Genetics Answers

Probability rules can be used to solve genetics problems. An organism that has the genotype AaBbCC is crossed with an organism that has the genotype AaBbCc. Assume all genes are on separate sets of chromosomes (that is, they are not linked).
a) What is the probability that any of the offspring will have the genotype AABBCC?
Hint: To get the answer, first determine the probability of each allele in the gametes (i.e. egg and sperm). Next, determine the individual probabilities of getting AA offspring from the monohybrid cross. Then do the same to determine the probabilities of getting BB offspring and CC offspring. Finally, multiply these probabilities together.
b) What is the probability that any of the offspring will have the genotype AabbCc?

How are genotypic value, breeding value and gene combination value related?

Meiosis is divided into nine stages, each playing a vital role in the cellular division responsible for making gametes. Which of the following occurs in the meiosis stage known as telophase

Malignant tumors are sometimes treated with drugs that halt mitosis, and thus stop the production of new cancer cells. Two such drugs, vincristine sulfate and vinblastine sulfate, interfere with the formation of spindle fibers. How could this action halt mitosis? Antibiotics such as mitomycin C and inorganic compounds such as cis-platinum also can be used to stop the growth of tumors. These drugs interfere with DNA synthesis in treated cells. How could this action halt mitosis?

In a human, polydactyly is autosome dominant disease. The blood groups of system ABO are determined by three allelic genes: i0, IA, IB. The blood groups of a human being are i0i0 - I(0); IAIA or IAi0 - II(A); IBIB or IBi0 - III(B); IAIB - IV(AB). In a family, a mother had I blood group and polydactyly, the father had IV blood group and normal structure of hand. There was born a child with first blood group and normal structure of hand. Determine the parental genotypes and the probability of a child with III blood group and polydactyly.

The human blood groups of ABO system are determined by three allelic genes: IA, IB, i0 . The combination of alleles i0 i0 determine the I(O) blood group, IA IA or IA i0 - II (A); IB IB or IB i0 - III (B); IA IB - IV (AB). In a family, in which mother has II blood group (heterozygote), her husband - I blood group. Determine the possible blood groups of their children.

Sickle cell anemia (S-anemia) and thalassemia are inherited as the incomplete autosome dominant characters. The genes of these diseases are non-linked. The heterozygous for S-anemia and thalassemia individuals do not have clinical symptoms. The carriers of S-anemia or thalassemia do not affect malaria. The diheterozygotes have crescent anemia. The homozygous for S-anemia and thalassemia individuals die in childhood. Determine the probability of the birth of healthy children in the family, in which one parent is heterozygous for both characters, and another is homozygous recessive.

Sickle cell anemia (S-anemia) is inherited as autosome incomplete dominant character. Homozygotes for dominant character die before puberty, the heterozygotes have subclinic anemia. The plasmodium can not use the S-hemoglobin and human with S-anemia has no malaria. What is the probability of the birth of children not stable to malaria, in a family, in which both parents are stable to malaria.

Carry out a genetic cross of your choice and work out the ratio of F1 and F2 offspring

Patrick and his partner Patricia recently had Lil’ Patty and Patricia is worried that the hospital made a mistake and mixed her baby with some other starfishes’. Lil’ Patty has a short head! Patrick is homozygous for his tall head and Patricia is heterozygous for her tall head. Create a Punnett square using T for the dominant gene and t for the recessive one.