairing rules
Adenine to Thymine (A-T)
Cytosine to Guanine (C-G)
What shape is DNA?
double helix
distinguish between replication, transcription and translation.
transcription transfers the genetic code from a molecule of DNA to an RNA molecule. It involves the production of an mRNA molecule. The process starts after the two strands of DNA molecule separate and then one of the strands becomes a pattern for the mRNA molecule. The individual molecular strands then link together to form a strand of mRNA. Translation takes place after transcription of the genetic code into mRNA has been started. The code information must be translated into the four bases found in the mRNA.
Where does DNA replication take place in the cell?
nucleus
Why is DNA replication necessary?
forms new DNA which is needed to produce new cells through mitosis for growth and repair.
What is the complementary strand for the following DNA strand?
GTTCAG
CAAGTC
characteristics of DNA
double stranded
deoxyribose sugar
thymine as a base
stuck in the nucleus.
characteristics of RNA
single stranded
ribose sugar
uracil
three kinds; mRNA, rRNA, tRNA
What are the major steps to protein synthesis?
DNA transcribes into mRNA, the mRNA travels to the ribosome where rRNA is found. on the ribosome the mRNA is divided into codons an the tRNA will bring in the anticodon. Attached to the tRNA is the amino acid. As the amino acids bond together via peptide bonds the polypeptide bond is formed. when a stop codon is reached the protein is released.
what is the job of tRNA?
The tRNA will bring in the anticodon and the amino acid to assemble the polypeptide chain.