Cancer and Meiosis Flashcards
(19 cards)
What percentage of Americans will develop cancer?
Forty percent
This statistic highlights the prevalence of cancer in the U.S. population.
What are the two types of defects related to cell division in cancerous cells?
- Activate proteins for cell growth when they should not be active
- Prevent tumor suppressor genes from shutting down the cell cycle
What is the role of the p53 tumor suppressor?
It binds to enhancers of genes to arrest the cell cycle and repair DNA damage or trigger apoptosis if damage is irreparable.
True or False: Mutant forms of the p53 gene are found in over half of all human cancers.
True
What are the characteristics of abnormal cell growth in cancer?
- Excessive cell division
- Resistance to cell death (apoptosis)
- Evasion of the immune system
What is the lifetime risk of dying of cancer for a person in the U.S.?
1 in 5
This statistic indicates the severity of cancer as a health issue.
What are common emotional challenges faced by persons with cancer?
- Body image and self-esteem issues
- Depression
- Fear of cancer recurrence
- Loneliness
- Strain on relationships
What is the definition of meiosis?
Nuclear division that leads to halving of chromosome number
What are reproductive cells called in the context of meiosis?
Gametes
What is the result of fertilization?
A diploid cell called a zygote
What is the concept of ploidy in organisms?
- Diploid: Two homologs of each chromosome
- Haploid: One of each type of chromosome
- Polyploid: More than two homologs
What occurs during Meiosis I?
The two homologs of each chromosome pair separate into two daughter cells.
How many haploid daughter cells are produced at the end of meiosis?
Four haploid cells
What is crossing over in meiosis?
The exchange of genetic material between homologous non-sister chromatids at chiasmata.
What is the key difference between mitosis and meiosis?
Homologs pair in meiosis but not in mitosis.
What is nondisjunction?
A meiotic error where both homologs or sister chromatids move to the same daughter cell.
What is Down syndrome caused by?
An extra copy of chromosome 21, also known as trisomy 21.
What are the possible outcomes of fertilization involving an n + 1 or n - 1 gamete?
- n + 1 gamete leads to trisomy zygote (2n + 1)
- n - 1 gamete leads to monosomy zygote (2n - 1)
What are cells with too many or too few chromosomes called?
Aneuploid
