3 Flashcards
What happens during MITOSIS (prophase, metaphase, anaphase, telophase)?
Mitosis produces two genetically identical daughter cells from a single parent cell. PROPHASE: Chromosomes condense forming two chromatids. Nuclear membrane disintegrates causing the spindle to form. METAPHASE: Spindle organizes condensed chromosomes on the equator of the cell. Some spindle fibers attach to the centromeres and some span the cell. M-checkpoint occurs. ANAPHASE: Some spindle fibers shorten which pull the chromatids apart. Some spindle fibers lengthen which cause the cell to elongate. TELOPHASE: Two new nuclei form.
Independent assortment/random orientation
Independent assortment or random orientation describes how an allele inherited for one gene does not influence which allele is inherited for a different gene.
Binary fission
Binary fission is a type of asexual reproduction that involves a parent cell dividing, resulting in 2 identical cells. The process starts with the parent cell preparing for reproduction by replicating its DNA. Then, the 2 DNA molecules each attach to a different part of the cell membrane and build more membrane to elongate the cell. Then, the cell successfully divides.
Nondisjunction
Nondisjunction is the failure of the non-sister chromatids to separate, which produces daughter cells with abnormal numbers of chromosomes. Nondisjunction can happen during mitosis, meiosis I, or meiosis II.
Outline MEIOSIS I (prophase I, metaphase I, anaphase I, and telophase I)
Meiosis produces 4 cells from a parent cell that divides twice. PROPHASE I: Nuclear membrane dissolves, spindle fibers start to undergo crossing over. METAPHASE I: Paired chromosomes line up at the equator of the cell, a spindle fiber attaches to each pair. ANAPHASE I: Spindle fibers pull the paired chromosomes apart. TELOPHASE I: Paired chromosomes arrive at opposite poles of the cell and nuclear membrane may reform.
Outline MEIOSIS II (prophase II, metaphase II, anaphase II, telophase II)
Meiosis II produces 4 cells from a parent cell that divides twice. PROPHASE II: Nuclear envelope breaks, spindle fibers form between centrosomes. METAPHASE II: Unpaired chromosomes line up at the equator of the cell. ANAPHASE II: Unpaired chromosomes separate and are pulled to opposite poles of the cell. TELOPHASE II: Nuclear membranes begin to reform around new chromosomes, chromosomes decondense.
Biomagnification
Biomagnification occurs when organisms feed on many organisms from the trophic level below them and by doing so, accumulate toxins in their body to a concentration greater than the organisms from the trophic level below them contain.
Greenhouse gasses, the greenhouse effect, and the enhanced greenhouse effect
Greenhouse gasses are gasses found in the atmosphere that contribute to the greenhouse effect. The greenhouse effect refers to the process by which heat is trapped near the Earth’s surface by greenhouse gasses; this can cause the global temperature to rise and contribute to issues such as a decrease in biodiversity and an increase in storms and droughts. The enhanced greenhouse effect is the burning of fossil fuels that contribute to release of the greenhouse gas of carbon dioxide into the atmosphere. Additionally, the most common greenhouse gas is water vapor, along with carbon dioxide, methane, and nitrous oxide.
Shortwave versus longwave radiation
Shortwave radiation is the only radiation from the sun that reaches the Earth’s surface. Longwave radiation is absorbed by greenhouse gasses and re-emitted as heat.
Artery
The artery distributes oxygen-rich blood from your heart to your capillaries. The artery is made up of three layers: the tunica intima, the tunica media, and tunica externa. It is made up of thick walls and a narrow lumen. It has no valves.
Veins
Veins transport blood from the capillaries and return it to the heart. Veins experience lower blood pressure. They are made up of three layers: tunica externa, tunica media, and tunica intima. They are made up of thin walls and a wide lumen. They do contain valves.
Capillaries
Capillaries have permeable walls that allow exchange of materials between tissue cells and blood. Blood flow is slowest in the capillaries, to allow time for this exchange. Capillaries are one-cell thick and contain no valves.
Red blood cells versus white blood cells
Red blood cells transport oxygen, while white blood cells defend the body against disease.
Pulmonary versus systemic circulation
Pulmonary circulation (right side of the heart) transports deoxygenated blood from the heart to the lungs. Systemic circulation (left side of the heart) carries oxygenated blood from the heart to the rest of the body.
Aorta
The aorta is the main and biggest artery that carries oxygenated blood to all parts of the body from the left ventricle. The aorta’s elastic property is helpful when its walls return to their normal shape because the recoil propels the blood forward, maintaining blood pressure.
