creating variations
Which of the following does NOT promote variation within a population?
1. independent assortment
2. Mitosis
3. mutation
4. crossing over
2. Mitosis
All are true of crossover EXCEPT
1. It occurs between sister chromatids
2. causes variation
3. occurs during prophase I
4. It is a common event
5. It occurs between homologous chromosome pairs
1. It occurs between sister chromatids
If a cell has 24 chromosomes at the beginning of meiosis, how many chromosomes will the daughter cells have at the end of meiosis?
1. 48
2. It will vary every time meiosis occurs
3. 20
4. 12
5. 24
4. 12
All of the following are examples of ASEXUAL reproduction EXCEPT:
1. fertilization of an egg cell
2. budding
3. parthenogenesis
4. binary fission
5. fragmentation
1. fertilization of an egg cell
The potentially dangerous situation when either a pair of homologous chromosomes or sister chromatids fail to separate during meiosis is known as:
1. chiasmata
2. crossing over
3. nondisjunction
4. translocation
3. nondisjunction
Variation within a population occurs because of several different mechanisms. Which of the following choices promotes variation during prophase I due to exchange of material between homologous chromosomes?
1. mutation
2. random assortment
3. random fertilization
4. crossing over
5. nondisjunction
4. crossing over
All or the following are true of meiosis EXCEPT:
1. Crossover occurs during prophase I
2. synapsis occurs during prophase I
3. Sister chromatids are separated during Anaphase I
4. Homologous chromosomes are separated during anaphase I
5. Four genetically different gametes are produced.
3. Sister chromatids are separated during Anaphase I
Synapsis, tetrad formation, and crossing over occur during
1. Anaphase I
2. Anaphase II
3. Prophase I
4. Interphase
5. Prophase II
3. Prophase I
If the diploid number (2n) is 96, then the haploid number (n) is _____ after meiosis occurs.
1. 48
2. 192
3. 96
4. 0.5
5. 24
1. 48
TRUE OR FALSE?: Alternation of generations is commonly found in plants.
TRUE
The gain of an extra chromosome during meiosis results in a condition known as (choose all that apply, there are more than 1 answer):
1. euploidy
2. trisomy
3. monosomy
4. anueuploidy
2. trisomy, 4. anueuploidy
The locations on homologous chromosomes where genetic material is exchanged during crossing over are known as:
1. chiasmata
2. kinetochores
3. spindles
4. centromeres
1. chiasmata
Meiosis creates _____________ cells.
1. 2 genetically different haploid gametes.
2. 4 genetically different diploid gametes
3. 4 genetically different haploid gametes
4. 2 genetically identical diploid gametes
5. 4 genetically identical haploid gametes
3. 4 genetically different haploid gametes
Organisms that have MORE than two sets of homologous chromosomes are called:
1. euploid
2. haploid
3. polyploid
4. diploid
3. polyploid
Humans exhibit which type of life cycle:
1. Alternation of generations
2. haploid (1N) life cycle
3. diploid (2N) life cycle
4. binary fission
3. diploid (2N) life cycle
Examples of chromosomal structural rearrangement errors that can occur during meiosis include all of the following EXCEPT:
1. deletions
2. disjunctions
3. inversions
4. translocations
5. duplications
2. disjunctions
Normal diploid body cells that have both parents chromosomes are called somatic cells. The final haploid cells created in the gonads are called
1. chiasmic cells
2. synaptic clones
3. gametophytes
4. gametes
5. haploidians
4. gametes
Triploids are usually sterile because:
1. they don't occur in nature.
2. they cannot undergo mitosis.
3. 1/3 of the chromosomes cannot pair.
4. none of the chromosomes can pair up.
3. 1/3 of the chromosomes cannot pair.
What is a likely evolutionary advantage of sexual reproduction over asexual reproduction?
1. sexual reproduction results in greater variation in the offspring
2. sexual reproduction is more cost-effective with regards to energy usage
3. sexual reproduction involves fewer steps
4. less chance of using up the resources in a given
1. sexual reproduction results in greater variation in the offspring
Abnormalities in the number of X chromosomes tend to be milder than the same abnormalities in autosomes because of ________.
1. non-homologous recombination
2. X inactivation
3. synapsis
4. deletions
2. X inactivation
The number and appearance of chromosomes is known as the:
1. prokaryote
2. pictograph
3. zygote
4. karyotype
4. karyotype
Which event leads to a diploid cell being formed from 2 haploid cells, in a life cycle?
1. meiosis
2. alternation of generations
3. fertilization
4. mutation
3. fertilization