Bio Test 3 Flashcards
Budding
- Asexual reproduction process
- Organism develops from bud
- Genetically identical
Asexual Reproduction
- 1 single parent
- Genetically identical
- Mitosis
Sexual Reproduction
- 2 parents
- Genetically diverse
Chromosome
Condensed form of chromatin (histones & DNA) through supercoiling
Unreplicated Chromosome
Chromosome with just 1 DNA molecule (in the fom of a chromatid)
Replicated Chromosome
Chromosome with 2 DNA molecules (in the form of sister chromatids) held together by a centromere
Sister Chromatids
Two DNA molecules (chromatids) w/ same DNA (in a replicated chromosome)
Gene
Segment of DNA that codes for proteins or functional RNA molecules
Gene Locus
Location of a specific gene on a chromosome
Karyotype
Display of someone’s chromosomes (22 chomosome pairs + sex chromosomes)
Homologous Chromosomes
- Two chromosomes w/ the same genes (but different DNA)
- Usually one paternal and one maternal
- Those chromosomes are alleles
Alleles
Different versions of the same gene (~1 nucleotide difference)
Autosomes
Non-sex chromosomes; any of the chromosomes 1-22
Gametes
- Reproductive cells (sperm + ovum/egg)
- Haploid
- 1/2 regular # of chromosomes
- 23 chromosomes
Somatic Cell
- Diploid
- 46 chromosomes
Genotype
Genetic makeup of an individual (compilation of genes)
Phenotype
Physical and observable characteristics coded for by genes
Zygote
Fertilized egg
Meiosis
- Only for sexually-reproducing organisms
- Results in 4 haploid cells
- Consists of Meiosis 1 and 2
Prophase I
- Nuclear membrane disappears
- Chromosomes become visible
- Homologous chromosomes pair up and exchanging chomosomal segments (“crossing over”)
Recombinant Chromatids
- Chromatids that exchanged chromosomal segments with homologous chromatid
- Involved in “crossing over”
Nonrecombinant Chromatids
Chromatids that are not involved in “crossing over”
Metaphase I
Chromosomes line up in the center/middle of the cell
Spindle Fibers
Spindle-like structures that grab and align chromosomes
Centromere
- Structure involved in holding together chromatids in duplicated chromosomes
- Contains spindle fibers
Anaphase I
Homologous chromsomes segregate
Telophase I
Cell membrane is pinched (animals)
Cytokinesis
Cells completely separated
Interkinesis
Pause between stages
Cleavage Furrow
The pinch in the cell membrane during telophase/cytokinesis