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Bio 101 Chapter 12
Terms in this set (37)
What is the difference between asexual and sexual reproduction?
Sexual reproduction generates new combinations of traits in fewer generations than does asexual reproduction
Explain the purpose of meiosis
is to reduce the normal diploid cells
What are the phases of meiosis?
Two successive nuclear divisions occur, Meiosis I (Reduction) and Meiosis II (Division). Meiosis produces 4 haploid cells
How are mitosis and meiosis similar?
Both processes include the breakdown of the nuclear membrane, the separation of genetic material into two groups, followed by cell division and the reformation of the nuclear membrane in each cells.
How are mitosis and meiosis different?
Meiosis has two rounds of genetic separation and cellular division while mitosis only has one of each.
replicate genetic material and split into 2 cells
Asexual Reproduction advantages
Conservation of energy & resources
Asexual Reproduction disadvantages
during environmental change
fusion of sex cells produces next generation
Sexual Reproduction advantages
Genetic diversity is extremely advantageous during
Sexual Reproduction disadvantages
Energetically expensive sperm/egg production, mate
attraction, & parental care
A pair of chromosomes having the same gene sequences, each derived from one parent
non-reproductive cells- of humans and other sexually reproducing organisms are diploid
are regions in an organism's DNA that encode information about heritable traits
are different forms of the same gene
gives rise to gametes
Sexual reproduction involves the fusion of reproductive cells from two parents
when two haploid gametes (one egg and one sperm) fuse to form a zygote
Prophase I, Metaphase I, Anaphase I, Telophase I
replicated chromosomes condense, homologs pair, crossing over occurs, spindle forms
paired homologs line up and down the center of the cell
chromosomes reach opposite poles
Prophase II, Metaphase II, Anaphase II, Telophase II
chromosomes condense again
chromosomes line up
sister chromatids split
chromosomes reach opposite poles, nuclear envelope reforms
total of 4 new cells
At end of meiosis and cytokinesis
4 haploid cells
3 Mechanisms that generate variability
Random alignment of chromosome pairs Random fertilization
Gamete formation in plants
plants use meiosis to produce spores
Diploid bodies with specialized structures that form spores (haploid cells) that give rise to gametophytes through mitosis
A multicelled haploid body inside which one or more gametes form
Gamete formation in animals (male)
Meiosis of primary spermatocytes produces four haploid spermatids, which mature into sperm
Gamete formation in animals (female)
Meiosis of a primary oocyte forms cells of different sizes; the secondary oocyte gets most of the cytoplasm and matures into an ovum (egg); other cells (polar bodies) get little cytoplasm and degenerate
A gene that normally acts to restrain the growth of cells in the breast but which, when mutated, predisposes to breast cancer.
THIS SET IS OFTEN IN FOLDERS WITH...
Bio Chapter 1 terms
BIO chapter 2 terms
Bio Chapter 3
Bio 101 Chapter 11
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