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ch 8// exam 2 review
Question | Answer |
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What is the difference between asexual vs sexual reproduction ? | Asexual reproduction is the reproduction that does not involve the union of gametes and in which a single parent produces offspring that are genetically identical to the parent. Sexual reproduction needs gametes |
what is the difference between chromosomes vs chromatids? | A chromosome is made up of two chromatids which are joined by the centromere |
what are gametes? | A haploid cell such as an egg or sperm. Gametes unite during sexual reproduction to produce a diploid zygote |
What is metastasis? | spread of cancer cells to locations distant from their original site |
what is the cell cycle ? | Interphase (G1, G2 and S phase), M phase ( mitosis), and cytokinesis |
what are sister chromatids ? | replicated forms of a chromosome joined together by the centromere and eventually separated during mitosis or meiosis II. |
what is the centromere? | centralized region joining two sister chromatids |
What is mitosis ? | cell division that forms two new cells, each has the same number of chromosomes |
What happens during Interphase ? | period in cell cycle when cell is not dividing. cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase. accounts for 90% of cell cycle. |
What happens during Prophase? | first phase of cell division, chromatin is condensing and mitotic spindle begins to form |
What happens during Metaphase? | second phase of cell division, spindle is complete and the chromosomes are all aligned at the metaphase plate. |
What happens during Anaphase? | third phase of cell division , chromatids of each chromosome have separated and the daughter chromosomes are moving to the poles of the cell |
What happens during Telephase/ cytokensis? | final phase of cell division, daughter cells are forming and cytokinesis has typically begun |
what are nondisjunctions? | pair of homologous chromosomes fail to separate during Meiosis 1 or sister chromatids fail to separate during Meiosis 2. |
What are examples of nondisjunction? | Down syndrome ( extra chromosome) |
What are the differences between Meiosis and Mitosis? | Meiosis produces gamates ( four haploid cells), crossing over occurs. Mitosis produces new somatic cells ( 2 diploids) |
what is the cleavage forrow ? | first sign of cleavage in an animal cell |
What is the cell plate? | double membrane across midline of a dividing plant cell, between the new cells that forms during cytokinesis |
What is the cell cycle control system? | -there is a checkpoint at the end of each phase of cell cycle. , make sure organelles were replicated properly, make sure DNA was replicated properly , check that spindle fibers are ready to pull DNA during anaphase |
what are benign tumors? | mass of abnormal cells that remains at site of origin |
What are malignant tumors? | cancerous tumor that is invasive enough to impair function of one or more organs |
What are somatic cells? | Any cell in a multicellular organism that is not a gamete |
What are autosomes? | non-sex chromosomes; chromosomes 1-22 in humans |
What is a haploid? | a cell with only one complete set of chromosomes |
what are some examples of genetic variation? | Independent assortment, crossover , and random fertilization |
what is independent assortment ? | random distribution of homologous chromosomes during meiosis |
What is a diploid? | cell or organism having two sets of chromosomes (homologous pairs of each chromosome) or twice the haploid number (2n) |