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19 Cards in this Set
- Front
- Back
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In animals, autosomal cells are said to be _______ and have two copies of each chromosome. In humans this number is _______. Germ cells are _______ and have one copy of each chromosome. In humans this number is _______. |
diploid (2n) 46 haploid (n) 23 |
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The cell cycle contains five stages. The G1, S and G2 stages are collectively called _______, during which the DNA is uncoiled in the form of ______. The G1 stage is also called _______. In this stage ________. The S stage is also called _______. In this stage ________. The G2 stage is also called _______. In this stage ________. The M stage is also called _______. In this stage _______. In the G0 stage _______. |
interphase chromatin presynthetic gap cells create organelles for energy and protein production, while also increasing their size; a restriction point, during which the DNA is checked for quality, must be passed for the cell to move into the S stage synthesis DNA is replicated; the identical strands of DNA, called chromatids, are held together at the centromere postsynthetic gap there is further cell growth and replication of organelles in preparation for mitosis; another quality checkpoint must be passed for the cell to enter into mitosis. mitosis mitosis and cytokinesis occur the cell performs its function without any preparation for division |
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The protein _______ plays a role in the two major checkpoints of the cell cycle (G1 to S, and G2 to M) |
p53 |
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_______ rise and fall during the cell cycle. _______ bind to _______, phosphorylating and activating _______ for the next stage of the cell cycle. |
cyclins and cyclin-dependent kinases (CDK) cyclins CDKs transcription factors |
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Cancer-causing genes can often be classified into _______ (genes that, when mutated, actively promote cell division) and _______ (genes, when mutated, lose their ability to regulate or pause the cell cycle). |
oncogenes tumor suppressor genes |
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Mitosis has four phases: In ________, the chromosomes condense, nuclear membrane dissolves, nucleoli disappear, centrioles migrate to opposite sides of the cell, and the _______ begins to form. The _______ of each chromosome is contacted by a _______. In _______, chromosomes line up along the _______. In _______, sister chromatids are separated and pulled to opposite poles. In _______, the nuclear membrane reforms, spindle apparatus disappears, and cytosol and organelles are split between the two daughter cells through _______. |
prophase spindle apparatus kinetochore spindle fiber metaphase metaphase plate (equatorial plate) anaphase telophase cytokinesis |
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Meiosis occurs in _______ and produces up to four nonidentical _______. |
gametocytes (germ cells) haploid sex cells (gametes) |
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Meiosis has one round of replication and two rounds of division called _______. |
reductional and equational divisions |
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In ________, homologous pairs of chromosomes (homologues) are separated from each other. _______ are chromosomes that are given the same number, but are of opposite parental origin. In ________, the same events occur as in mitosis, except that homologues come together and intertwine in a process called _______. The four chromatids are referred to as a _______, and _______ exchanges genetic material from one chromatid with material from a chromatid in the homologues chromosome. Crossing over explains Mendel's _______. In _______, homologous chromosome line up on opposite sides of the metaphase plate. In ______, homologous chromosomes are segregated to opposite poles of the cell. This accounts for Mendel's ______. In _______, the chromosomes may or may not fully decondense, and the cell may enter ______, when they partially uncoil, after cytokinesis. |
meiosis I homologues prophase I synapsis tetrad crossing over second law (of independent assortment) metaphase I anaphase I first law (of segregation) telophase I interkinesis |
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In ______, sister chromatids are separated from each other in a process that is functionally identical to mitosis. _______ are copies of the same DNA held together at the centromere. |
meiosis II sister chromatids |
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The Y chromosome carries little genetic information, but contains the _______, which causes the gonads to differentiate into testes. |
SRY (sex-determining region Y) gene |
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The male reproductive system contains both internal and external structures. Sperm develop in the _______ in the _______. They are nourished by _______. _______ secrete testosterone and other male sex hormones (androgens). The testes are located in the ______, which hangs outside of the abdominal cavity and has a temperature 2 to 4 degrees Celsius lower than the body. Once formed, sperm gain motility in the ______ and are stored there until ejaculation. During ejaculation, sperm travel through the ______ to the ______ to the ______ and out through the penis. The _______ contribute fructose to nourish sperm and produce alkaline fluid. The _______ also produces alkaline fluid. The _______ produce a clear viscous fluid that cleans out any remnants of urine and lubricates the urethra during sexual arousal. Semen is composed of _______ from the glands above. |
seminiferous tubules testes Sertoli cells interstitial cells (of Leydig) scrotum epididymis vas deferens ejaculatory duct urethra seminal vesicles prostate gland bulbourethral glands sperm and seminal fluid |
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In spermatogenesis, four haploid sperm are produced from a ______. After S stage, the germ cells are called _______. After meiosis I, the germ cells are called ______. After meiosis II, the germ cells are called _______. After maturation, the germ cells are called ______. |
spermatogonium primary spermatocytes secondary spermatocytes spermatids spermatozoa |
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Sperm contain a: _______, which contain the genetic material and is covered with an _______ (a modified Golgi apparatus that contains enzymes that help the sperm fuse to and penetrate the ovum). _______, which generates ATP from fructose and contains many mitochondria. _______, which promotes motility. |
head midpiece flagellum |
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The female reproductive system only contains internal structures. ______ (eggs) are produced in ______ in the ______. Once each month, an egg is ovulated into the ______ and is drawn into the ______. The fallopian tubes are connected to the ______, the lower end of which is called the ______. The ______ lies below the cervix and is the site where sperm are deposited during intercourse. Birth also occurs through the ______. The external female anatomy is known as the _______. |
ova follicles ovaries peritoneal sac fallopian tube oviduct uterus cervix vaginal canal vaginal canal vulva |
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In _______, one haploid ovum and a variable number of polar bodies are formed from an _______. At birth, all oogonia have already undergone replication and are considered ______ They are arrested in ______. The ovulated egg each month is a _______, which is arrested in ______. If the oocyte is fertilized, it will undergo _______ to become a true ovum. _______ is uneven in oogenesis. The cell receiving very little cytoplasm and organelles is called a ______. Oocytes are surrounded by the _______, an acellular mixture of glycoproteins that protect the oocyte and contain the compounds necessary for sperm binding, and the _______, which is a layer of cells that adhered to the oocyte during ovulation. |
oogensis oogonium primary oocytes prophase I secondary oocyte metaphase II meiosis II cytokinesis polar body zona pellucida corona radiata |
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_______ from the hypothalamus causes the release of _______, the functions of which depend on the sex of the individual. In males, ______ stimulates the Sertoli cells and triggers spermatogenesis, while ______ causes the interstitial cells to produce testosterone. Testosterone is responsible for the maintenance and development of the male reproductive system and male secondary sex characteristics (facial and axillary hair, deepening of the voice, and changes in growth patterns). In females, ______ stimulates development of the ovarian follicles, while ______ causes ovulation. |
Gonadotropin-releasing hormone (GnRH) follicle-stimulating hormone (FSH) and luteinizing hormone (LH) FSH LH FSH LH |
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The menstrual cycle is a periodic growth and shedding of the _______. In the _______, GnRH secretion stimulates FSH and LH secretion, which promotes follicle development. Estrogen is released, stimulating vascularization and glandularization of the _______. ______ is stimulated by a sudden surge in LH. This surge occurs because _______ stops having negative feedback effects at a certain threshold and begins to have positive feedback effects. In the _______, LH promotes the ruptured follicle to become the _______, which secretes progesterone that maintains the uterine lining. High estrogen and progesterone levels cause negative feedback on _______. Menstruation occurs if there is no fertilization. As the ______ levels drop, the endometrial lining is sloughed off, and the block on ______ production is removed. If fertilization does occur, the blastula produces _______ which, as an LH analogue, can maintain the corpus luteum. Near the end of the first trimester, _______ levels drop as the placenta takes over progesterone production. |
endometrial lining follicular phase decidua ovulation estrogen luteal phase corpus luteum GnRH, LH and FSH estrogen and progesterone GnRH human chorionic gonadotropin (hCG) hCG |
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Menopause occurs when the ovaries stop producing ______, usually between the ages 45 and 55. Menstruation stops and _______ levels rise. Physical and physiological changes accompanying menopause include flushing, hot flashes, bloating, headaches, and irritability. |
estrogen and progesterone FSH and LH |
