Term
| how many pairs of chromosomes do humans have? |
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Definition
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Term
| how many total chromosomes do humans have? |
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Definition
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Term
| how many pairs of autosomes do we have? |
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Definition
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Term
| how many pairs of sex chromosomes do we have? |
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Definition
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Term
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Definition
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Term
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Definition
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Term
| what are the 2 major functions of meiosis? |
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Definition
1. reducing chromosome number
2. shuffling chromosomes in the cell to produce genetically different combinations |
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Term
| what are homologous chromosomes? |
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Definition
| members of a pair of chromosomes |
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Term
true or false:
homologues are the same as homologous chromosomes. |
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Definition
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Term
true or false:
homologues have the same size, shape, and construction. |
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Definition
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Term
true or false:
homologues contain different genes for the same traits. |
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Definition
false-
homologues contain the same genes for the same traits. |
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Term
true or false:
the human life cycle involves only mitosis. |
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Definition
| false- the human life cycle involves both mitosis and meiosis |
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Term
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Definition
| produces sperm in the testes |
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Term
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Definition
| produces eggs in the ovaries |
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Term
| what do the sperm and egg join to form? |
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Definition
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Term
mitosis or meiosis?:
reduces the # of chromosomes from diploid to haploid. |
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Definition
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Term
mitosis or meiosis?:
involved in continued growth of a child |
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Definition
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Term
mitosis or meiosis?:
involved in the repair of tissues throughout life |
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Definition
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Term
mitosis or meiosis?:
results in 4 daughter cells |
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Definition
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Term
| how many divisions are in meiosis? |
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Definition
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Term
| what happens during meiosis I? |
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Definition
1. homologous pairs line up during synapsis resulting in tetrad
2. homologous chromosomes of each pair then separate |
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Term
| what happpens during meiosis II? |
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Definition
1. no duplication of chromosome
2. chromosomes are dyads composed of 2 sister chromatids
3. sister chromatids are separated
4. 2 daughter nuclei separate |
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Term
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Definition
| when homologous chromosomes pair up |
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Term
| how many chromosomes are contained within each tetrad? |
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Definition
| each tetrad consists of 2 chromosomes |
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Term
| within each tetrad, there are 2 chromosomes. how many chromatids are contained in each chromosome? |
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Definition
| 2 chromatids are contained in each chromosome, so there are a total of 4 chromatids within each tetrad |
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Term
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Definition
| when homologous chromosomes may exchange genetic material |
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Term
| what happens as a result of crossing-over? |
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Definition
| increases the variability of the gametes and their offspring |
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Term
| why is meiosis important? |
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Definition
| so that the # of chromosomes remain constant in each new generation |
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Term
| what are the 4 phases of meiosis? |
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Definition
1. prophase
2. metaphase
3. anaphase
4. telophase |
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Term
| meiosis requires ____ nuclear division(s); mitosis requires _____ nuclear division(s) |
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Definition
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Term
| meiosis produces ____ daughter cells; mitosis produces ____ daughter cells |
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Definition
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Term
| following meiosis, the 4 daughter cells have _____ the chromosome # as the parent cell; following mitosis, the daughter cells have ______ # of chromosomes as the parent cell |
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Definition
meiosis = 1/2
mitosis = the same |
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Term
| following meiosis, the daughter cells _____ genetically similar to each other and the parent cell; following mitosis, the daughter cells ______ genetically similar to each other and the parent cell |
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Definition
meiosis = aren't
mitosis = are |
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Term
meiosis or mitosis?:
only occurs at cetain times of the life cycle of sexually reproducing organisms and only in specialized tissues |
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Definition
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Term
meiosis or mitosis?:
occurs in all tissues during embryonic growth |
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Definition
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Term
meiosis or mitosis?:
occurs during cell growth and repair |
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Definition
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Term
| when does nondisjunction occur? |
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Definition
| meiosis I (both members of a pair go into the same daughter cell) and meiosis II (sister chromatids fail to separate) |
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Term
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Definition
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Term
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Definition
| single copy of a chromosome |
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Term
| down syndrome is a mutation of which chromosome? |
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Definition
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Term
| what causes down syndrome? |
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Definition
| trisomy (or 3 copies) of the 21st chromosome |
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Term
| at what age does a woman's chance for producing a child with trisomy 21 increase? |
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Definition
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Term
true or false:
a human can only have too many X and Y chromosomes. |
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Definition
| false- a human can have too few or too many X and Y chromosomes |
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Term
true or false:
a baby born with an abnormal # of sex chromosomes is more likely to survive than a baby born with an abnormal # of autosome chromosomes. |
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Definition
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Term
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Definition
| contain an extra X chromosome; become inactivated |
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Term
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Definition
| absence of second sex chromosome; affects females (X_) |
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Term
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Definition
| extra X inactivated as Barr body; affects males (XXY) |
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