Chapter 7 Flashcards
Cell growth depends on what?
Using genetic information in DNA to make structural and functional proteins ( needed for survival)
What does cell reproduction ensure?
That genetic information is passed from one generation to the next
What does DNA CONTAIN?
Genetic information that determines expression of heritable traits
What does the structure of DNA resemble?
A long spiral staircase referred to as a double helix
What are the parts (building blocks) that make up DNA
Sugar and phosphate unit make the ‘ladder’
Base pair make the steps
What is the combination pairing in DNA called?
Complementary or obligatory base pairing
What is a gene?
A specific segment or sequence of base pairs within a DNA molecule
What do genes dictate and direct?
Direct the formation of enzymes and other proteins
Direct the RNA production and protein synthesis
In different chromosomes the genetic sequence _____
Varies
How many approx base pairs in human gene?
1000 base pairs
Composition of RNA
Sugar
Phosphate and nitrogenous base
What is the coding rna
mRNA
What a are the two non coding RNA
- tRNA and rRNA
_______ plays are in transcription and translation
RNA
Where does the transcription occur
Nucleus
Describe Transcription
Double strand unzips by RNA polymerase
single stranded m RNA forms along a segment of one strand of the unzipped DNA
mRNA is edited and move into cytoplasm
Describe translation
After leaving the nucleus and being edited, mRNA associates with a ribosome (which contains rRNA) in the cytoplasm
tRNA molecules then bring specific amino acids to the mRNA at the ribosome; the type of amino acid is determined by 3-base pair sequences called codons on the mRNA and anticodons on the tRNA
•As amino acids are brought into place, peptide bonds join them, resulting in the creation of a polypeptide chain aka protein
Newly formed cells….
Produce a variety of molecules and other substances required for growth/ maintenance by using the info contained in the DNA’s genes
WHEN A CELL IS NOT ACTIVELY DIVIDING IT IS IN
Interphase
The stages of interphase are called
G1, S and G2
Before a cell can decide it has to ______
Make a copy of its DNA so that it can be equally shared with daughter cells
DNA replication results in
2 whole molecules identical to the original molecule
Proceeding mitosis the DNA ______
Unwinds, separates base pairs and then each side attracts a lose complementary base pair. Making identical to start
What is mitosis
The process in cell division that distributes identical chromosomes to each new daughter cell
Mitosis enables ______
Cell to identically reproduce their own kind
What are the 4 stages of mitosis
Prophase, metaphase, Anaphase and telophase
Discuss the change of chromatins in prophase
Chromatin granules become organized to form chromosomes
- Chromosomes form a pair of linked strands called chromatids
- Chromatids are held together by a beadlike structure called a centromere
What happens with the centrioles in prophase
They move to opposite ends and spindle fibres for between them
What happens to the nuclear envelope in prophase
It disappears
What are 4 notable things of metaphase
●The nuclear envelope and nucleolus have disappeared
●Chromatids align across the center of each cell
●Centrioles have moved to opposite ends
●Spindle fibers attach themselves to the chromatids
What are 5 things worth noting in anaphase?
•Centromeres break apart
•Separated chromatids are again called chromosomes
•Chromosomes are pulled to opposite ends of cell
•Cleavage furrow develops at end of anaphase
●Beginning to divide cell into two daughter cells - cytokinesis
What are 5 things worth noting in telophase
- Cell division is completed
- Nuclei appear in each daughter cells
- Nuclear envelope and nucleoli appear
- Cytoplasm and organelles divide equally
- Daughter cells grow and become fully functional
Body cells contain how many chromosomes vs how many in mature sex cells
46 (diploid)
22 homologous pairs with 2 other (XY or XX)
Meiosis is the division of _________
Sex cells
How many chromosomes do immature cells have
Also 46
In meiosis the diploid number of chromosome is …..
Reduced to haploid (23) making the mature sex cells known as gametes
Fertilization of two gametes makes a….
Zygote
A zygote gets _____ chromosomes from each parent
23
