1.
All of the following are the end products of glycolysis except
Correct Answer
D. NAD+
Explanation
Glycolysis is the metabolic pathway that converts glucose into pyruvate. During this process, glucose is broken down into two molecules of pyruvate, generating a small amount of ATP and NADH. NAD+ is the oxidized form of NADH and is required for the continuation of glycolysis. Therefore, NAD+ is not an end product of glycolysis, but rather a coenzyme that is continuously regenerated in order to sustain the process.
2.
A single glucose molecule can drive the Krebs cycle:
Correct Answer
B. Two turns
Explanation
A single glucose molecule can drive the Krebs cycle for two turns. The Krebs cycle, also known as the citric acid cycle, is a series of chemical reactions that occur in the mitochondria of cells. Glucose is broken down during this cycle to produce energy in the form of ATP. Each turn of the Krebs cycle produces three molecules of NADH, one molecule of FADH2, and one molecule of ATP. Since glucose is first converted into two molecules of pyruvate, each pyruvate molecule enters the Krebs cycle and completes one turn. Therefore, a single glucose molecule can drive the Krebs cycle for two turns.
3.
In a cell exposed to DNP, how many ATP molecules would be generated per molecule of glucose?
Correct Answer
B. 4
Explanation
In a cell exposed to DNP, the process of oxidative phosphorylation is uncoupled, which means that ATP synthesis is disrupted. However, some ATP can still be generated through substrate-level phosphorylation during glycolysis. In glycolysis, one molecule of glucose is converted into two molecules of pyruvate, and during this process, a net of two molecules of ATP are produced. Therefore, in a cell exposed to DNP, four molecules of ATP would be generated per molecule of glucose through glycolysis.
4.
Eukaryotic chromosomes are composed of a complex of 60% protein and 40% DNA. The name of this chemical complex is:
Correct Answer
B. Chromatin
Explanation
Chromatin is the correct answer because it accurately describes the chemical complex found in eukaryotic chromosomes. Chromatin is composed of approximately 60% protein and 40% DNA. It is responsible for packaging and organizing the DNA within the nucleus of a cell. Histone complex, histamine complex, chromatid, and centromere are not the correct answers as they do not accurately represent the composition or function of eukaryotic chromosomes.
5.
If a eukaryotic cell has a single set of chromosomes, it is called:
Correct Answer
A. Haploid
Explanation
A eukaryotic cell with a single set of chromosomes is called haploid. In haploid cells, there is only one copy of each chromosome, which is represented by the letter "n". This is in contrast to diploid cells, which have two sets of chromosomes (2n), and polyploid cells, which have multiple sets of chromosomes (3n, 4n, etc.). Haploid cells are typically found in reproductive cells, such as sperm and egg cells, and are involved in sexual reproduction.
6.
The physical map of the array of chromosomes is called a:
Correct Answer
C. Karyotype
Explanation
A karyotype refers to the physical map of an array of chromosomes. It provides a visual representation of the chromosomes in an organism's cell, arranged in pairs according to size, shape, and other characteristics. By examining a karyotype, scientists can identify and analyze any abnormalities or variations in an individual's chromosomal structure. Therefore, the correct answer is karyotype.
7.
The physical distribution of cytoplasmic material into the two daughter cells is called:
Correct Answer
C. Cytokinesis
Explanation
Cytokinesis is the correct answer because it refers to the process of dividing the cytoplasm of a cell into two daughter cells after mitosis. This process ensures that each daughter cell receives a complete set of organelles, cytoplasmic material, and other essential components necessary for their proper functioning. DNA replication is the process of copying DNA molecules, not the distribution of cytoplasmic material. Mitosis refers to the division of the nucleus, not the cytoplasm. Binary fission is a form of cell division in prokaryotes, not eukaryotes.
8.
What of the following cell functions are maintained by cell division?
Correct Answer
A. Growth and reproduction
Explanation
Cell division is a process by which cells reproduce and grow. It is responsible for the growth and development of an organism, as well as the reproduction of cells. During cell division, the genetic material is replicated and divided equally between two daughter cells, ensuring the continuity of life. Therefore, the maintenance of growth and reproduction is a crucial function of cell division. Death, metabolism, movement, and organization are not directly maintained by cell division, although they may be influenced by it.
9.
If a cell has 32 chromosomes prior to the S and undergoes mitosis following by cytokinesis, each new daughter celll with have how many chromosomes?
Correct Answer
B. 32
Explanation
During mitosis, a cell undergoes division resulting in the formation of two identical daughter cells. The process ensures that each daughter cell receives the same genetic material as the parent cell. In this case, the parent cell has 32 chromosomes. Therefore, each new daughter cell will also have 32 chromosomes, as the genetic material is equally distributed between them.
10.
The cell produced by the fusion of an egg and sperm is the
Correct Answer
C. Zygote
Explanation
The correct answer is zygote. A zygote is formed when a sperm fertilizes an egg, resulting in the fusion of their genetic material. This cell is the earliest stage of development and is diploid, meaning it contains a complete set of chromosomes from both the mother and the father. The zygote will undergo cell division and differentiation to form an embryo, which will eventually develop into a fully formed organism.
11.
The point of connection between two sister chromatids before anaphase of mitosis seperates them is called the
Correct Answer
C. Centromere
Explanation
The centromere is the point of connection between two sister chromatids before they are separated during anaphase of mitosis. It is responsible for holding the chromatids together and ensuring their proper alignment and distribution to daughter cells. The centromere plays a crucial role in the accurate segregation of genetic material during cell division.
12.
Sexual reproduction increases genetic variability through all of the following except
Correct Answer
D. Mitosis
Explanation
Mitosis is a type of cell division that results in two identical daughter cells, each having the same genetic material as the parent cell. It does not involve the exchange of genetic material between homologous chromosomes, as seen in crossing over during prophase 1 of meiosis. Additionally, mitosis does not involve the random sorting of chromosomes into daughter cells, as seen in independent assortment during meiosis. Fertilization, on the other hand, combines genetic material from two different individuals, increasing genetic variability. Therefore, mitosis is the only process mentioned that does not contribute to genetic variability through sexual reproduction.
13.
The homologous chromosomes pair up during meiosis 1. Each homologue pairs along its entire length. This process is called
Correct Answer
B. Synapsis
Explanation
During meiosis 1, homologous chromosomes pair up and align along their entire length. This process is called synapsis. Synapsis is important because it allows for the exchange of genetic material between homologous chromosomes, a process known as crossing over. This genetic recombination during synapsis contributes to genetic diversity in offspring. Syngamy refers to the fusion of gametes during fertilization, meiosis is the overall process of cell division that produces gametes, and mitosis is a different type of cell division that produces identical daughter cells.
14.
All of the folloing are processes that promote new genetic combinations except
Correct Answer
D. Mitosis
Explanation
Mitosis is a process of cell division that results in two identical daughter cells with the same genetic information as the parent cell. It does not involve the exchange or recombination of genetic material, unlike crossing over, random fertilization, and independent assortment. These processes promote new genetic combinations by introducing genetic variation through the exchange of genetic material between homologous chromosomes or through the combination of genetic material from two different individuals. Natural selection, on the other hand, acts on existing genetic variations to favor certain traits that increase an organism's fitness. Therefore, mitosis does not promote new genetic combinations.
15.
The uterine lining prolifeates during the female cycle and then sloughs off in the process of
Correct Answer
C. Menstruation
Explanation
During the female cycle, the uterine lining thickens and proliferates in preparation for a potential pregnancy. If fertilization does not occur, the body no longer needs the thickened lining and it is shed through menstruation. This process involves the shedding of the uterine lining, along with blood and tissue, through the vagina. Menstruation typically occurs every 28 days, although the length of the cycle can vary for each individual.
16.
The hormone assayed in the pregnancy test is
Correct Answer
E. HCG
Explanation
The hormone assayed in the pregnancy test is hCG (human chorionic gonadotropin). This hormone is produced by the placenta during pregnancy. It can be detected in the urine or blood of a pregnant woman and is used to confirm pregnancy. hCG levels rise rapidly in the early stages of pregnancy and can be detected as early as 10 days after conception. Therefore, the presence of hCG in a pregnancy test indicates that a woman is pregnant.
17.
The most commonly employed form of birth control in the United States
Correct Answer
C. Sperm blockage with condoms
Explanation
Sperm blockage with condoms is the most commonly employed form of birth control in the United States. Condoms are a barrier method of contraception that prevent pregnancy by blocking the entry of sperm into the vagina. They are readily available, easy to use, and provide protection against both unintended pregnancies and sexually transmitted infections. Condoms are widely used because they are effective, affordable, and have minimal side effects compared to other forms of birth control.