Chapter 8 questions Flashcards
what function does cell division play in an amoeba? what functions does it play in your body?
reproduction; development, growth and repair
why is binary fission classified as asexual reproduction?
because the genetically identical offspring inherit their DNA from a single parent
when does a chromosome consist of two identical chromatids?
when the cell is preparing to divide and has duplicated its chromosomes, but before the duplicates actually separate.
a researcher treats cells with a chemical that prevents DNA synthesis from starting. this treatment would trap the cells in which part of the cell cycle?
G1
you view an animal cell through a microscope and observe dense, duplicated chromosomes scattered throughout the cell. which state of mitosis are you looking at?
prophase (since the chromosomes are condensed but not yet aligned)
contrast cytokinesis in animals with cytokinesis in plants.
in animals, cytokinesis involves a cleavage furrow in which contracting microfilaments pinch the cell in two. in plants, it involves formation of a cell plate, a fusion of vesicles that forms new plasma membranes and new cell walls between the cells.
at which of the three checkpoints do the chromosomes exist as duplicated sister chromatids?
G2, and M checkpoints
what is metastasis?
metatasis is the spread of cancer cells from their original site of formation to other sites in the body
the body cells of elephants have 56 chromosomes. if an elephant skin cell with 56 chromosomes divides by mitosis, each daughter cell will have __ chromosomes.
56
are all of human chromosomes fully homologous?
if female then yes because the sex chromosomes are XX. if you are male then no, X and Y are only partly homologous
imagine you stain a human cell and view it under a microscope. you observe 23 chromosomes, including a Y chromosome. you could conclude that this must be a __ cell take from the organ called the __.
sperm (since it is haploid). testes (since it is from a male)
a cell has the haploid number of chromosomes, but each chromosomes has two chromatids. the chromosomes are arranged singly at the centre of the spindle. what is the meiotic stage?
metaphase II (since the chromosomes line up two by two in metaphase I)
explain how mitosis conserves chromosome number while meiosis reduces the number from diploid to haploid.
in mitosis, the duplication of chromosomes is followed by one division of the cell. in meiosis, homologous chromosomes separate in the first of two cell divisions; after the second division, each new cell ends up with just a single haploid set.
a particular species of worm has a diploid number of 10. how many chromosomal combinations are possible for gametes formed by meiosis?
32; 2n = 10, so n = 5 and 2n = 32
