Biology - Part 5 Flashcards
What are chromosomes and what do they consist of?
Contains genes which codes for information that specifies the production of proteins
Chromosomes consist of subunits of genes, and genes consist of DNA
What is the central dogma of biology?
DNA → RNA → Protein
What is cellular differentiation?
Differentiation produces more specialized cells from less specialized cells, and determines what cell types each cell will become
An embryo is formed when a fertilized egg divides and becomes a zygote. The most critical stage is called gastrulation, where individual tissue layers begin to form.
Genes of each cell regulate the process of differentiation.
Differentiation can occur in adults. Cells can divide and remain undifferentiated.
Do stem cells remain undifferentiated?
Yes
What is mitosis and what does it produce?
Cellular replication in which two daughter cells receive the same genetic material as the parent cell.
Makes two identical cells
2n → 2n
What is the phase that happens prior to mitosis?
INTERPHASE
G1: Preparation for DNA synthesis; Transcription & Translation
S: DNA Replication
G2: Protein synthesis and cell growth in preparation for cellular division
What does diploid mean?
2 sets of chromosomes; homologous chromosomes; all cells but gametes
2n!
What are the steps of mitosis?
See pdf
What is meiosis? What does haploid mean?
Process by which a cell ½ the genetic material
2n → 1n
Haploid (1n): 1 set of chromosomes; ONLY gametes
What is photosynthesis and what is it used for?
Both produces cellular energy for an organism
Carried out by organisms that possesses chloroplast (chlorophyll: trapping green pigment)
Used to produce ATP, which provides the energy to produce glucose from CO2 and H2O
What is the important equation for photosynthesis?
6CO2 + 6 H2O + energy → C6H12O6 + 6O2
What are autotrophs able to do?
Able to produce their own food such as plants, green algae, and cyanobacteria
What is cellular respiration?
Reverse of photosynthesis!
Glucose is broken down via glycolysis & Krebs Cycle in the mitochondria to produce even more ATP.
C6H12O6 + 6O2 -> 6CO2 + 6 H2O + energy
What are heterotrophs not able to do?
Heterotrophs are NOT able to produce their own food.
Heterotrophs rely on cellular respiration for energy
What is the first way mutations can occur in the genome?
Errors during DNA replication
During replication, DNA polymerase produces a new complementary DNA strand through base-pairing.
HOWEVER, IT DOES MAKE SPONTANEOUS ERRORS
If a mutation is OVERLOOKED, then the DNA sequence from then on is ALTERED.
Can mutations be repaired? What is mismatch repair? Excision repair?
Thus, DNA repair mechanisms exist to greatly reduce error rate!
DNA polymerase has proofreading functions
Mismatch repair: removes incorrect nucleotide and replace it with the correct one; after DNA replication
Excision repair: inspect DNA for these particular types of damage and repair it; typically it’s a section of DNA, not just a nucleotide
What is the second way mutations can occur in the genome?
Mutagens
Substances that causes DNA damage such as UV to chemicals
Mutations that occur in somatic cells are not inheritable
ONLY, ONLY, ONLY mutations in germ cells are inheritable
What are phenotypes and genotypes?
Phenotype: physical expression of genetic traits such as color, height, shape, body characteristics, etc…
Genotype: genetic make up; genes codes for particular proteins that determine the hereditary traits
What should we know about phenotypes?
BOTH genotype and environmental factors affect the phenotype of an organism.
Organisms can have different genotypes, but same phenotypes
What is a gene? What are alleles?
Gene: piece of DNA that controls a particular trait
Alleles: multiple forms of the same gene
What should we know about the Punnett square?
- *Dominant** (T) vs. Recessive (t) traits
- *Homozygous** (TT or tt) vs. Heterozygous (Tt)
The Punnett Square: graphical representation of all the possible combination of alleles
What is incomplete dominance?
Dominant and recessive traits produce an intermediate phenotype
Think the red and white flowers example!
