Download Cell Reproduction

Cell Reproduction
Cell Cycle
Mitosis
Meiosis
Cell Cycle
• Interphase – the phase of a cell cycle in
which a cell grows to mature size and
carries out typical activities
– G1: Growth stage, cell performs typical
activities and grows to a mature size
– S: Synthesis stage, makes a copy of DNA
– G2: Growth twice, cell makes copies of the
organelles and doubles in size
Mitosis
• The process of dividing a cell’s nucleus to
make to identical nuclei
– Prophase: chromosomes in the DNA have
been copied
– Metaphase: nucleus disappears and paired
chromosomes line up in the center of cell
– Anaphase: pairs of chromosomes separate
and move to opposite sides of the cell
– Telophase: two nuclei form and the cell
divides into two identical daughter cells
Cytokinesis – division of the cytoplasm
Cancer
• Cancer is a physical condition in which a cell
grows without control, dividing too much
• Tumor – a ball of cancerous cells
– Benign tumor: grow in only one area of the body
– Malignant tumor: spreads throughout the body
• Metastasis – process of cancer cells
spreading to other body areas
Cancer
Meiosis
• Gametes, sex cells, perform the process
of meiosis, which is the division of sex
cells
• Male gametes are call sperm cells and
female gametes are call egg cells.
• Gametes are referred to as haploid cells;
one copy of each kind of chromosome
• Somatic cells, all other kinds of cells, are
referred to as diploid cells; two copies of
each kind of chromosome
Meiosis I
• Tetrad – a pair of homologous chromosomes
joined together
• Prophase I: The chromosomes in DNA have
been copied. Chromosomes are paired
• Metaphase I: Paired chromosomes line up
• Anaphase I: Paired chromosomes separate
and move to opposite sides of the cell
• Telophase I: The cell divides, resulting in
two cells with two copies of the same
chromosome
Meiosis I
Prophase I
Metaphase I
Anaphase I
Telophase I
Meiosis I
• Crossing over – the process of
homologous chromosomes in a tetrad
trading pieces of similar DNA
– Makes every organism unique
– Creates different chromosomes that are
passed to offspring
– Ex. Parents with blue eyes have children with
green eyes
Meiosis II
• Prophase II: Paired chromosomes line up
in each haploid daughter cell
• Metaphase II: Members of each pair line
up in the middle of the cell
• Anaphase II: Members of each pair move
to opposite sides of the cell
• Telophase II: The cells divide, resulting in
four haploid daughter cells with one copy
of each type of chromosome
Meiosis II
Prophase II
Metaphase II
and Anaphase
II
Telophase II
Male Reproductive System
• Testis – the male sex organ that produces
sperm cells
• Scrotum – the sac that holds the testes
• Penis – the male organ that delivers the
sperm to the female body
• Prostate gland – the structure that mixes
and stores semen that is ready to be
ejaculated
Male Reproductive System
• Vas deferens – the tubes that connect the
testes to the urethra
• Seminiferous tubules – the tissue in the
testes where sperm are produced
• Urethra – the tube that carries urine and
semen out of the body
• Testosterone – the male sex hormone
• Spermatogenesis – the process of making
sperm cells
Male Reproductive System
Urinary bladder
Vas deferens
Prostate gland
Penis
Urethra
Seminiferous
tubules
Scrotum
Testis
Female Reproductive System
• Ovary – the female organ that makes egg
cells (oocyte)
• Follicle – a ball of cells with a growing egg
cell found inside
• Fallopian tube – a tube through which
eggs pass from an ovary to the uterus
• Uterus – an organ in most female
mammals that holds and protects an
embryo
Female Reproductive System
• Vagina – tube-like canal in the female
body through which sperm enter
• Cervix – an opening that connects a
female’s uterus and vagina
• Oogenesis – the process of creating an
egg cell
• Estrogen – the female sex hormone
Female Reproductive System
Conception and Pregnancy
• Fertilization – sperm cell joins with an egg
cell in the Fallopian tube
• Conception – the joining of the sperm and
egg
• Pregnancy – the development of a fertilized
egg into a baby inside the female’s body
• Gestation time – the period of development
of a mammal from fertilization until birth
Conception and Pregnancy
• Zygote – fertilized egg that has undergone
mitosis
• Embryo – a fertilized egg up until week nine
of gestation
• Fetus – has all of the major structures found
in babies
• Umbilical cord – contains blood vessels that
provide the embryo with food and oxygen
• Placenta – tissue that connects the baby to
the mother’s food and oxygen supply