Final Exam Study Guide Flashcards
Why it is necessary for mitosis to result in identical daughter cells
identical - same cell & function
Events that occur in each phase of the cell cycle
- cell growth and cell division that produces two new daughter cells
- Interphase = cell grows & DNA replicates
(G1 - cell active, little change)
(S - DNA replicated, sister chromatids)
(G2 - prepares to divide)
- Mitotic = cell divides into two new identical daughter cells
Events that occur in each stage of mitosis
- 4 stages
- Prophase = chromsomes condense, crossing over occurs
- Metaphase = chromosomes align along metaphase plate
- Anaphase = sister chromatids split apart, opposite ends of cell
- Telophase = nuclear envelope forms 2
Cytokinesis in an animal cell vs in a plant cell
- cytoplasm divides into two new daughter cells
A - cleavage furrow
P - cell plate
Cancer
- Cells losing control of their cell cycle, repeatedly divides
-Neoplasm = clump of same mutated cells
-telomerase enzyme = divides indefinitely
- Tumor = mass of cells
- Oncogene = mutation that causes tumor development
- Proto-oncogene = normal gene converts to an oncogene
Explain what causes a cell to grow uncontrollably
- improper replication of DNA during the S phase
- gene mutation
Sex chromosomes
- XY chromosomes
- determine sex
Autosomes
Non-sex chromosome
- first 22 chromosomes
- homozygous
Somatic Cells
- Human body cells
- contains 46 chromosomes (diploid)
Gametes
Haploid sex cell - egg / sperm
Diploid vs Haploid
- Diploid 46 chromosomes, associated with mitosis
- Haploid 23 chromosomes, associated with meiosis
Relationship between meiosis and sexual reproduction
Meiosis produce sex cells that join to form zygote during sexual reproduction
Events that occur in each stage of meiosis
Meiosis I:
- separation of homologous pairs
PI - recombinant chromosomes
MI - align on the metaphase plate
AI - homologous chromosomes are separated
TI - nuclear envelope forms
Meiosis II:
- separation of sister chromatids
PII - nuclear envelope breaks down
MII - align metaphase plate
AII - separated sister chromatids move toward opposite poles of the cell
TII - Individual chromatids, nuclear envelope forms
Similarities and differences between mitosis and meiosis
Similarity - Both are preceded by DNA replicated in S phase
Difference - Meiosis = 4 haploid daughter cells / Mitosis = 2 identical daughter cells
Self-fertilization vs cross fertilization
Self = fusion of sex cells by the same individual (flowers)
Cross = two different true-breeding traits together
Genes - heritable traits
Alleles - variants of a gene - determine trait
True-breeding
offspring identical to the parent
Heterozygous vs homozygous
Homozygous = two identical alleles
Heterozygous = Different alleles, One dominant, one recessive
Phenotypic ratio versus Genotypic ratio
Phenotype - ratios of visible characteristics / 3 green : 1 yellow
Genotypic - ratio of different genotype / 1 (YY) :2 (Yy) :1 (yy)
P generation - first generation in a cross
F1 generation - offspring of the parental generation
F2 generation - offspring from F1 self fertilizing or fertilized
Pedigrees
chart that shows trait or health condition through generations
Mendel’s law of segregation
Genes segregate equally into gametes
one allele for each gene
law of independent assortment
Genes do not influence each other
Why linked genes do not always follow Mendel’s law of independent assortment
alleles tend to transmit together not independently
Explain how genetic variation in a species occurs, including mutations and inheritance patterns
- sexual reproduction = new combinations of genes
- Mutations = change dna sequence