Biology Chapter 13 Meiosis and Sexual Life Cycle
Terms
undefined, object
copy deck
- The restoration of the diploid chromosome number after halving in meiosis is due to
- fertilization
- What is a karyotype?
- a pictorial display of an individuals chromosomes
- What are autosomes?
- chromosomes other than sex chromosomes
- A synatptonemal complex would be found during
- prophase I of meiosis
- During the first meiotic division (meiosis I)
-
homologous chromosomes separate
the chromosome number becomes haploid
crossing over between nonsister chromatids occurs
paternal and maternal chromosomes assort randomly - A cell with a diploid number of 6 could produce gametes with how many different combinations of maternal and paternal chromosomes?
- 8
- The DNA content of a diploid cell is measured in the G1 phase. After meiosis I, the DNA content of one of the two cells produced would be
- equal to that of the G1 cell
- In most fungi and some protists
- the mulitcellular organism is haploid
- In the alternation of generations found in plants
- the gametophyte generation produces gametes by meiosis
- What is likely to be a source of genetic variation in sexually reproducing organisms?
-
crossing over
independent assortment of chromosomes
random fertilization of gametes
mutation - What is least likely to be a source of genetic variation in sexually reproducing organisms?
- replication of DNA during S phase before meiosis I
- Meiosis II is similar to mitosis because
- sister chromatids separate
- Pairs of homologous chromosomes
- have genes for the same traits at the same loci
- Asexual reproduction of a diploid organism would
- produce identical offsrping
- In sexually reproducing species with a diploid number of 8, how many different combinations of paternal and maternal chromosomes would be possible in offspring?
- 256
- How many chromatids are present in metaphase II in a cell undergoing meiosis from an organism in which 2n=24?
- 24
- What is considered to be a haploid cell?
-
a daughter cell after meiosis II
gamete
daughter cell after mitosis in gametophyte generation of a plant
cell in prophase II - What is not considered to be a haploid cell?
- a cell in prophase I
- Homologous Chromosomes
-
behave independently in mitosis
travel together to the metaphase plate in prometaphase of meiosis I
Each parent contributes one set of homologous chromosomes to an offspring
Crossing over between nonsister chromosomes is indicated by the presence of chiasmata - What is not true of Homologous Chromosomes?
- They synapse during S phase of meiosis
- What describes why or how recombinant chromosomes add to genetic variability?
-
they randomly orient during metaphase II and the nonequivalent sister chromatids separate in anaphase II
Genetic material from two parents is combined on the same chromosome - A cell in G2 phase before meiosis compared with one of the four cells produced by that meiotic division has
- four times as much DNA and twice as many chromosomes.