Benchmark 2 Genetics Flashcards
identify the gametes
sperm and egg
How many chromosomes does each gamete contain
23
Is it possible for two sperm to fertilize one egg? What would be the result
Rare, cells will die.
Gametes develop from parent cells called what?
Germ cells
cells that have 2 from each chromosome (gametes)
diploid
produce a single a copy of chromosome (body cells)
haploid cells
What is meiosis
to reduce the number of chromosomes in each of the four new nuclei by half ( creating unique gene combinations)
What is the ultimate goal of meiosis?
crossing over genes
At what stage of meiosis does crossing over occur?
Prophase 1
What is the name of the site crossing over?
Chiasma
What does a “tetrad” refer to?
the homologous chromosomes that are pressed together in prophase 1
considered the father of genetics
Gregor Mandel
Why was his work different?
he applied basic math
three reasons that pea plants are a good choice for early genetics experiments?
- Easy grow
- They show contrasting traits
- Able to be self pollinated, and cross pollinated
What characteristics of pea plants are dominant?
Purple flower, yellow seed, round seed, green pod, smooth pod, mid stem flower, tall plant
alleles splitting up during meiosis
Law of Segregation
the alleles separate independently of each other
Law of Independent Assortment
one trait can cover up another trait
Law of Dominance
Was Mendel’s work respected during his lifetime?
No
What is the size of order a chromosome, gene, DNA molecule, nucleotide
Nucleotide, DNA molecule, gene, chromosome.
What % of genetic similarity do we have with chimpanzee?
95%
the trait that will express
dominant
the trait that can be represented
recessive
the actual gene contribution
genotype
the physical appearance of the trait
phenotype
has one of each type of gene
heterozygous
has tow of the same gene
homozygous
a cross for one trait
Monohybrid
a cross for two traits
dihybrid
How do master genes contribute to gene expression?
coordinate the activity of the genes
What 3 factors can determine how are genes are expressed?
weather, nutrition, stress
Sickle cell is both good and bad…Why?
Than you are immune from Malaria in the tropics. Heterozygous will be protected from sickle cell, and malaria. any other gene contribution you will die either from sickle cell or malaria
mutations in what kind of cells can be passed on to offspring and thus affect future generations
gametes
What does a punnett square predict
all the possible offspring of two parents
chromosomes become visible. the nuclear envelope breaks down. Crossing - over occurs.
Prophase 1
pairs of homologous chromosomes move to the equator of the cell.
Metaphase 1
homologous chromosomes move to the opposite poles of the cell.
Anaphase 1
Chromosomes gather at the poles of the cell. the cytoplasm divides.
telophase 1 and cytokanesis
a new spindle forms around the chromosomes
Prophase 2
Chromosomes line up at the equator
Metaphase 2
Centromeres divide. Chromatids move to opposite poles of the cell.
Anaphase 2
a nuclear envelope forms around each set of chromosomes. The cytoplasm divides
telophase 2 and cytokanesis
