UNIT 11 - HUMAN GENETICS Flashcards
Hereditary
Transmission of traits from one generation to the next
Genetics
Scientific study of heredity and hereditary variation
Gene (6)
- Unit of hereditary that controls particular character
- Sequence of DNA
- Specific location on a chromosome
- Determines particular character
- Controls cellular structure/activities
- Determines chemical structure of structural proteins of cell & enzymes
Allele
Specific form of gene which controls trait (eg. Specific allele for a hair color gene determines that an individual will have trait brown hair)
Character
Observable feature such as hair color and eye color
Trait
Variant of a character such as red hair or brown hair
Phenotype
An organism’s physical appearance
Genotype
An organism’s genetic makeup
Chromatin
Complex of DNA and protein that form chromosomes
Chromatid
Duplicated strands of DNA joined at the centromere during cell division
Chromosome
Large condensed and organized structures formed by tightly coiled chromatids
Diploid cell
2 sets of chromosomes found in all body cells except gametes
Haploid cell
1 set of chromosomes found only in gametes (sperm and egg)
Somatic cell
Cells in the body other than sperm and egg cells and contain 46 chromosomes (23 pairs) where each pair is from maternal and paternal sources
Autosomes
Any non-sex chromosome; 22 pairs
Sex chromosomes
1 pair of sex chromosomes
Female sex chromosome
XX
Male sex chromosomes
XY
Homologous
Means same information
Mitosis
Process by which one cell gives rise to 2 daughter cells
Why must cells divide by mitosis (2)
- Growth: From fertilized egg to multi celled organism
- Repair & renewal: Replace cells that die from normal wear and tear or injury
Cell cycle (5)
- Interphase (non-dividing): Cell growth, DNA replication, organelle replication
- Mitotic phases (prophase, prometaphase, metaphase, anaphase, telophase): Duplicated chromosomes separate
- Cytokinesis: Division of cytoplasm
- Two daughter cells produced
- Identical to parent cell
Interphase:
Cell prepares for division