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22 Cards in this Set
- Front
- Back
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Why mention fruit flies at all?
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They are abundant and easily obtained for testing. They also have very similar chromosome and gene makeup of larger organisms.
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What are the basic stages of development as depicted during the life cycle of a frog?
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1. Fertilization
• Time (photoperiod&temperature) of year triggers pituitary secrete estrogen hormones →liver produce yolk→ yolk transported to egg (vegetal hemisphere) • Male produce sperm in summer; ready for spring • External 2. Cleavage • Animal hemi cells divides faster than those in vegetal hemi; vegetal hemi cells becomes larger • Blastocoel→ forms in animal hemi 3. Gastrulation • Blastopore → 180˚ from sperm entry • Ectoderm (epidermis,brain,nerves)→mesoderm(connective tissue,blood,heart,skeleton,gonads,kidney)→endoderm/yolk(gut&respiratory) 4. Organogenesis • notochord→ a rod of mesodermal cells in the most dorsal portion of the embryo • ectoderm above it not gonna be epidermis but the nervous system instead • somites: segmented mesodermal tissue adjacent to neural tube & notochord 6. Metamorphosis: larval-maturity • intestines shorten • cartilage skul becomes bony • tadpole horny teeth disappear as frog tongue develops • gills regress and lung enlarge 7. Gametogenesis: development of gametes • meiosis |
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What are the fundamentals of meiosis paying particular attention to creating genetic diversity?
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1. chromosomes replicate prior to cell division; each gene represented 4 times
2. replicated chromosomes(chromatid) held together by kinetochores(centomeres); 4 homologous chromatids pair together 3. 1st meiotic division separates the chromatid pairs from one another 4. 2nd meiotic division splits the kinetochore; each chromatid becomes a chromosome 5. the result is 4 germ cells, each with a haploid nucleus |
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What are the three primary germ layers and major tissues derived from each?
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Ectoderm
• epidermis, brain, nervous system Endoderm • gut and respiratory Mesoderm • blood, heart, kidney, skeleton, gonads, connective tissue, muscles |
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What is the current interpretation of the Principles of von Baer?
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• 1. All developing invertebrates appear to be very similar right after gastrulation
• 2. All vertebrates initially have the sam type of skin • 3. The visceral clefts of embryonic birds and mammals do not resemble the gill slits of adult fish, instead they resemble, visceral clefts of embryonic fish and vertebrates • 4. Human embryos never pass through a stage equivalent to a fish or a bird |
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a map constructed from observing a labeled group of embryonic cells to see outcome as adult organism
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Fate map
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traces fates of different areas of eggs using dyes;Mixed dye with agar, agar chips placed on embryo, dye stained cells
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Vital Dye Staining
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structures tend to have similarities that arise from being derived from a common ancestral structure example is the wing of a bird and the forelimb of a human
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Homolous
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structures similarity comes from performing a similar function not arising from a common ancestor example is a wing of a bird and the wing of a butterfly
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Analogous
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Caused by a genetic mutation in the KIT gene, a potein that is essential for cell proliferation and migration of neural crest cells that do not multiply extensively as they should resulting in under pigmentation, deafness, and gut malformations, nor blood cell precursors causing anemia, or germ cells sterility
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Piebaldism
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an agent such as radiation that causes genetic mutation
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Mutagen
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a substance that is capable of causing cancer in living tissue
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Carcinogen
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an agent or factor that causes malformation of an embryo
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Tetratogen
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caused by exogenous agents and tetratogens such as plants, chemicals, viruses, radiation, hyperthermia
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Disruption
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any defect that an animal or person is born with and can be caused by hereditary, idiopathic (unknown cause) or environmental factors
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Congenital malformation
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performed the procedure of cracking open a chicken egg on each successive day of its three week incubation and noted the formation of major organs, the first embryologist known, seeked to discover how development actually occurred
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Aristotle
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proposed that the heart pumped blood from the atria to the ventricles and that the heart is a pumping organ that circulates blood throughout the body
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Harvey
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did a number of studies on chick embryo development in embryology, produced a series of drawings of the chick embryo as it developed, and also discovered taste buds
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Malpighi
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believe that the organs of the embryo are formed from scratch at each generation- supported by Aristotle and Harvey
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Epigenist
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believe that the organs of the embryo are already present in miniature form within the egg or sperm- supported by Marcello and Malpighi
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Preformationist
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developmental changes that occur when different parts of an organism grow at different rates
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Allometry
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growth occurs at the same rate for all parts of an organism so that it is consistent throughout development
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Isometry
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