Unit 5 Flashcards
AP Bio Test
What does PMAT stand for in meiosis?
Prophase, Metaphase, Anaphase, Telophase
What is the main purpose of meiosis?
To halve the chromosome number and generate genetic diversity
What happens during Prophase 1 of meiosis?
Homologous chromosomes cross over and exchange genetic information
What occurs during Metaphase 1?
Homologous pairs line up across the middle and attach to spindle fibers
What is the significance of Anaphase 1?
Homologous chromosomes are randomly assorted and separated, increasing genetic variation
What occurs in Telophase 1?
Chromosomes are condensed into half the chromosome number
Why is there no chromosome replication during interkinesis?
To avoid doubling the chromosome number after halving it in meiosis 1
How many rounds of division occur in meiosis?
Two rounds of division
What happens during Anaphase 2?
Sister chromatids split and are pulled to opposite ends
What is produced at the end of Telophase 2?
4 genetically different haploid cells
What is nondisjunction?
A meiotic error where chromosomes stay together or are short, affecting offspring
Give an example of a condition caused by nondisjunction.
Trisomy 21 (Down syndrome)
What is gametogenesis?
The process of forming gametes
What are the end products of sperm formation?
4 haploid sperm cells
What are the end products of egg cell formation?
1 egg cell and 3 polar bodies
True or False: Males have a limited number of sperm.
False
What can affect phenotypes besides genetics?
Environmental conditions such as temperature, soil pH, UV light, and colored light
What is phenotypic plasticity?
The ability of organisms to produce distinct phenotypes in response to environmental variation
How do you calculate the probability of desired offspring genotype?
Stack parents’ genotypes, check how many outcomes yield desired genotype, make a fraction and multiply
What is the number of chromosomes before meiosis?
46 chromosomes
What is the haploid number of chromosomes after the second round of meiosis?
23 chromosomes
Define X-linked dominant inheritance.
A dad can pass the trait to daughters but not to sons
Define X-linked recessive inheritance.
Affected males have carrier daughters
Where are mitochondrial genes found?
In mitochondria, not in the nucleus
