Xuống cuối trang

Tài nguyên dạy học

Điều tra ý kiến

Người đang truy cập vào Diễn đàn của Trường THPT Nam Sách II là ai?
Một cựu học sinh
Một học sinh đang học
Một giáo viên của trường
Một giáo viên trường khác
Một học sinh trường khác

Thống kê

  • truy cập   (chi tiết)
    trong hôm nay
  • lượt xem
    trong hôm nay
  • thành viên
  • xin chào bạn:

    0 khách và 0 thành viên


    Chào mừng quý vị đến với Trường THPT Nam Sách II - Hải Dương

    Quý vị chưa đăng nhập hoặc chưa đăng ký làm thành viên, vì vậy chưa thể tải được các tài liệu của Thư viện về máy tính.
    Nếu chưa đăng ký, hãy nhấn vào chữ ĐK thành viên ở phía bên trái, hoặc xem phim hướng dẫn tại đây
    Nếu đã đăng ký rồi, quý vị có thể đăng nhập ở ngay phía bên trái.

    Tai lieu tham khao Sinh học 12

    • Begin_button
    • Prev_button
    • Play_button
    • Stop_button
    • Next_button
    • End_button
    • 0 / 0
    • Loading_status
    Nhấn vào đây để tải về
    Báo tài liệu có sai sót
    Nhắn tin cho tác giả
    (Tài liệu chưa được thẩm định)
    Nguồn: Sưu tầm
    Người gửi: Đỗ Văn Mười (trang riêng)
    Ngày gửi: 14h:07' 31-07-2010
    Dung lượng: 4.2 MB
    Số lượt tải: 149
    Số lượt thích: 0 người
    XO Turner Syndrome
    Female phenotype
    Short stature
    Webbing of the neck
    Small, widely-spaced nipples
    XXY Klinefelter Synd. Features:
    Often unusually tall; long arms and legs
    Breast development
    Underdeveloped testes
    Hypophosphatemia: example of X-linked dominant inheritance
    Symptoms: short stature, bow-legs, lowered phosphate levels in blood
    males transmit trait to none of their sons and all of their daughters
    females transmit trait similar to autosomal dominant
    5 ft
    45, X0 – Turner syndromes
    Total fetal
    normal intelligence;
    may have 3D spatial problems
    or math problems.
    99% of cases
    – aborted
    1 in 2,500 or
    1 in 2,000
    liveborn females. topic.asp?hwid=zm2596
    Gynecomastia –
    Male with female features
    small testes,
    inability to produce sperm
    Mental retardation
    is related directly to the number
    of supernumerary X chromosomes
    (-15 IQ unit per 1 extra X).
    47, XXY – Klinefelter syndrome – or even 47, XXXY etc….
    1 out of 500 or 1000 males;
    most go through life undiagnosed
    40% of embryos survive to birth
    Cleft Palate...
    In addition to needing plastic surgery to repair the opening, these children may have problems with their feeding and their teeth, their hearing, their speech, and their psychological development as they grow up.
    Medical and technology advances have been invaluable in the treatment of the cleft lip and palate. Clefts occur 1 time in 1,000 births in Caucasians, more often in Asians and Native Americans, and less often in African Americans.
    Fetal Alcohol Syndrome...
    Fetal Alcohol Syndrome (FAS) and Fetal Alcohol Effects (FAE) are growing problems in the United States. Despite the warnings posted in bars and restaurants and the increased media attention given to the perils of alcohol use during pregnancy, the rate of drinking among women of childbearing age continues to rise. The incidence of FAS may be as high as 12,000 per year, with FAE evident in up to 36,000 infants per year. Drinking during pregnancy affects not only the mother, but also the growing fetus. Alcohol can cause physical deformities and neurobehavioral deficits in the infant and growing child. Thus, it is not surprising that FAS is the leading cause of mental retardation and the only one that is preventable.
    ANY consumption of alcohol during ANY time during the gestation period can damage a baby’s brain.
    For example, sickle-cell disease is caused by a mutation of a single base pair in the gene that codes for one of the polypeptides of hemoglobin.
    A change in a single nucleotide from T to A in the DNA template leads to an abnormal protein.
    Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
    FISH analysis (Fluorescent in situ hybridization) -- translocation MOL_ZYTO/imageAU9.JPG
    FITC or Fluorescein (green),
    Texas-red (red),
    Rhodamine (red),
    DAPI (blue)
    Green + RED = YELLOW
    FISH analysis (Fluorescent in situ hybridization) --DELETION
    Two green, two reds
    on different chromosomes
    – no deletion
    Two green, one red –
    One red is deleted.
    Interphase FISH, relaxed chromatin
    Size of deletion can not be estimated.
    Deletion size is smaller
    than distance to green signal (probe)
    The First HapMap Success Story:
    Age-Related Macular Degeneration
    Two other risk variants have
    been identified in the last two months.

    Together these account for 74%
    of risk, and point to powerful
    new approaches to prevention
    and treatment.
    XY sex determination X-Y chromosomes
    SRY locus
    Described in text, p. 283
    All patients with same diagnosis
    Grey: Normal responder.
    Orange: Toxic responder. Blue: Non-responder.
    Treat with conventional
    drug or dose
    Responders and patients
    not predisposed to toxicity
    All patients with same diagnosis
    Treat with alternative
    drug or dose
    and toxic responders
    Evans, Johnson. Annu Rev Genomics Hum Genet 2001.
    Dosage Compensation Mechanism for X-Linked Genes in Mammals

    1. Gene dosage varies between the sexes in mammals, because females have two copies of X while males have one. Early in development, gene expression from the X chromosome must be equalized to avoid death. Different dosage compensation systems have evolved in different organisms.
    2. In mammals, female somatic cell nuclei contain a Barr body (highly condensed chromatin) while male nuclei do not. The Lyon hypothesis explains the phenomenon:
    a. Barr body is a condensed and (mostly) inactivated X chromosome. Lyonization of one chromosome leaves one transcriptionally active X, equalizing gene dose between the sexes.
    b. An X is randomly chosen in each cell for inactivation early in development (in humans, day 16 postfertilization).
    What is unusual about the following pedgree?
    Males pass on the trait to all males: holandric, or Y-linked inheritance
    Only males are affected
    But affected males do not transmit trait to all sons
    trait can be transmitted via females
    An example of SEX-LIMITED trait: inherited as an autosomal dominant, but only one sex shows trait
    Example: Precocious Puberty
    Sex-Limited Traits
    Fetal Alcohol Syndrome...
    Facial characteristics that suggest the diagnosis of FAS.
    The rarest form of spina bifida is when the spinal tissue actually protrudes from the body. This only occurs in 10% of all cases.
    Spina Bifida...
    Various degrees of leg and foot deformities are found in spina bifida patients, depending on the size of the improper spinal closure.
    Normally within the brain there are some cavities named ventricles, where a liquid known as Cerebrospinal Fluid (CSF) is produced. The purpose of this is to protect the brain and spinal cord, acting as a shock absorber. It also carries away disposed materials. The CSF circulates from the ventricles towards a space that exists between the brain and the membranes (meninges) that surround it, from where it is "eliminated", into the blood stream.
    In the individual with hydrocephalus, the fluid does not drain away properly, but accumulates.
    In an infant, the seams of the skull have not yet fused, so the skull gets bigger as the fluid accumulates.
    DNA Methylation and Cancer
    Robertson KD. DNA methylation and human disease. Nat Rev Genet 2005
    Dynamic Domains
    Kosak ST. Gene Order and Dynamic Domains. Science 2004
    Gleevec™ – Specifically Targets
    An Abnormal Protein, Blocking
    Its Ability To Cause Chronic Myeloid Leukemia
    Multiple mutations lead to colon cancer
    Genetic changes --> tumor changes
    Tumor Progression
    Gửi ý kiến