1. Fill in the blanks and explain the statements.
a. After complete oxidation of a glucose molecules, —- — — number of ATP molecules are formed.
b. At the end of glycolysis, —- — — molecules are obtained.
c. Genetic recombination occurs in — — — phase of prophase of meiosis-I.
d. All chromosomes are arranged parallel to equatorial plane of cell in — — — phase of mitosis.
e. For formation of plasma membrane, — — — molecules are necessary.
f. Our muscle cells perform — — — type of respiration during exercise.
Answer:-
a. After complete oxidation of a glucose molecule, 36 or 38 ATP molecules are formed
. b. At the end of glycolysis, 2 pyruvate molecules are obtained.
c. Genetic recombination occurs in the pachytene phase of prophase of meiosis-I.
d. All chromosomes are arranged parallel to equatorial plane of cell in metaphase phase of mitosis
e. For formation of plasma membrane, phospholipid molecules are necessary.
f. Our muscle cells perform anaerobic type of respiration during exercise
a. After complete oxidation of a glucose molecule, 36 or 38 ATP molecules are formed.
This is through a process called cellular respiration, which occurs in the mitochondria of cells. Glucose is broken down into smaller molecules through a series of reactions, and the energy released is used to generate ATP molecules, which are the primary energy currency of cells.
b. At the end of glycolysis, 2 pyruvate molecules are obtained.
Glycolysis is the first step of cellular respiration and it happens in the cytoplasm of the cell. It involves the breakdown of one glucose molecule into two pyruvate molecules and the production of 2 ATP and 2 NADH.
c. Genetic recombination occurs in the pachytene phase of prophase of meiosis-I.
During meiosis, the cells undergo two rounds of division that result in four daughter cells with half the number of chromosomes as the parent cell. Meiosis-I is the first stage of meiosis and prophase is the first stage of meiosis-I. The pachytene phase is where genetic recombination occurs between homologous chromosomes.
d. All chromosomes are arranged parallel to equatorial plane of cell in metaphase phase of mitosis.
Mitosis is the process of cell division that results in two identical daughter cells, each with the same number of chromosomes as the parent cell. The chromosomes are replicated during interphase and in the metaphase phase the chromosomes align at the equator of the cell, called the metaphase plate, in preparation for separation.
e. For formation of plasma membrane, phospholipid molecules are necessary.
A plasma membrane is a thin layer of lipids and proteins that surrounds all living cells. It is made up primarily of phospholipids, which are molecules that have a hydrophobic tail and a hydrophilic head. These molecules self-assemble to form a bilayer that acts as a barrier to separate the cell’s interior from its exterior environment.
f. Our muscle cells perform anaerobic type of respiration during exercise.
During exercise, our muscle cells need energy quickly and in large amounts, and the process of cellular respiration cannot keep up with the demand using oxygen alone. Therefore, muscle cells switch to anaerobic respiration which generates energy without the use of oxygen. This process is less efficient than aerobic respiration and produces lactic acid as a by-product which causes muscle fatigue.
2. Write definitions.
a. Nutrition. b. Nutrients c. Proteins. d. Cellular respiration e. Aerobic respiration. f. Glycolysis
Ans:- a. Nutrition refers to the process by which an organism obtains and uses food to maintain growth, repair tissues, and support overall health and well-being.
b. Nutrients are the substances in food that provide the energy and raw materials an organism needs to survive and grow. These include carbohydrates, fats, proteins, vitamins, and minerals.
c. Proteins are large, complex molecules made up of chains of amino acids. They play a vital role in the structure and function of all living organisms, serving as enzymes, hormones, and structural components of cells and tissues.
d. Cellular respiration is the process by which cells convert the energy in food molecules into a form that can be used by the cell, called adenosine triphosphate (ATP). This process occurs in the mitochondria and involves the breakdown of glucose and other molecules to release energy.
e. Aerobic respiration is a type of cellular respiration that uses oxygen to release energy from food molecules. It is a highly efficient process that generates large amounts of ATP.
f. Glycolysis is the first step of cellular respiration, which occurs in the cytoplasm of the cell. It involves the breakdown of one glucose molecule into two pyruvate molecules, and the production of 2 ATP and 2 NADH. This process does not require oxygen and can occur both in the presence and absence of oxygen.
3. Distinguish between
a. Glycolysis and TCA cycle.
b. Mitosis and meiosis.
c. Aerobic and anaerobic respiration
Answer:-
a. Glycolysis and TCA cycle are both steps in the process of cellular respiration, but they are distinct and occur in different locations within the cell.
Glycolysis is the initial step of cellular respiration and it occurs in the cytoplasm of the cell.
It involves the breakdown of one glucose molecule into two pyruvate molecules, and the production of 2 ATP and 2 NADH.
The TCA cycle, also known as the Krebs cycle, is the next step of cellular respiration that occurs in the mitochondria. It converts the pyruvate molecules into acetyl-CoA, which then enters the TCA cycle and produces high-energy molecules such as NADH and FADH2.
These molecules will then be used to generate ATP.
b. Mitosis and meiosis are both types of cell division, but they serve different purposes.
Mitosis is the process of cell division that results in two identical daughter cells, each with the same number of chromosomes as the parent cell.
This is used for growth and repair of tissues.
Meiosis is the process of cell division that results in four daughter cells with half the number of chromosomes as the parent cell.
This is used for the production of sperm and egg cells.
c. Aerobic respiration and anaerobic respiration are both types of cellular respiration, but they differ in the presence or absence of oxygen.
Aerobic respiration is a type of cellular respiration that uses oxygen to release energy from food molecules and it is a highly efficient process that generates large amounts of ATP.
Anaerobic respiration is a type of cellular respiration that does not require oxygen to release energy from food molecules.
It is less efficient than aerobic respiration and produces lactic acid as a by-product which causes muscle fatigue.
4. Give scientific reasons.
a. Oxygen is necessary for complete oxidation of glucose.
Answer:_
a. Oxygen is necessary for complete oxidation of glucose because it is the final electron acceptor in the process of cellular respiration. This means that it accepts the electrons that are transferred during the different stages of cellular respiration, allowing the energy stored in these electrons to be converted into ATP. Without oxygen, the electrons would not be able to be transferred to a final acceptor, and so the energy stored in them would not be able to be harnessed.
b. Fibers are one of the important nutrients.
Answer:-
b. Fibers are one of the important nutrients because they play a vital role in maintaining a healthy digestive system. They help to regulate bowel movements and prevent constipation, lower cholesterol levels, and control blood sugar levels. They also add bulk to the diet, which can help with weight management.
c. Cell division is one of the important properties of cells and organisms.
Answer:–
c. Cell division is one of the important properties of cells and organisms because it allows for growth, repair, and reproduction. During growth, cells divide to increase in number and size. In repair, cells divide to replace damaged or dead cells. In reproduction, cells divide to produce new organisms.
d. Sometimes, higher plants and animals too perform anaerobic respiration.
Answer:-
d. Sometimes, higher plants and animals too perform anaerobic respiration because they do not always have access to a sufficient supply of oxygen. For example, during heavy exercise, the demand for oxygen may exceed the supply, and so the muscle cells have to rely on anaerobic respiration to produce energy. Anaerobic respiration is less efficient than aerobic respiration, but it can still generate some ATP, allowing the muscles to continue contracting.
e. Krebs cycle is also known as citric acid cycle.
Answer:_
e. Krebs cycle is also known as citric acid cycle because it is a series of chemical reactions in which acetyl-CoA is converted into citrate, an intermediate that gives the cycle its name. The citrate is then broken down into smaller molecules, releasing CO2 and generating high-energy molecules such as NADH and FADH2. These molecules will then be used to generate ATP.
5. Answer in detail.
a. Explain the glycolysis in detail.
Answer:– a. Glycolysis is the first stage of cellular respiration and takes place in the cytoplasm. It is the process by which one molecule of glucose is broken down into two molecules of pyruvate, resulting in the production of ATP and NADH. The process can be divided into two phases: the energy-investment phase and the energy-payoff phase.
The energy-investment phase begins with the conversion of glucose into glucose-6-phosphate by the enzyme hexokinase. This reaction is endothermic, meaning it requires energy to proceed. Next, glucose-6-phosphate is converted into fructose-6-phosphate by the enzyme aldolase. This reaction is also endothermic.
The energy-payoff phase begins with the conversion of fructose-6-phosphate into two molecules of pyruvate by the enzyme aldolase. This reaction is exothermic, meaning it releases energy. In this process, two molecules of ATP are consumed to provide the energy required for the conversion. The next step is the conversion of pyruvate into acetyl-CoA by the enzyme pyruvate dehydrogenase, this step produces NADH.
The net gain of glycolysis is two molecules of pyruvate, two molecules of NADH, and two molecules of ATP.
b. With the help of suitable diagrams, explain the mitosis in detail
Answer:_ Mitosis is the process of cell division in eukaryotic cells. It results in the production of two identical daughter cells, each with the same number of chromosomes as the parent cell. The process can be divided into four stages: prophase, metaphase, anaphase, and telophase.
During prophase, the chromatin condenses into chromosomes. Each chromosome is made up of two identical sister chromatids, joined at a centromere. The nuclear envelope breaks down and the spindle apparatus forms.
In metaphase, the chromosomes align at the center of the cell, along an imaginary line called the metaphase plate. The spindle fibers attach to the kinetochores, structures present on the centromeres of the chromosomes.
In anaphase, the chromosomes are pulled apart by the spindle fibers, separating the sister chromatids. Each daughter cell receives one complete set of chromosomes.
In telophase, the chromosomes decondense and the nuclear envelope reforms around the chromosomes. The cell then begins to divide, and the process is complete.
c. With the help of suitable diagrams, explain the five stages of prophase-I of meiosis.
Answer:-
Prophase-I of meiosis is the first stage of meiosis, a type of cell division that results in the production of four genetically different daughter cells, each with half the number of chromosomes as the parent cell. The process can be divided into five stages: leptotene, zygotene, pachytene, diplotene, and diakinesis.
During leptotene, the chromatin condenses into chromosomes, but the sister chromatids are not yet visible.
In zygotene, the homologous chromosomes pair up and synapse, forming a structure called the synaptonemal complex.
In pachytene, the homologous chromosomes exchange genetic material through a process called crossing over. This results in the formation of recombinant chromosomes.
In diplotene, the recombinant chromosomes separate and the synaptonemal complex dissolves.
In diakinesis, the chromosomes are at their most condensed and are visible as distinct structures. The spindle apparatus forms and the cell is ready to enter the next stage of meiosis, meiosis II.
d How all the life processes contribute to the growth and development of the body?
Answer:_ ll life processes, including nutrition, cellular respiration, cell division, and metabolism, contribute to the growth and development of the body.
Nutrition is essential for the body to acquire the necessary nutrients, such as carbohydrates, lipids, proteins, vitamins, and minerals, for growth and development. These nutrients are used for energy production, cell repair and maintenance, and the synthesis of new molecules.
Cellular respiration, specifically the process of converting glucose to ATP, provides the energy necessary for all cellular processes, including growth and development.
Cell division is also necessary for growth and development as it allows for the production of new cells, which can then be used for tissue repair and growth. The process of mitosis and meiosis also plays an important role in genetic diversity and the ability of organisms to adapt to changing conditions.
Metabolism, which is the set of chemical reactions that occur in an organism to maintain life, also contributes to growth and development. These reactions allow for the conversion of nutrients into energy and the synthesis of new molecules that are necessary for growth and development.
Overall, all life processes work together to support the growth and development of the body and allow for the maintenance of life.
e. Explain the Krebs cycle with reaction.
Answer:_
The Krebs cycle, also known as the citric acid cycle or the tricarboxylic acid cycle, is a series of chemical reactions that occur in the mitochondria of cells and is a key part of cellular respiration. This cycle is responsible for the oxidation of acetyl-CoA, which is derived from carbohydrates, lipids, and amino acids, to produce high-energy electrons that are used to generate ATP. The Krebs cycle also produces carbon dioxide and water as byproducts.
During these reactions, electrons are transferred to electron carriers such as NADH and FADH2, and these high-energy electrons are used in the electron transport chain to generate ATP through chemiosmosis. Additionally, carbon dioxide is produced as a byproduct in reactions 2, 4, and 6, and the cycle begins again with the re-entry of oxaloacetate. The cycle also produces water as a byproduct in reactions
5. How energy is formed from oxidation of carbohydrates, fats and proteins? Correct the diagram given below
Answer:_
