Bio 32.1 Fundamentals of Genetics Lab Post Lab Review PDF

Qualitative variations refer to differences in traits or characteristics that are not measured in numerical terms but rather observed in categories or qualities. These variations are often described in terms of distinct categories or types rather than amounts or degrees. QUALITATIVE VARIATIONS IN...

Qualitative variations refer to differences in traits or characteristics that are not measured in numerical terms but rather observed in categories or qualities. These variations are often described in terms of distinct categories or types rather than amounts or degrees. QUALITATIVE VARIATIONS IN PLANTS scientific name: Hibiscus rosa-sinensis QUALITATIVE VARIATIONS Petal color: Red gumamela, Yellow gumamela, Pink gumamela, White gumamela, and Orange gumamela Flower shape: The gumamela is trumpet-like, with petals that fan outwards in a radial symmetry Flower size: size of gumamela flowers can vary widely depending on the variety, with blooms ranging from medium to large Number of petals: Most gumamela flowers have 5 large, broad petals overlapping, giving the flower its classic open-faced appearance. QUALITATIVE VARIATIONS IN PLANTS scientific name: Caladium spp. QUALITATIVE VARIATIONS Color patterns: The leaves often display a striking combination of colors, including green, white, pink, and red. The central veins are typically colored differently from the rest of the leaf, creating a contrasting pattern, with the edges or margins of the leaf often being a different shade from the central area Sizes: Leaf sizes are generally medium to large. The size can vary depending on the growing conditions Shapes: The leaves are heart-shaped (cordate) or arrowhead-shaped, with broad, smooth, or slightly undulating edges. The tip of the leaf often comes to a sharp point, while the base is rounded or sometimes lobed Number of clefts: Caladium bicolor leaves typically have no deep clefts but may show a slight indentation at the base where the petiole attaches, enhancing the heart-like shape QUALITATIVE VARIATIONS IN PLANTS scientific name: Solanum lycopersicum QUALITATIVE VARIATIONS Color: Typically red when ripe, but can also be yellow, orange, green, or purple, depending on the variety Sizes: Varies from small (cherry tomatoes) to large (beefsteak tomatoes) Shapes: Can be round, oval, or slightly flattened, with some varieties having a more elongated or pear shape Number of locules: Typically 2 to 5, though larger varieties can have more locules Sizes of seeds: Small in length Nature of seeds: Full-seeded, with well-developed seeds, sometimes slightly gelatinous Texture: Smooth skin with fleshy, juicy interior. Some varieties have thinner skin, while others are thicker QUALITATIVE VARIATIONS IN ANIMALS scientific name: Drosophila melanogaster QUALITATIVE VARIATIONS Overall size: Females are generally larger than males, with a more robust body Abdominal size: Males have a smaller, more tapered abdomen, while females have a larger, rounded abdomen Abdominal banding: Both sexes have dark transverse bands on their abdomen, but males often have fewer, more distinct bands near the tip Sex combs on forelegs: Present only in males as small, dark bristles on the first pair of legs (forelegs) Shape of abdominal tip: Males have a more rounded and darker abdominal tip, while females have a pointed, lighter- colored tip External reproductive organ: Males possess visible genitalia at the tip of the abdomen, while females have an ovipositor for egg-laying QUALITATIVE VARIATIONS IN HUMANS TYPES OF FIGERPRINTS The three main types of fingerprints are: 1.Loops: The most common pattern, where ridges enter from one side of the finger, curve around, and exit on the same side. They can be ulnar loops (opening toward the pinky) or radial loops (opening toward the thumb). 2.Whorls: Circular or spiral patterns where ridges form concentric circles or spirals. Whorls have at least two deltas (triangular points). 3.Arches: The least common pattern, where ridges enter from one side of the finger, rise in the center forming an arch, and exit on the opposite side. They can be plain arches (smooth rise) or tented arches (sharper peak). Cells are the fundamental units of living things. They grow and reproduce by means of cell division. They are considered as the common denominator of life and the seats of the vital processes of organisms. Organisms may either be unicellular or multi-cellular. Cells vary in size, shape, and functions, yet have common cell structures. The cells of complex plants and animals differ in several ways, although their basic structures are the same. Differences among cells are usually correlated with the specific task of the cell as part of the organism. It is important to know the cellular features which make plant cells different from animal cells and to determine cellular structures involved in the transmission of traits. PROTIST CELLS scientific name: Amoeba proteus CELLULAR STRUCTURES Cytoplasm: The jelly-like fluid inside the cell that supports the organelles and facilitates movement. It has two layers: the outer, clear ectoplasm and the inner, granular endoplasm Cell membrane: A thin, flexible layer surrounding the cell that controls the movement of substances in and out of the amoeba Nucleus: The control center of the cell that contains genetic material and regulates cell activities. Nucleolus: A small structure within the nucleus responsible for producing ribosomes and assisting in protein synthesis Pseudopodia: Temporary, arm-like extensions of the cell membrane and cytoplasm used for movement and capturing food PROTIST CELLS scientific name: Paramecium sp. CELLULAR STRUCTURES Cytoplasm: The fluid-like substance inside the cell that contains organelles and supports metabolic activities. Cell membrane: A thin, protective layer that surrounds the cell, regulating the passage of substances in and out of the paramecium. Nucleus: The control center of the cell, containing genetic material and managing cell functions. Cilia: Short, hair-like structures covering the surface of the paramecium. They beat in coordinated waves to help the organism move and capture food. PROTIST CELLS scientific name: Euglena sp. CELLULAR STRUCTURE In the image, the flagellum/flagella is a long, whip-like structure extending from the body of the Euglena (the organism in the image). It is used for locomotion, allowing the organism to move through water by propelling itself in a spiral or whipping motion. The flagellum also helps in sensing the environment and directing the Euglena toward light sources, aiding in photosynthesis. ANIMAL CELLS scientific name: Ascaris uterus CELLULAR DIVSION IN THE UTERUS In a cross-section of the Ascaris uterus, you can observe cellular division primarily in the developing eggs. The uterine wall itself typically does not show cellular division, as its main function is to house and transport eggs. The cellular division occurs mainly within the eggs and embryos inside the uterus.  PLANT CELL CELLS scientific name: Allium cepa WET MOUNT WITHOUT STAIN A wet mount of an Allium cepa (onion) is a preparation technique used to observe the cells of an onion under a microscope. Here's how it's typically done: 1.Peel off the onion epidermis: A thin, transparent layer of cells is taken from the inner surface of the onion scale. 2.Place the sample on a microscope slide: The onion epidermis is laid flat on a glass slide. 3.Add a drop of water: Water is added to the sample to keep it hydrated and prevent drying. 4.Cover with a coverslip: A thin glass coverslip is gently placed over the sample to flatten it and allow for better viewing under the microscope. 5.Observe under the microscope: The wet mount allows you to view onion cells, including the cell wall, cytoplasm, nucleus, and sometimes vacuoles.  PLANT CELL CELLS scientific name: Allium cepa WET MOUNT WITH STAIN Staining an Allium cepa (onion) wet mount with acetocarmine is a technique used to make the cell structures, especially the nucleus and chromosomes, more visible under the microscope. Here's how it's typically done: 1.Peel off the onion epidermis: Similar to a regular wet mount, a thin, transparent layer of onion cells is peeled from the inner scale. 2.Place the sample in a watch glass 3.Add a drop of acetocarmine stain: Acetocarmine is a red dye that stains chromatin, making the nucleus and chromosomes more distinct. 4.Heat the slide gently (optional): Sometimes, gentle heating is used to help the stain penetrate the cells better. Care must be taken not to overheat or dry the sample. 5.place the sample on a glass slide 6.Cover with a coverslip: A coverslip is placed over the sample to protect it and flatten it for better viewing. 7.Observe under the microscope: The acetocarmine stain highlights the nucleus and chromosomes, making it easier to observe mitotic stages if the cells are dividing.  PLANT CELL CELLS scientific name: Rhoeo sp. WET MOUNT A wet mount of a Rhoeo sp. (commonly known as Moses-in-the-cradle) leaf is a method to observe its cells under the microscope. The Rhoeo sp. leaf is often used for studying cell structure, particularly stomata, guard cells, and pigment distribution due to its colorful tissue. In this wet mount, you may also observe cytoplasmic streaming (the movement of cytoplasm within the cells) and the overall structure of the cells. PLANT CELLS VS ANIMAL CELLS Karyotyping is the classification of chromosomes into several major groups according to criteria established by some international groups. It uses clear photographs of the entire chromosome complement of a human cell when it is pressed flat during metaphase. A karyotype is done by cutting out each chromosome pair and matching the chromosomes according to length, position of the centromere, and banding patterns. Each pair is assigned a number. In males, one pair is unequal, consisting of a medium-length X chromosome and a very short Y chromosome. A female would have two X’s of equal sizes. Structural aberrations and numerical chromosome changes can be detected using this technique Through karyotyping, we can detect abnormalities in chromosomes, such as numerical abnormalities, where the number of chromosomes deviates from the normal count of 46 in humans. These abnormalities can lead to genetic disorders. The three main types are: 1.Monosomy: One chromosome is missing, resulting in 45 chromosomes instead of 46, as seen in Turner syndrome. 2.Trisomy: An extra chromosome is present, leading to 47 chromosomes, like in Down syndrome (Trisomy 21). 3.Polyploidy: There are additional full sets of chromosomes, such as having 69 chromosomes (triploidy), which is more common in plants but usually not viable in humans. karyotype refers to the complete set of chromosomes in an organism, usually arranged and displayed in a systematic way. A "metaphase spread" is a technique used to prepare a karyotype; it involves arresting cells in metaphase during cell division, staining them, and then arranging the chromosomes for analysis. The metaphase spread allows for detailed examination of chromosome number, structure, and any potential abnormalities. METAPHASE SPREAD EXAMPLES METAPHASE SPREAD EXAMPLES Mitosis is the process of cell division that results in two genetically identical daughter cells, each with the same number of chromosomes as the original cell. It is essential for growth, repair, and asexual reproduction in organisms. Mitosis consists of several stages: 1. Prophase: Chromosomes condense and become visible, the nuclear envelope breaks down, and the mitotic spindle begins to form. 2.Metaphase: Chromosomes line up at the cell's equatorial plane (the metaphase plate) and attach to spindle fibers. 3.Anaphase: The sister chromatids are pulled apart to opposite poles of the cell. 4.Telophase: Chromosomes begin to de-condense, the nuclear envelope reforms around each set of chromosomes, and the spindle fibers disassemble. 5.Cytokinesis: The cytoplasm divides, resulting in two separate daughter cells. One of the most renowned methods for observing mitosis is by preparing stained onion root tip samples. This technique allows us to visualize the different stages of cell division clearly. The process involves several key steps to ensure that the root tips are properly fixed, stained, and examined. Here is a concise overview of the procedure: Select healthy onion bulbs and expose the root tips by scraping the outer scales. Grow in distilled water until roots reach 1-2 cm in length. Collect the roots in the morning (9-10 am) when mitotic activity is high. Fix the roots in a 2:1 ethanol and glacial acetic acid solution for 1 hour. Fixation preserves the state of chromosomes by stabilizing their structure and preventing degradation, which is essential for accurately observing their organization and behavior during mitosis. Wash the fixed roots with distilled water and hydrolyze in 1 N hydrochloric acid for 5 minutes. Stain the roots with 2% acetocarmine for 20-25 minutes. Destain using 45% acetic acid, then squash the roots, mount on glass slides, and examine under a compound microscope. Observe and Document Example of cells undergoing mitosis interphase metaphase cytokinesis prophase telophase anaphase Meiosis is a specialized type of cell division that reduces the chromosome number by half, producing four genetically diverse haploid cells from one diploid cell. It is crucial for sexual reproduction and occurs in two main stages: Meiosis I and Meiosis II. Meiosis I: 1. Prophase I: Chromosomes condense, homologous chromosomes pair up and exchange genetic material through crossing over, and the nuclear envelope dissolves. (read the detailed process of prophase I in your manual) 2.Metaphase I: Homologous chromosome pairs align at the metaphase plate. 3.Anaphase I: Homologous chromosomes are pulled to opposite poles of the cell, with each chromosome still consisting of two sister chromatids. 4.Telophase I: Chromosomes arrive at the poles, and the cell undergoes cytokinesis, resulting in two haploid cells, each with half the original chromosome number but with chromosomes still consisting of two sister chromatids. Meiosis is a specialized type of cell division that reduces the chromosome number by half, producing four genetically diverse haploid cells from one diploid cell. It is crucial for sexual reproduction and occurs in two main stages: Meiosis I and Meiosis II. Meiosis II: 1. Prophase II: Chromosomes condense again, and a new spindle apparatus forms in each of the two haploid cells. The nuclear envelope dissolves if it was reformed. 2.Metaphase II: Chromosomes line up at the metaphase plate in each of the two haploid cells. 3.Anaphase II: The sister chromatids of each chromosome are separated and pulled to opposite poles of each cell. 4.Telophase II: Chromosomes arrive at the poles, and nuclear envelopes reform around each set of chromosomes. Cytokinesis occurs, resulting in four genetically unique haploid cells. Each of these four cells has half the number of chromosomes of the original cell and is genetically distinct due to the processes of crossing over and independent assortment. Example of cells undergoing meiosis