Reproductive System Flashcards by Tea Wade

What are the functions of the reproductive system?

Secretion of sex hormones
Production of gametes
Production of offspring

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How many pairs of chromosomes do humans have?

23, for a total of 46

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How many sets of chromosomes does a somatic cell have (and by the way what is a somatic cell?)

Two: 1 maternal, 1 paternal aka diploid (2n)
A somatic cell is any cell except gametes

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How many chromosomes do gametes have?

23, they are haploid (n)

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True or False: Gametes in a pair are identical

False. They are equivalent, they code for the same characteristics but one is maternal one is paternal

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What is the term for the fusion of a sperm cell and egg cell?

Fertilization is the process
Zygote is the cell

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What kind of cell is a zygote?

Diploid (2n)

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What is the purpose of meiosis I?

To reduce the number of original chromosomes in half to prepare for fusion

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What creates a unique set of chromosomes for each gamete?

Recombination aka Scrambling

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True or false. Gametes do not go through Interphase prior to meiosis

False. They do

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What happens in Prophase I of meiosis I?

Duplicates centriole pairs pair up forming tetrads

Crossing Over occurs: homologous chromosomes exchange equivalent segments

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What does crossing over mean? When/How does it occur and what does it create?

Homologous chromosomes exchange equivalent segments

Occurs between non-sister chromatids during Prophase I

Creates a new chromosome that has some maternal and some paternal parts

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What happens during Metaphase I?

Homologous chromosomes align in the center of the cell by miotic spindles

They are pulled apart into two separate cells

Independent Assortment - the side each chromosome lines up on is independent of other pairs

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What happens during Anaphase I?

Homologous chromosomes are separated and move to opposite poles

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What happens during Telophase I?

Two haploid (n) cells are formed

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What happens during Telophase II?

Cytokinesis occurs and a total of 4 cells containing gametes (n) are made

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What is the difference between the purpose of mitosis versus the purpose of meiosis?

Mitosis - Cell duplication to increase cell numbers. Makes sure cells stay the same.

Meiosis - Gamete production, produces genetic variation

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When does synapsis occur? What is synapsis?

Prophase I of Meiosis. This is the process where two homologous chromosomes line up, allowing for crossing over

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What are the 3 factors contributing to Genetic Recombination?

Crossing Over
Independent Assortment
Random Fertilization

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How many possible genetic combinations are possible before crossing over?

n^23 means 8 million combos in each gamete

8mil x 8mil = 64 trillion possible combinations

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What is gametogenesis?

The production of gametes. Begins in embryonic glands while in utero (amniotic life)

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Where foes spermatogenesis take place?

In the seminiferous tubules in the testis, within sustentacular cells aka Sertori cells

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What is the difference between spermatogenesis and spermiogenesis?

Spermatogenesis - Process if sperm cell production

Spermiogenesis - Spermatid maturation

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When does spermatogenesis start?

Puberty, continues throughout life

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What is the function of spermatogonia?

Goes through mitosis on the basal lamina at the blood-testicular barrier. For every one that goes through meiosis one remains behind to duplicate

What is important about the blood-testicular barrier?

Sperm cells are considered foreign by the body. If they crossed the barrier the immune system would develop antibodies for them

What are secondary spermatocytes?

Tetrad-containing cells (4 haploids not 2 diploids)

What happens in spermiogenesis?

Spermatids change shape, losing most of the cytoplasm and organelles

What are the hormonal effects of GnRH during spermiogenesis? What are the negative feedback loops?

GnRH > FSH > Sertoli cells > ABP increases spermatogenic cells' ability to bind to testosterone GnRH > LH > Leydig cells (aka interstitial cells) > testosterone production FSH produces inhibin, which decreases FSH secretion high testosterone levels decreases LH and GnRH secretion

What are the accessory male sex glands and their contribution to semen?

Seminal Vessicles - Left and Right, posterior base of bladder, 60% of volume. Rich in fructose Prostate Gland - Base of bladder, 30% of volume, Alkaline solution to protect sperm from acidic environment of the vagina Bulbourethral glands - beneath prostate on either side of membranal urethra. Alkaline fluid to neutralize urethra

What is semen?

A transport medium that protects and activates sperm

What do prostaglandins do?

Decrease cervical mucous viscosity and stimulates reverse peristalsis in the uterus

How much semen is ejaculated versus how much sperm?

2-5ml Contains 20-150 million sperm

What are the anatomical characteristics of the penis?

Contains a urethra and 3 cylindrical bodies of erectile tissue The corpus spongiosum expands to keep urethra open The corpora cavernosa keeps the penis erect

What is the difference between the two phases of male sexual response?

Erection - Enlargement and stiffening of erectile tissue with blood. Vasodilation of corpus cavernosa is caused by PSNS Ejaculation - Propulsion of semen by SNS

What are the two parts of ejaculation?

Emission - ducts and accessory organs rapidly contracting, bladder sphincter constricts Expulsion - Muscles at the base of the penis undergo rapid contractions

What happens in utero concerning oogenesis?

All oogonia complete mitosis and become primary oocytes, they begin meiosis but arrest at prophase I

How many oocytes complete meiosis I?

About 400/250,000 primaries present at puberty

What is the primordial follicle?

A layer of simple squamous cells surrounding primary oocytes

What happens during puberty concerning oogenesis?

A primordial follicle becomes a primary follicle (cuboidal cells), which enlarges when antrum expands with fluid to become a Graafian follicle (these cells will become corpus luteum after expulsion of secondary oocytes

How is a secondary oocyte made?

A primary oocyte is activates and completes meiosis I but its unequal distribution of cytoplasm causes production of a secondary oocyte and a first polar body

True or false. All secondary oocytes go through meiosis ii

False. They only complete meiosis II if they are fertilized, otherwise arrest at metaphase II and are ovulated

What happens when an ovulated secondary oocyte is fertilized?

A sperm cell merges with it and it completes meiosis II, yielding a secondary polar body and one large ovum

How many genomes are in a daughter cell?

How many chromatids are in each chromosome?

What has to happen to chromosomes before cell division?

Replication

How many gametes are in a cell at the end of each metaphase?

Metaphase I: 1 Metaphase II: 1

How many chromatids per chromosome in a cell during each metaphase?

MetPhase I: 4 Metaphase II: 2

How many chromatids per chromosome in a finished gamete? How many genomes?

How many types of gametes result from a 2n cell with X chromomoes?

2n to the n/2 power ie 4=2 squared = 4, 6 = 2 cubed = 8, 46 = 2 to the 23rd = 8 trillion

How many chromosomes would a human gamete have that resulted from meiosis with non-disjunction of one of the chromosome pairs?

22 or 24

What percentage of female ova will have X chromosomes?

100%

What percent of male sperm will have Y chromosomes?

50%. 50% will have X

If neurons can't divide, what type of cells produce brain tumors?

Glial cells

What term refers to all the gene alleles one has?

Genotype

What terms refers to all expressed alleles?

Phenotype

What are different versions of the same gene?

Alleles

What kind of chromosome contains alleles, with one gene on each chromosome in the pair?

Homologous

In order for an individual to express a recessive trait, what must be true about that individual?

They must have a homozygous chromosome with two recessive alleles

When does chiasmata (crossing over) occur?

Metaphase I and prophase I

What kind if genetic variation produces the uniqueness seen by the combination of a particular female and particular make gamete?

Random fertilization

What is a permanent transmissible change to the DNA coding sequence caused by environmental factors?

Mutation

What kind of genetic variation causes various combinations of homologous chromosomes from paternal and maternal lineage within a haploid cell?

Independent Assortment

What kind of inheritance most often results in a recessive trait, expressed more often i. males than in females?

Sex-Linked Recessive Inheritance

What kind of inheritance results in continuous phenotype variations between two extremes (ex. skin color)

Polygenic Inheritance

Blood type is the result of what kind of inheritance?

Multiple Allele Inheritance

Sickle cell anemia is an example of this kind of inheritance, where heterozygote had an intermediate between a homozygous dominant and a homozygous recessive?

Dominant-Recessive

What kind of inheritance is expressed only in the absence of a dominant gene, ig albinism?

Incomplete Dominance

What is an autosomal codominant allele?

Neither gene is dominant over the other and both are expressed

What two events happen during Prophase I?

Maternal and paternal DNA get mixed Nuclear envelope starts to break down

What pituitary hormone stimulates interstitial cells to make testosterone?

What hormone affects sustentacular cells to make inhibin and anti-Mullerian hormone?

FSH

What is ABP important for?

Increasing spermatogenic cells' ability to bind to testosterone

At what stage of meiosis do chromosomes align in the spindle equator in homologous pairs?

Metaphase

Primary oocytes are haploid or diploid?

Diploid

Secondary oocytes are haploid or diploid?

Haploid

Follicles rely on a steady supply of what hormone to develop?

Estrogen

Developing follicles produce what hormone?

Estrogen

What hormone exerts a negative feedback loop on LH production in oogenesis?

Inhibin

When estrogen levels reach a certain concentration it exerts a positive feedback on LH production, causing what?

An LH surge, followed by ovulation

What cells directly surround an oocyte in the secondary and vesticular follicles?

Thecal cells

What is the the remnant of the vesticular follicle after ovulation called? What foes it secrete?

The corpus luteum; progesterone

What hormone increases during the follicular (proliferative) phase?

Estrogen?

What happens during ovulation?

A secondary oocyte is expelled from the ovary where it is swept by fimbriae into the Fallopian tubes to be implanted in the uterine wall

When are ovarian hormones at their lowest?

The beginning of the menstrual phase, this is what triggers menstruation

What causes embryonic female ducts to disappear in a male embryo?

Anti-Mullerian hormone

What is the female copulatory organ?

Vagina

What is the vestibule?

The recess containing the opening of the vagina and uterus

What secretes mucus to lubricate the vaginal opening?

The greater vestibular gland

What moves oocytes or a fertilized ovum toward the uterus?

Uterine tube

What is the process of developing haploid sperm?

Spermatogenesis

What is the process by which sperm grow and develop?

Spermiogenesis

What stores sperm and moves it to the ductus deferens?

Epididymis

What transports semen out of the penis?

The utethra

What gland secretes an alkaline substance with anticoagulants?

Prostate gland

What stores sperm and moves it to the ejaculatory duct?

Ductus deferens

The absence/presence of what protein/gene causes sec determination?

SRY, on the Y chromosome

What are the bipotential tissues, what do they become?

Genital tubercle> gland penis/clitoris Urethral groove/fols > shaft of penis/labia minora Labioscrotal fold > shaft of penis & Scrotum/labia majora Gonad cortex> ---/Ovaries Gonad Medula > Testes/---

When is the functional zone of the endometrium restored?

The proliferarice phase of menses

The process of spermiogenesis produces what?

Soermatozoa

True or false: Semen contains prostaglandins, seminal fluid, fibrinogen, and spermatogonia.

False. Spermatozoa, not spermatogonia

What form if sexual differentiation results in short stature, a broad cheat, webbed neck, CV/kidney disorders, and female genetalia?

Turner's Syndrome

What form of sexual differentiation results in tall stature. female contours, breast development, male genetalia, and infertility?

Klenifelter's

Both male and female genetalia are present in what sexual abnormality?

True hermpahoditism

In what sexual differentiation do the gonads match the chromosomal sex but external genetalia are the opposite?

Psuedohermamphroditism

During what phase of menstruation is progesterone dominant?

Secretory phase

During what phase of menstruation does cervical mucus get thinner?

Proliferative phase

Are all of the following statements true? -Oogenesis begins before birth -Ova develop from stem cells called oogonia -By birth females have already lost about 80% of embryos

Yes

A rise in blood levels of FSH at the beginning of the ovarian cycle is responsible for what?

Follicle maturation

How does ejaculation happen?

Sympathetic stimulation causes peristaltic contractions of the the ampulla and contractions of the bulbospongiosus muscle

A primary spermatid matures into how many spermatids?

4, each containing 23 chromosomes