Meiosis & Genetics Flashcards
What does homologous mean?
Similar, but not identical
What is a haploid cell?
Cell with 23 chromosomes
What is a diploid cell?
2n Cells
What is fertilization?
haploid gamete joins with another haploid gamete
What is a diploid cell?
cell with 2n chromosomes
What is meiosis?
cell division that reduces the number of chromosomes by half through the separation of homologous chromosomes
What is a gene?
DNA on the chromosomes is arranged in sections that
control the production of protein
What happens during prophase I?
replicated chromosomes, consisting of two sister chromatids, condense
What is crossing over?
a section of one chromosome changes place with a section of its homologous chromosome
What happens during metaphase I?
the pairs of homologous chromosomes line up in the center of the cell
What happens during anaphase I?
each homologous chromosome is guided by the spindle fibers toward opposite poles of the cell.
What is the final stage of meiosis?
Telophase I
What happens during telophase I?
the homologous chromosomes reach opposite poles of the cell.
What is prophase II?
the spindle apparatus forms, and the
chromosomes condense
What is metaphase II?
a haploid number of chromosomes lines up near the center of the cell by the spindle fibers.
What is anaphase II?
the sister chromatids are pulled apart at the centromere by the spindle fibers, and the sister chromatids are pulled to the opposite poles of the cell
What is a gamete?
A sex cell (in humans: sperm for males, and eggs for females)
What are homologous chromosomes?
Set of chromosomes (one from each parent), that are very similar to one another and have the same size/shape
Dogs have 39 haploid cells, how many chromosomes will be in the diploid cell?
78
Where is the only place that crossing over occurs?
Prophase I
Do you think that interphase is apart of meiosis?
Yes
What is the difference in meiosis and mitosis?
Meiosis splits it’s diploid cells to start, while mitosis just duplicates them from the start
When do gametes get created?
After meiosis II
Which one can keep going infinitely, meiosis or mitosis?
Mitosis
What type off cell is meiosis?
A germ cell
What type of cell is mitosis?
Somatic
The somatic cells of a cat contain 38 chromosomes.
If a cat cell undergoes meiosis, how many chromosomes will be in the resulting cell?
19
What occurs during meiosis II?
The separation of sister chromatids
What is a likely result of crossing over during meiosis I?
Production of recombinant gametes
What is the overall purpose of meiosis?
To create gametes
Compare the differences of meiosis and mitosis.
Meiosis - Splits the diploid cells into haploid
Mitosis - Just duplicates the diploid cells
Compare the similarities of meiosis and mitosis.
Meiosis - Starts with a diploid cells
After the first stage they duplicate
Mitosis - Starts with a diploid cells
Duplicates
When does prophase I occur?
It is the first stage
What is genetic variation?
It is when something changes in a gene
Give some examples of genetic variation.
Some examples are eye color, hair color, height, etc…
What is an allele?
Different form of a gene passed from generation to generation
What does dominant mean?
The version of the trait that appears in the F1 generation
What does recessive mean?
The version that is hidden in the F1 generation
What is homozygous?
If both alleles for a trait are the same
What is genotype?
An organism’s allele pairs
What is a phenotype?
The way an organism looks or behaves
What is Mendel’s Law of Segregation?
he two alleles for each trait separate from each other during meiosis and then unite during fertilization.
What are hybrids?
When parents with different forms of a trait are crossed, the offspring are heterozygous organisms
What is heterozygous?
The alleles for a trait are different
What does the law of independent assortment state?
Alleles distribute randomly when gametes are made
What does a punnet square do?
Help you predict the genotype and phenotype of the offspring
How are two or more traits inherited?
Mendel found that the traits were inherited independently. Members of the F2 generation had the phenotypic ratio of 9:3:3:1—9 yellow round seeds, 3 green round, 3 yellow wrinkled, and 1 green wrinkled.
Does genetics run on probability?
Yes
How does probability work on genetics?
A cross might not give a perfect 3:1 or 9:3:3:1 ratio. The larger the number of offspring, the more closely the results will match the ratio predicted by the Punnett square
How is a Punnett square used for two traits?
A Punnett square for a dihybrid cross is larger. It has 16 boxes to represent 16 allele combinations.
