Meiosis and Mandel Flashcards
What are Karotypes?
an image of all the chromosomes in a cell
What are the difference between the chromosomes of males and females?
Males have one X chromosome and one Y chromosome and females have two X chromosomes
What are chromosomes?
X-shaped strands of DNA that carry genes and regulatory information
What does the chromosome of an individual with down syndrome look like?
an individual with down syndrome has a repeated 21 chromosomes (3 chromosome 21’s)
What is meiosis?
a form of nuclear division that divides diploid cells into haploid cells (essential for sexual reproduction)
During meiosis what happens to chromosome numbers?
This process divides chromosome number in half (Haploid cells)
What is fertilization?
The fusion of an egg and a sperm cell
What is an allele?
any of the alternative form of a gene that occurs at a specific point
What is a genotype?
all of an organisms genes
What is a phenotype?
the physical characteristics/traits that make up an organism
What is sexual reproduction?
The process by which two gametes fuse and the offspring of the individuals are a genetic mixture of both of the parents
What is a trait?
Distinguishing features that are inherited (i.e. eye colour)
What is a cross in terms of genetics?
The mating of two organisms
What is meiosis 1?
A process that divides homologous chromosomes to create two haploid cells with duplicated chromosomes
What is meiosis ll?
A process that divides sister chromatids and results in undoubled chromosomes
What is the number of chromosomes a human has after meiosis?
46 chromosomes (23 pairs)
What is a haploid cell?
A cell that has only one copy of each chromosome (22 autosomes and 1 sex chromosomes)
What is a diploid cell?
A cell that has two copies of each chromosomes (one from mom and one from dad)
What is a sister chromatids?
single half strands of a chromosome that are connected at the centromere to form a whole chromosome
What is crossing over?
a process when germ cells divide where segments of DNA are exchanged between homologous chromosomes and create greater variation
Why do cell cross over?
Creates genetic variation through independent assortment
