Lab 4 Flashcards
What is the ploidy of a cell?
What does diploid mean?
What does haploid mean?
Ploidy refers to the number of sets of chromosomes found in a cell
Diploid refers to organisms having two identical sets of chromosomes on their cell
Haploid refers to a cell with only one of each type of chromosome in the nucleus
What are homologous chromosomes?
How many do humans have?
Two identical sets of chromosomes of the same size shape and carrying the same genes
Humans have 46 chromosomes but 23 homologous chromosomes
Can be two single chromosomes together or two replicated chromosomes together
What are loci?
The location of where the genes are
What is he genotype?
The ordered list of alleles a cell or organisms carries
Ex: Aa, AA, aa, AaBb
Do homologous chromosomes always have the same alleles?
One chromosome may have either the same or a different allele for a given gene than its homologous partner
Same gene tho
How do you draw the stages of meiosis in terms of chromosomes?
Prophase- draw four circles together and then make them all chromosomes with the SAME GENE LINE ACROSS EACH
Metaphase- live them up vertically and draw spindles attached to centromeres, make sure to draw one spindle across the whole cell
Prophase II- draw two different cells with their pulled apart chromosomes
Metaphase II- like the chromosomes up HORIZONTALLY, make sure to draw one spindle across the cell
What is the male and female reproductive structures in a generalized flower?
Male- antheridium (U shape) releases sperm
Female- archegonium (sour ring sucker shaped with egg in the middle)
How does meiosis occur in plants?
Occurs in diploid cells called sporocytes within the reproductive organs called sporangia to form haploid spores
What is an alteration of generations?
The complex life cycles of pants where they have distinct multicellular haploid and diploid stages
What is a gametophyte? The sporophyte?
Gameto- The haploid generation of plants that produces gametes
Sporo- The diploid generation that produces spores
What is a rhizome?
A horizontal underground stem that the large leaves grow out which bears many roots
What are Sori?
Brown spots on ferns that develop on the underside of mature leaves
What two events occur in prophase I of meiosis that do not occur in prophase of mitosis?
In prophase meiosis I- homologous chromosomes form a tetrad
Genetic exchange occurs (crossing over)
How would you draw a prophase mitosis cell with genotype AaBb? What about meiosis prophase I?
You’d draw a deteriorating nuclear membrane and inside you’d put:
- a set of replicated chromosomes labeled AA with similar gene
- same thing but labeled BB
- Same thing but labeled aa
- same thing but labeled bb
For meiosis I same thing but pair the AA and aa up and the BB and bb up
What is the plant used in the petri-dish?
Brassica rapa
Fast plant
