bio exam one :p

Describe the female reproductive endocrine axis, including endocrine and target organs, hormones, and positive and negative feedback regulating estradiol and progesterone synthesis

-GnRh from the hypothalamus stimulates the pituitary gland to produce LH and FSH. -LH produces the testosterone, in which FSH converts the testosterone to estrogen in the inner layer of the follicle cells. -estradiol has a postive feedback on on pituitary glands which cause an LH surge. during the LH surge, estradiol begins to decrease while progestorone continues to increase.. -during luteal phase, the negative feedback from progestrone suppresses estrogen, while P keeps increasing

Define ovarian cycle

2 phases: follicular -GnRh from hypothalamus stimulates the production of LH and FSH from pituitary. -LH and FSh stimluate the estradiol production (positive feedback) -LH surge triggers ovulation, beginning luteal phase. luteal -LH stimulates ovulation -the conversion of follicle cells to corpus luteum -progesterone production continues; if production doesnt occur the corpus luteam shrivels into corpus albanis

Name the products of meiosis and describe their chromosome content and their genetic make-up compared to each other

4 gamete cells; 23 chromosomes each. the genetic makeup is different from each other because of the alleles of each gene that resulted from DNA crossover.

Explain what occurs during crossing over

DNA from one chromosome is exchanged with another.

Explain why the number of alleles per gene in an individual can be different from the number of alleles per gene in a population

Due to multiple alleles, three or more alternative forms of a gene (alleles) can occupy the same locus; however, only two of the alleles can be present in a single organism.

Identify the key steps during meiosis that result in genetically different daughter cells from the same parent cell

Independent segregation and crossing over result in genetically different daughter cells.moi

Name the phases of meiosis II, describe the events of each phase, identify the ploidy level of cells at the end of meiosis II.

PROPHASE II- spindle fibers form towards chromosomes once again METAPHASE II- single chromosomes align along the equator ANAPHASE II- spindle fibers pull apart sister chromatids TELOPHASE II- 4 new cells formed

Define chromosome

a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.

Compare and contrast asexual and sexual reproduction: including genetic similarity or difference between parents and offspring and among offspring, advantages and disadvantages of each mode.

asexual reproduction: mitosis produces the cells; genetically identical to the parent (clones) sexual reproduction: meiosis produces the cells; genetically similar to the parents (gametes)

Explain how chromosomes move along spindle & where spindle attaches

chromosomes orient themselves randomly at the equator. the spindle fibers (microtubules) attach to the centromere of each chromosome.

Identify dominant, recessive, co-dominant, wild-type, mutant, and sex-linked modes of inheritance from the notation

dominant: A recessive: a co-dominant: mutant: wild-type: sex linked:

Define gene and allele. Know how many alleles an individual diploid organism can have for each locus.

gene: sections of DNA that determine characteristics and traits allele: different versions of the same gene diploids have 2 alleles of every gene.

Indicate when homologous chromosomes separate and when sister chromatids separate during meiosis.

homologous chromosomes separate during anaphase I; sister chromatids separate during anaphase II.

Define Mendel's Law of segregation & explain its physical basis in chromosome movement during Anaphase I.

law of segregation: during the development of the gamete, each gene is segregated in such a way that the gamete consists of just one allele for that gene. physical basis: segregation of homologous chromosomes in anaphase I

Name the phases of meiosis I, describe the events of each phase, identify the ploidy level of cells at the end of meiosis I.

meiosis 1: prophase I, metaphase 1, anaphase 1, telophase 1. PROPHASE 1- replicated homologous chromosomes attach to each other and cross over. METAPHASE 1- chromosomes line up in the middle of the cell. centrioles have spindle fibers that attach to centromere ANAPHASE 1- spindle fibers pull away chromosomes TELOPHASE 1- 2 newly formed nuclei, 2 new formed cells through cytokinesis (splitting of cell) ploidy level: 1n. (23 chromosomes)

Know the outcome of mitosis v meiosis: daughter cells are genetically identical to or genetically different from parent cell?

mitosis: the same meiosis: different

Identify organs in which meiosis occurs

occurs testes and ovaries.

Describe the mechanisms of sexual reproduction, including gamete (and spore) production, fertilization, and embryo protection in -Protists -Plants -Animals

plants: alternations of generations; SEXUAL REPRODUCTION includes the 2 multicellular stages. animals: [sexual] 2 haploid cells make a diploid zygote through meiosis

Define the terms: ploidy, haploid, and diploid

ploidy: the number of set of chromosomes in a cell haploid: one set of chromosomes diploid: 2 sets of chromosomes

Describe the mechanisms of asexual reproduction in: -Prokaryotes -Protists -Plants -Animals

prokaryotes: reproduce through binary fission. (replicating and splitting of DNA into two new cells) protists: [unicellular] life cycles alternate btwn sexual and asexual reproduction, where environmental challenges prompt sexual reproduction. [multicellular] make alternations of generations; they have 2 multicellular stages; 1n multicellular stage= gametophyte 1n gametes; 2n muliticellular stage= sporophyte makes spores plants: asexual reproduction includes reproduction through mitosis in 2 ways- rhizomes and corms animals: [asexual] babies grow from mitosis (either budding/fission or parthenogenesis).

Explain the effect of positive feedback of estradiol on LH release

promotes an LH surge, which starts ovulation

Explain the role of progesterone during the luteal phase

suppresses estrogen