1.
Which of the following is a phase of mitosis?
Correct Answer
C. PropHase
Explanation
Prophase is a phase of mitosis where the chromosomes condense and become visible under a microscope. During prophase, the nuclear membrane breaks down, and the spindle fibers start to form. This phase is crucial for the proper separation of genetic material during cell division. Cytokinesis is the final stage of the cell cycle where the cytoplasm divides, while interphase is the period between cell divisions where the cell grows and prepares for division. S phase is a subphase of interphase where DNA replication occurs.
2.
If the parent cell starts with 24 Chromosome and undergoes mitosis, then how many will the daughter cells have?
Correct Answer
D. 24
Explanation
During mitosis, the parent cell divides into two identical daughter cells. Each daughter cell will contain the same number of chromosomes as the parent cell. Therefore, if the parent cell starts with 24 chromosomes, the daughter cells will also have 24 chromosomes.
3.
The principle of dominance states that:
Correct Answer
C. Some alleles are dominant and others recessive.
Explanation
The principle of dominance states that some alleles are dominant and others are recessive. This means that when an individual has two different alleles for a particular trait, one allele may be expressed over the other, resulting in the dominant phenotype. The recessive allele is only expressed when an individual has two copies of it. This principle helps explain the inheritance patterns observed in genetics, where dominant alleles mask the expression of recessive alleles.
4.
Which of the following accurately describes a phase of mitosis?
Correct Answer
B. PropHase: The nuclear envelope breaks down, and the chromosomes condense and become visible
Explanation
Prophase is a phase of mitosis where the nuclear envelope breaks down, and the chromosomes condense and become visible under a microscope. During this stage, the mitotic spindle also begins to form, which will later help in separating the chromosomes. This stage is crucial for the proper alignment and segregation of chromosomes during cell division.
5.
What is the last phase of mitosis?
Correct Answer
A. TelopHase
Explanation
The last phase of mitosis is telophase. During telophase, the duplicated chromosomes reach the opposite poles of the cell and begin to decondense. Nuclear envelopes start to form around each set of chromosomes, creating two separate nuclei. Additionally, the spindle fibers disassemble, and the cell undergoes cytokinesis, resulting in the division of the cytoplasm into two daughter cells.
6.
Organisms that have two identical alleles for a trait are called what?
Correct Answer
B. Homozygous
Explanation
Organisms that have two identical alleles for a trait are called homozygous. This means that both alleles for a specific trait are the same, either both dominant or both recessive. Homozygous individuals will always express the trait associated with those alleles. In contrast, heterozygous individuals have two different alleles for a trait, while hybrids are the result of crossing two different species or varieties. Dominant refers to an allele that is expressed over a recessive allele in a heterozygous individual.
7.
Put the following stages in the cell cycle in order.
Correct Answer
D. 2, 3, 1, 5, 4
Explanation
The correct order of the stages in the cell cycle, based on the provided images, follows the sequence of mitosis phases. Starting with Image 2, which shows Prophase where chromosomes condense and become visible, followed by Image 3 depicting Metaphase with chromosomes aligned in the center. Image 1 represents Anaphase, where chromosomes are pulled apart. Subsequently, Image 5 illustrates Cytokinesis, where the cell splits into two daughter cells. Finally, Image 4 shows Telophase, where nuclear membranes form around each set of chromosomes. Thus, the correct order is D: 2, 3, 1, 5, 4.
8.
In Meiosis, if the parent cells have 40 chromosomes, then how many will the daughter cells have?
Correct Answer
C. 20
Explanation
During meiosis, the parent cells undergo two rounds of cell division, resulting in the formation of four daughter cells. Each daughter cell will have half the number of chromosomes as the parent cell. Therefore, if the parent cells have 40 chromosomes, the daughter cells will have 20 chromosomes each.
9.
Which is an example of a heterozygous allele?
Correct Answer
A. Tt
Explanation
The example of a heterozygous allele is Tt. In genetics, heterozygous refers to having two different alleles for a particular gene. In this case, the uppercase T represents one allele and the lowercase t represents a different allele. This combination of alleles in Tt demonstrates heterozygosity. The other options, tt and TT, represent homozygous alleles where both alleles are either lowercase or uppercase, respectively. Therefore, the correct answer is Tt.
10.
Does meiosis produce which of the following?
Correct Answer
C. Sex cells
Explanation
Meiosis is a type of cell division that specifically occurs in the reproductive organs of organisms. It is responsible for the production of sex cells, also known as gametes. These gametes, such as sperm and eggs, are involved in sexual reproduction and carry half the number of chromosomes compared to the parent cell. Therefore, the correct answer is sex cells.