Unit 9: Reproduction and Development

Unit 9: Reproduction and Development How are humans made?

A. Sexual Reproduction ________________________ offspring are a ____________ of parental genes 1. Advantages for Sexual Reproduction - _________ allows for adaptation to new environments - ______________ - _________________________

2. Meiosis and Gamete Formation - __________________ - Reduction Division - _________ - in humans this means the cell goes from ___ to ____ chromosomes a) Definitions: - _________ = process of cell division to make _______ cells and _____ cell (___________) - ________= 2n  the cell has two sets of chromosomes in humans the diploid number is 46 23 chromosomes from _______ and 23 chromosomes from ______ - _________________ = n  the cell has one set of chromosomes ______________________ are haploid  they only have 23 chromosomes

b) Process of Meiosis - meiosis only happens in ________ = _____________ male gonad = ________ female gonad = _______ - meiosis produces sex cells (gametes) which have half the number of chromosomes as compared to normal body cells - meiosis involves the cell dividing ________ 1) DNA Replication DNA in the nucleus copies - 46 chromosomes becomes 92 Cells – Chromosomes - DNA

2) Nucleus Disappears and Chromosomes Pair Together - ________________________ = the processes by which homologous chromosomes pair together and switch genes - _______________________ = similar chromosomes of the same size and shape; they carry to same kind of genes but may have different forms of the genes on them

- Synapsis and Crossing over increase the _____________ in offspring  it is one of the reason why you and your siblings do not look exactly alike - In crossing over, __________ of homologous chromosomes switch chromosomes and rearrange genes

3) Cells and Chromosomes Separate (2x) - Cell divides the chromosomes cell material twice - Makes ___________________ - Each daughter cell has 23 chromosomes Why would you make cells with half the number of chromosomes?

4) Meiosis in Males and Females Males: - make 4 sperm cells - meiosis happens all the time Females: - make ___ viable egg cell and 3 polar bodies - meiosis happens once a month

3. Fertilization - ________________________________ - combination of male and female gametes - n + n = 2n  23 + 23 = 46 – combining chromosomes of the parents - formation of a _________ = single cell that will become the baby sperm egg zygote

4. Human Reproduction a) Male Reproductive System 1) _________ - make and store sperm - Produce the hormone ___________________ - Scrotum - saclike pouch which houses the testes for proper sperm production the scrotum is __________ celsius below normal body temperature - Seminiferous tubules - carries/stores sperm from the testes 2) ___________ - temporary storage organ for sperm at the beginning of the Vas Deferens 3) _______________ - tube which carries the sperm past 3 lubricating glands - _____________ - removal or tie up of the Vas Deferens Stops sperm from being released from the body

4) Cowpers gland, Seminal Vesicle, Prostate Gland – - 3 lubricating glands - prostate produces an alkaline fluid which neutralizes the urine in the urethra - ________________ kills many over 70 males - treated with radiation and estrogen 5) _________ - tube through the penis 6) ________ - releases the semen inside the female - ___________ - liquid loaded with sperm - ____________ - the release of semen

b) Female Reproductive System - functional from puberty until menopause 1) _____________ – produce ovum = egg cells - Usually only one egg is released at a time 2) _____________________ - muscular contractions of the oviduct and beating of its cilia draw ovum into the oviduct - Normally fertilization and initial cleavage occurs in fallopian tubes 3) _____________ - spongy bed in which the zygote will become implanted and develop - embryonic development occurs here 4) _________ - narrow neck of the uterus - Cancer of the cervix is common  ____________ 5) ____________ – birth canal and opening to the outside of the body - site where sperm are deposited

6) Menstrual Cycle - hormone controlled process by which the ____________ and is released; it prepares the body for _____________ Stages: 1. ___________________ (10-14 days) - production of ova occurs in tiny cavities in the ovary called follicles - enlarging follicle produces ___________ which causes the uterus to get ready for embryo implantation (thickens its lining)

2. ___________________ (1 day) - follicle enlarges & ruptures ovary wall - egg is __________ to the oviduct 3. ___________________ (10 -14 days) - yellow tissue fills the follicle after ovulation - called the corpus luteum "yellow body" - secretes _____________ which readies the uterus for pregnancy 4. ___________________ (3-5 days) - periodic shedding of the thickened lining of the uterus which _____________________________

5. Human Development a) Fertilization  sperm deposited in the vagina and swim up the uterus to the Fallopian tubes. _________________ the egg _____________________ _____________________

b) Implantation  as the fertilized egg travels down the Fallopian tubes it goes through _________________ upon reaching the uterus the egg fastens itself to the uterine lining and begins pregnancy ectopic pregnancy  __________  ________  _________

c) Differentiation – Cell Specialization - Growth A – _________________ – site where mother and fetus exchange nutrients, wastes, O2, CO2 – blood __________ cross between mother and fetus B – _________________ – rope like tube that carries the nutrients and wastes to and from the fetus C – ___________ D – __________________ – surrounded by the chorion (membrane) helps protect the fetus and keep it stable

d) Fetal Nourishment Substances in the mother’s blood pass to the fetus _______________________ _________________________ Viruses e) Birth ______________ = length of pregnancy – 40 weeks (9 mon.) ______________ = muscular contractions of the uterus premature birth __________________ f) Growth  Puberty  Growth/Maintain  Death

Unit 9: Reproduction and Development