Language of Genetics
Mitosis
Meiosis
The Cell Cycle and Genetics
Mendelian Genetics
100
When a eukaryotic cell is not dividing, its genetic material can be found in the form of very long, thin fibers referred to as...
chromatin
100
The phase of mitosis during which the nuclear envelope fragments or breaks down, the nucleoli disappear, and distinct chromosomes become clear is called
Prophase
100
Fill in the blanks: While somatic cells (i.e. most of the cells in the body) have _____ chromosomes and are describes as being ________, gamete cells have _____ chromosomes and are described as being ______.
46 (23 pairs of homologous chromosomes), diploid, 23, haploid
100
What are the 3 phases of the cell cycle?
Interphase, mitosis, and cytokinises
100
What term is used to describe an allele that masks the physical trait expressed by another allele? What term is used to describe an allele that is masked or remains hidden in the presence of another allele?
Dominant. Recessive.
200
What are identical strands of DNA that remain connected after DNA replication called?
sister chromatids
200
Name the 4 phases of mitosis in correct order.
Prophase Metaphase Anaphase Telophase
200
What is crossing-over and when does it occur.
Crossing-over is when homologous chromosomes share genetic information. It occurs during Prophase I of meiosis.
200
What is the main difference of cytokineses in a plant and animal cell?
In animal cells a "cleavage furrow" is formed. In plant cells a "cell plate" is formed.
200
What is a genotype? What is a phenotype?
A genotype is the particular set of alleles carried by an individual and the phenotype is an individual's observable traits.
300
Two chromosomes in a nucleus that carry the genetic information for the same traits but specify different versions of some traits are called what?
Homologous Chromosomes
300
Describe what happens during Metaphase and Anaphase of mitosis.
During Metaphase sister chromatids line up on the midline of the cell. During Anaphase the sister chromatids are separated and move towards opposite spindle poles.
300
What is the "law of independent assortment" and when does it occur during meiosis?
The law of independent assortment says that maternal and paternal homologous chromosomes line up randomly on the mid-line of the cell, so that it is very rare for two daughter cells to have the same chromosomal makeup. The lining up of homologous chromosomes occurs during metaphase I of meiosis.
300
What are the 3 phases of Interphase and what occurs at each step?
G1- The cell grows and organelles are replicated. S- DNA is replicated G2- The cell grows and organelles are replicated
300
What are two words that describe an individual with a pair of dominant alleles? An individual with a pair of recessive alleles? An individual with one dominant and one recessive allele?
Homozygous dominant. Homozygous recessive. Heterozygous.
400
What are alleles?
Genes on homologous chromosomes that carry similar types of genetic information (i.e. alternate versions of the same gene).
400
What happens during Telophase? What is the end product? (In your answer include the number of cells, whether haploid or diploid, and whether the cells are identical or non-identical).
During Telophase the nuclear envelope reforms, the spindle apparatuses disappear, and the chromosomes unwind. At the end of Telophase the cell splits in two in a process called cytokinesis. The product is two identical diploid cells.
400
During which phase of meiosis do homologous chromosomes line up in the middle of the cell? During which phase of meiosis do sister chromatids line up in the middle of the cell?
Metaphase I. Metaphase II.
400
What is a non-disjunction chromosome error? What is an aneuploidy and what is one example.
The failure of sister chromatids or homologous chromosomes to separate during cell division. An aneuploidy is a chromosomal abnormality where an individual has too many or too few chromosomes. Down syndrome, or trisomy 21, is one example.
400
If a pea plant with purple flowers and a genotype of (Pp) is mated with a pea plant with white flowers with a genotype of (pp), what fraction of the next generation will have white flowers (pp)?
50% (this may require doing a Punnett square)
500
What term is used to describe when a cross between organisms with two different phenotypes produces offspring with a third phenotype that is a blending of the two alleles? What term is used to describe when a cross between organisms with two different phenotypes produces offspring that expresses both alleles equally?
Incomplete dominance. Co-dominance.
500
Describe 1 similarity between mitosis and meiosis and two differences.
Answers may vary, but here is one possibility: Similarities: Both are processes of cell division. Differences: In mitosis the product is two identical diploid cells and in meiosis the product is four non-identical haploid cells. Meiosis involves two cycles of cell division, whereas mitosis involves only one.
500
Name 4 processes that contribute to genetic diversity, and (if applicable) name at which stage of meiosis they occur.
- Crossing over: Homologous chromosomes share genetic information. Occurs in Prophase I. - Law of Independent Assortment: Homologous chromosomes line up at random at the midline of the cell so that daughter cells rarely have the same combination of genes. Occurs during Metaphase I. - Law of Segregation: Homologous chromosomes are separated into separate daughter cells. Occurs during Anaphase I. - Fertilization: Egg and sperm gamete cells meet and combine to form a new individual. This happens after meiosis.
500
Describe the following chromosomal errors that can happen during the process of cell division: Inversion Translocation Deletion
Inversion: When a fragment of DNA attaches in reverse order. Translocation: When a fragment of DNA attaches in the wrong place. Deletion: When a fragment of DNA is lost.
500
Human AB blood type is an example of what type of genetic expression?
Co-dominance
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