Bio: Genetics and Hereditary

Haploid cells have ____ copies of each chromosome

1 copy

Diploid cells have ____ copies of each chromosome

2

If two parents are heterozygous, what are the chances their child will be homozygous recessive? A. 25% B. 50% C. 75% D. 100%

A

Which description supports the claim that mutations in gametes could cause an increase in genetic diversity in a population? A. A deletion during meiosis results in a new version of an allele B. A drug creates a mutation on a liver cell, the mutated cell multiplies C. UV rays create thymine dimers that negatively affect a skin cell's function D. A brain cell has a missense mutation that allows it to function more effectively

A

Mendel's Law of Segregation

Alleles segregate from one another during the formation of gametes.

A scientist examines a human cell with 23 chromosomes and hypothesizes that this cell is the product of meiosis. Which of these would provide further evidence that the cell is the product of meiosis? A. The chromosomes in the cell consist of only autosomes B. The chromosomes in the cell lack a homologous pair in the same cell C. The chromosomes in the cell are contained within a nuclear membrane D. The chromosomes in the cell were not replicated before the cell divided

B

Which of these best explains the role of recombination in increasing genetic diversity? A. Recombination allows fertilization to occur after meiosis B. Recombination causes alleles of genes to be switched between homologous chromosomes C. Recombination causes the number of chromosomes in sex cells to change D. Recombination causes the order of the bases of DNA sequences to become reversed

B

After being exposed to radioactivity, a strand of DNA with the sequence ATTATCTGC has been changed to ATTCGATCTGC. As a result of being exposed to radioactivity, a(n) ________ mutation has occurred. This caused a change to the ________ sequence in the organisms genome and can potentially lead to an alteration of the ________ sequence in an expressed protein. A. Deletion B. Insertion C. Amino acid D. Nuclei acid

B., D., C.

Which is not a factor that could increase the rate of mutation in a cell? A. Exposure to a chemical carcinogen B. Infection with a virus, such as HPV C. Exposure of the cell to UV radiation D. Environmental pressure to adapt for survival

D

Which type of mutation would a karyotype best help to discover? A. Point mutation B. Frameshift mutation C. Gene duplication mutation D. Nondisjunction mutation

D

Scientists find a mouse has two non-mutated copies of a gene as well as a mutated copy

Gene duplication

Explain the role of meiosis in genetic variatiion

Meiosis creates the chromatids for crossover

A plant is tetraploid

Nondisjunction

An individual has three copies of chromosome 21

Nondisjunction

A person has a section of chromosome 15 on chromosome 2

Translocation