Photosynthesis, Respiration, Reproduction & Stimuli Response
Photosynthesis and Cellular Respiration
1. What is Photosynthesis and Cellular Respiration?
Photosynthesis: It is a process carried out by living organisms, such as plants, algae, and some bacteria, to synthesize organic molecules from inorganic molecules absorbed from the environment, using the sun’s energy. Photosynthesis primarily takes place in the leaves and stems where chlorophyll is present.
Cellular Respiration: It is a process of decomposition of glucose molecules to release energy, which requires oxygen. Cellular respiration occurs in most living beings.
Mitochondria: These are specialized organelles within eukaryotic cells where cellular respiration takes place.
2. Differences Between Breathing and Cellular Respiration, Respiration and Fermentation, and Cellular Respiration and Fermentation
Cellular respiration takes place within cells through mitochondria, while breathing involves a whole apparatus (lungs, bronchi, gills, or trachea, depending on the animal) that brings oxygen from the outside and distributes it through the blood to all body tissues.
Respiration is aerobic because it uses oxygen to break down glucose molecules. Fermentation is anaerobic because it does not use oxygen to break down glucose molecules.
Differences Between Cellular Respiration and Fermentation
Cellular respiration is aerobic and uses oxygen to break down glucose molecules. Fermentation does not use oxygen to break down glucose molecules, so it is anaerobic.
Plant and Animal Responses to Stimuli
3. How do Plants and Animals React to Chemical, Mechanical, and Light Stimuli?
Plants: Plants react to mechanical stimuli such as gravity, contact, and pressure. They respond to chemical stimuli by detecting the presence of water and other minerals for food. They also have the ability to detect light or exhibit light sensitivity.
Animals: Animals respond to chemical stimuli through smell and taste, and to light through their eyes. All these sensations are processed by the nervous system.
Both plants and animals have different responses to the stimuli they receive, including changes in vital activity, movement, and secretion of substances.
Asexual Reproduction in Plants and Animals
4. Explain the Difference Between Asexual Reproduction in Plants and Animals
In plants, asexual reproduction is also called vegetative reproduction. The progenitor cells responsible for producing the offspring are called vegetative units. In organisms such as algae, the process is called binary fission, which is the division of the progenitor into parts that develop into different individuals.
Animals with simpler structures are those that reproduce asexually (e.g., jellyfish, starfish). This occurs by fragmentation, where an individual forms from a part of an organism, or by budding, which is the formation of an individual from a bud or small portion of the parent body that detaches when it finishes developing. It may also remain connected to the parent.
Reverberation, Absorption, and Reflection
5. Why can objects lead to problems of reverberation?
Because objects are very close to each other.
What do absorbent materials prevent?
They absorb sound waves and prevent their reflection.
What is diffuse reflection?
It is when the surface reflecting the image is irregular, and beams of light rays are reflected in different directions.
What can waves do in addition to bypassing obstacles?
Reflect on them.
Convex vs. Concave Lenses
What is the difference between convex lenses and concave lenses for light?
Concave lenses are thicker at the edges than in the middle and scatter light rays. In contrast, convex lenses are thicker in the middle than at the edges and focus light rays.