Biology 9 Flashcards
What is cell theory
Who are the 3 discoverers of cell theory?
The basic principles of biology
Theodor Schwann, Matthias Schleiden, Rudolph Virchow
What can cells be
Unicellular or multicellular
Red blood cells have no nucleus
True
Most important function of a cell
Produce proteins
What are proteins and what are they made up of
Biological molecules, made up of amino acids
Examples of amino acids
Hemoglobin, insulin, keratin, collagen, enzymes
How do you calculate field of view
Low power f.o.v x magnification of low power / magnification of medium power
Nucleus
Most visible component of a cell (controls everything
Nuclear membrane
A barrier to what can eneter/exit
Nuclear pores
Allows ribosomes and RNA to exit the nucleus
Chromatin
Material inside the nucleus that’s composed of unraveled chromosomes containing DNA
Nucleolus
Visible part, responsible for production of ribosomes to be transported outside the nucleus to the rough ER
DNA
Deoxyribonucleic acid
Blue print for the body
Nucleotides
Basic unit of DNA
What are nucleotides made up of
One sugar and phosphate molecule and one of the four nitrogen bases
4 nitrogen bases
Adenine, thymine, cytosine, guanine
A-T, C-G
Nucleotide diagram
Rectangle (phosphate) - house (sugar) - circle (base)
Double helix
Double stranded molecule (twisted ladder)
Covalent bonds
Hold atoms together
Hydrogen bonds
Hold two strands of the spiral together (weak)
Genes
Segment of DNA that codes for a protein (determined by bases)
Responsible for all characteristics
Genome
Organisms genes
Human genome is contained in the….
23 chromosomes in the nucleus
DNA Replication (Steps)
Unwind - base pairing - joining
DNA Replication
DNA unzips when it splits- if you know the bases of one strand then you know the other
DNA replication enzymes
Polymerase- helps new bases join old
Helicase- separates DNA
Genes store all the information needed to produce how many proteins
10,000 to 90,000
RNA
Ribonucleic acids
Single stranger
What sugar does RNA contain
Ribose
3 types of RNA
mRNA, tRNA, rRNA
Four base pairs of RNA
Adenine, cytosine, guanine, Uracil
A-U, C-G
Chromosomes
Made up of one strand of DNA, two chromatids paired
Chromatid
A copy of the chromosome after it has replicated
Centromere
The regions where chromatids are attached
What do chromosomes determine
Sex of a person (M = Y, F= X)
What are each chromosomes paired with
Another chromosome that has the same genetic information
Cell division: functions
Growth, repair, reproduction
What happens in the growth phase of cell division
Organisms begin as a single cell (multicellular cells go through cell division to increase)
Cytoplasm increases
Cells specialize and grow tissues/organs when a body gets enough cells
What happens in the repair phase of cell division
Multicellular cells can become damaged
What happens in the reproduction phase of cell division
Unicellular cells use cell division
Single celled bacteria reproduce (identical copies)
Cell cycle phases
Interphase, mitosis, cytokinesis
What happens in interphase
Growth phase
Cells synthesize proteins
DNA copies itself
Four phases of interphase
G0: cells are always resting
G1: Growth in cell
S: DNA replication
G2: Further growth
What happens in mitosis
Nucleus division
DNA movement is caused by spindle fibers
What happens in cytokinesis
Cell divides
Daughter cells
4 phases of mitosis
Prophase
Metaphase
Anaphase
Telophase
What happens in prophase
First stage- chromosomes “coil”, nuclear membrane disappears, centrioles divide and move to opposite poles