Module 5 - Biology Heredity

• Haploid


  Containing one set of paired chromosomes
• Diploid


  Plant classification group where seeds are formed on flowers
• Gametophyte


  Plant classification group where seeds are formed on cones
• Sporophyte


  Cell division of germ cells that produces four non-identical haploid gametes
• Meiosis


  Cell division of Somatic cells that produces two identical new diploid cells
• Mitosis


  Gamete-forming haploid stage in a plant's life cycle
• Angiosperm


  Spore-forming diploid stage in a plant's life cycle
• Fertilisation


  1. Ovary releases an egg (ovulation)

  2. The released egg travels to the fallopian tube via the oviduct

  3. Sexual intercourse occurs and the male releases semen, which is comprised of sperm, directly into the vagina

  4. The sperm swim from the vagina, through the cervix and uterus into the oviduct/fallopian tube

  5. The sperm fuses with the egg to create a zygote (new organism)

  6. Zygote creates a strong membrane which prevents any other sperm fertilising the egg meaning that the remaining sperm will die out

  7. The zygote travels down the oviduct to the uterus where it is implanted
• Implantation


  1. Attachment of the fertilised egg to the lining of the uterus

  2. As an embryo form (looks human like), the amniotic sac, umbilical cord and placenta develop

  3. Amniotic sac contains the unborn baby and is filled with fluid

  4. Placenta provides the oxygen and nutrients that a baby needs to survive whilst removing carbon dioxide and other waste

  5. The umbilical cord is the connection between the amniotic sac and the placenta (enables the survival of the baby)

  6. From implantation to birth, this period is known as pregnancy

  7. Human pregnancy is about 9 months
• Oestrogen


  Caused by luteinising hormone (hormone which triggers ovulation) responsible for the development of female characteristics and stimulates the female body to release an egg. It also aids blood flow and enables the growth and development of vital organs (e.g., lungs and kidneys). It is later secreted in pregnancy to enable the production of progesterone.
• Progesterone


  Initially released by the ovaries and then later by the placenta. It stimulates the thickening of the uterine lining early in pregnancy. It gradually rises as pregnancy continues, this enables the placenta to keep working and keeps the uterine relaxed. It additionally helps the mother's immune system tolerate the growth of the child as it is seen as foreign in the body. It loosens the uterine muscles to prepare the body for birth. It stimulates the production of milk and allows the uterine muscles to contract allowing the body to go into labour and give birth.
• Menstrual Cycle


  1. Menstruation: Uterine (Uterus) bleeding, accompanied by shedding of the Endometrium

  2. Pre-ovulation: Endometrial repair begins; development of ovarian follicle; uterine gradually thickens

  3. Ovulation: Rupture of mature follicle, releasing egg

  4. Pre-menstruation: Secretion of watery mucus by glands of the Endometrium, cervix, uterine tubes; movement and breakdown of unfertilised egg; development of corpus luteum

  5. Deuteration of corpus luteum and Endometrium
• what are the hormones involved in menstrual cycle

  LH ( leutenising hormone)
• Gene Flow


  The movement of genes from one population to another, resulting in an exchange of genetic material
• Gene Flow


  The movement of genes from one population to another, introducing new genetic material
• Genetic Variation


  The extent of differences in the DNA sequences of individuals within a species or population
• Recombination


  The shuffling of genes during meiosis, resulting in new combinations of alleles
• Genetic Drift


  The random change in the frequency of a gene or a genetic variant in a population over time, resulting from the sampling error of a small population
• Bottleneck Effect


  A sudden reduction in population size, resulting in the loss of genetic variation
• External Fertilisation Advantages


  Allows for direct sperm-egg interaction, increases genetic diversity through random mating, and enhances evolutionary adaptations
• External Fertilisation Disadvantages


  Mainly sperm mortality, limited fertilization success, increased genetic abnormalities
• Internal Fertilisation Advantages


  Provides a safe environment, increases fertilization success, reduces genetic abnormalities
• Internal Fertilisation Disadvantages


  Limited genetic diversity, reduced adaptation to environmental changes, increased maternal investment
• Frog Fertilisation


  External fertilization: sperm released into water to fertilize eggs
• Fish Fertilisation


  External fertilization: sperm and eggs released into water to fertilize
• Horse Fertilisation


  Internal fertilization: sperm fertilizes eggs in reproductive tract
• Human Fertilisation


  Internal fertilization: sperm fertilizes eggs in reproductive tract
• Budding


  Process where a new individual develops from a small outgrowth or bud on the parent organism
• Binary Fission


  Type of cell division where one cell divides into two daughter cells with same genetic material
• Budding Advantages


  Faster reproduction, increased genetic diversity, evasion of predators, and regeneration
• Binary Fission Advantages


  High reproduction rate, error correction, increased cell numbers, and evolutionary adaptation
• Hydra Budding


  Budding occurs through formation of small outgrowth on parent's body, bud detaches and forms new individual
• Corals Budding


  Budding occurs through formation of small polyps, detach and develop into new coral colonies
• Bacteria Budding


  Budding occurs through binary fission, daughter cells genetically identical to parent
• Fungal Budding


  Budding occurs when a small outgrowth, a chlamydospore, develops from a parent cell, eventually detach and form a new individual
• Fungal Spores


  Spores contain genetic material, released to reproduce, and disperse through air, water, or insects
• Bacterial Binary Fission


  Bacteria reproduce by binary fission, dividing into two daughter cells with genetic material
• Asymmetric Fission


  One daughter cell receives more genetic material than the other
• Symmetric Fission


  Both daughter cells receive equal amounts of genetic material
• Protist Binary Fission


  Protists reproduce through binary fission, dividing into two daughter cells with genetic material