Meiosis and Life Cycles Flashcards
What do we mean by heredity or inheritance?
Traits being passed down from one offspring to another
What is variation? Why is there variation among siblings?
Genetic differences; crossing over and various combinations of genes (about 60 trillion per couple)
What is the study of genetics?
The study of both heredity and the variation that exists
What is a gene?
A discrete unit of hereditary information
consisting of a specific nucleotide sequence in
DNA (or RNA, in some viruses).
What are gametes and what do they have to do with heredity?
Sex cells- (haploid) they have half the chromosomes from mom and half from dad and are passed on to offspring
What are somatic cells?
Non sex cells. Diploid
What is a chromosomal locus? What does that have to do with genes?
A specific
place along the length of a chromosome where
a given gene is located. Behavior of chromosomes during meiosis accounts for inheritance patterns.
What is a clone?
Genetically identical
Made from Asexual reproduction- from somatic cells
When a species is asexual reproduction there are no variations thus they are all susceptible to same dangers.
What are homologous chromosomes?
The same type of chromosome
One from mom and one from dad
We have 46 chromosomes-23 pairs
What are sister chromatids?
Identical chromosomes held together by a centromere
What is a Karyotype?
A display of the chromosome
pairs of a cell arranged by size and
shape.
What do we mean by autosomes and sex chromosomes?
Chromosomes 1-22 are autosomes- they are somatic and number 23 are the sex chromosomes
What is meant by diploid and haploid?
Diploid have all 46- haploid 23 - numbers of genes in a specific cell
What is synapsis?
The pairing and physical
connection of duplicated homologous chromosomes
during prophase I of meiosis.
What is the synaptonemal complex doing?
A zipper-like structure composed of
proteins, which connects two homologous
chromosomes tightly along their lengths
