Check answers and help ?
1. What does the notation TT mean to geneticists?
a.) two dom. alleles < My answer
b.) heterozygous alleles
c.) at least one dom alleles
d.) one dom. and one recessive allele
2. An organism's genotype is
a.) its physical appearance
b.) its combo. of alleles < My answer
c.) the mutations it inherits
d.) the crossing over that occurs during meiosis
3. An organism's phenotype is
a.) its physical appearance
b.) its combo. of alleles < My answer
c.) the mutations it inherits
d.) the crossing over that occurs during meiosis
4. What occurs during meiosis but not during mitosis?
5. What is the probability of two tall pea plants, heterozygous for the tall alleles, producing a short pea plant?
8. Scientist believe cancer occurs when
1. The correct answer is c.) at least one dominant allele. To understand why this is the correct answer, you need to know the meaning of the notation TT in genetics. In genetics, letters are commonly used to represent alleles, which are alternative forms of a gene. In this case, T represents the dominant allele for a specific trait. The notation TT means that an organism has two copies of the dominant allele, indicating that it is homozygous for the dominant trait.
2. The correct answer is b.) its combination of alleles. Genotype refers to the genetic makeup of an organism, which is determined by the alleles it possesses for various genes. Alleles can come in different forms, such as dominant or recessive, and the combination of these alleles determines an organism's genotype.
3. The correct answer is a.) its physical appearance. Phenotype refers to the observable characteristics or traits of an organism. It is determined by the interaction between an organism's genotype (its genetic makeup) and the environment. While genotype influences phenotype, it is the physical appearance or manifestation of the genes (alleles) that can be observed.
4. During meiosis, a process that occurs during the formation of reproductive cells (gametes), genetic material is exchanged between homologous chromosomes through a process called crossing over. This genetic recombination results in increased genetic diversity. Mitosis, on the other hand, is a process of cell division that occurs in somatic cells, where genetic material is replicated and divided equally between two daughter cells. Therefore, crossing over during meiosis does not occur in mitosis.
5. To determine the probability of two tall pea plants, heterozygous for the tall alleles, producing a short pea plant, you need to understand Mendelian genetics and the principles of inheritance. In this case, the tall allele (T) is dominant, and the short allele (t) is recessive. Assuming both pea plants are heterozygous (Tt), there is a 25% chance (1 out of 4) that they will produce a short pea plant (tt), as the short allele can be inherited from both parents.
8. Scientists believe cancer occurs when there is an uncontrolled growth and division of cells due to genetic mutations. These mutations can be acquired (somatic mutations) or inherited (germline mutations). Somatic mutations accumulate in cells over time due to various factors like exposure to carcinogens, radiation, or errors in DNA replication. The mutations disrupt normal cell cycle control mechanisms, leading to uncontrolled cell proliferation and the formation of tumors.