Ch. 10 Meiosis + Sexual Life Cycles Flashcards
The synaptonemal complex __________.
physically connects homologous chromosomes during prophase I
Spores and gametes differ in that __________.
gametes must fuse to form a zygote and continue development, but each spore can develop into an independent multicellular organisms on its own
Which of the following occurs during anaphase II?
Sister chromatids separate and migrate toward opposite poles.
In a male mammal, every germ cell that undergoes meiosis in the production of gametes gives rise to __________ sperm.
four
Sister chromatids __________.
are identical copies of each other formed during DNA synthesis
Crossing over occurs during __________.
prophase I
Which of the following is included in alternation of generations?
All of the listed responses are correct.
How many different combinations of maternal and paternal chromosomes can be packaged in gametes made by an organism with a diploid number of 8 (2n = 8)?
16
Homologous chromosomes move toward opposite poles of a dividing cell during __________.
meiosis I
A karyotype is a __________.
photograph of all of an individual’s chromosomes
Which of the following contributes to genetic variation in sexually reproducing species?
Independent assortment, crossing over, and random fertilization
Human somatic cells contain __________ set(s) of chromosomes and are therefore termed __________.
two; diploid
Fertilization produces a __________.
diploid zygote
How many genes are present in the human genome?
Tens of thousands
How many pairs of autosomes do humans have?
22
Which of the following statements best describes the advantage that sexual reproduction likely provides over asexual reproduction?
Although energetically more costly than asexual reproduction, sexual reproduction leads to different combinations of alleles that could provide adaptability in a changing environment.
In sexually reproducing species, the chromosome number remains stable over time because __________ and __________ always alternate.
meiosis; fertilization
What is a locus?
The precise location of a gene on a chromosome
Which event occurs only during prophase I of the first meiotic division?
Synapsis of homologous chromosomes occurs.
In a diploid set of chromosomes, one member of each pair of homologous chromosomes is derived from the father (paternal) and the other comes from the mother (maternal). If 2n = 6, what is the probability of obtaining a gamete in which all the chromosomes are paternal ones?
⅛
A human cell containing 22 autosomes and a Y chromosome is a __________.
sperm
Synapsis occurs during __________.
prophase I
