Slide 1

Reproduction in Organisms

• The process by which new individuals of the same species are produced
• Essential for the survival and continuity of a species

Slide 2

Types of Reproduction

• Asexual reproduction

  • Single parent is involved
  • Offspring are genetically identical to the parent
  • Examples: binary fission, budding, vegetative propagation

• Sexual reproduction

  • Involves fusion of gametes from two parents
  • Offspring inherit traits from both parents
  • Examples: fertilization, meiosis

Slide 3

Asexual Reproduction

• Binary fission

  • Division of a single organism into two identical daughter organisms
  • Example: bacterial cells

• Budding

  • Outgrowth of a part of the parent organism that grows and detaches to form a new individual
  • Example: hydra, yeast

• Vegetative propagation

  • New plants are produced from vegetative parts of the parent plant, like roots, stems, or leaves
  • Example: runners in strawberry plants

Slide 4

Sexual Reproduction

• Fertilization

  • Fusion of male and female gametes to form a zygote
  • Gametes contribute genetic material to the offspring
  • Example: human reproduction

• Meiosis

  • Process of cell division that forms gametes (sperm and eggs)
  • Reduces the chromosome number by half
  • Important for maintaining the correct number of chromosomes in a species

Slide 5

Life Span of Different Organisms

• Organisms can be classified based on their life span:
  • Annual: complete life cycle in one year
  • Biennial: complete life cycle in two years
  • Perennial: live for many years
  • Example: oak tree (perennial), dandelion (annual)

Slide 6

Annual Life Span

• Complete life cycle in one year
• Example: marigold plant
• Seeds germinate, grow, produce flowers, and produce new seeds within a year

Slide 7

Biennial Life Span

• Complete life cycle in two years
• Example: carrot plant
• In the first year, the plant produces leaves and stores energy in the root
• In the second year, the stored energy is used for flowering, seed production, and then the plant dies

Slide 8

Perennial Life Span

• Live for many years
• Example: oak tree
• Trees continue to grow and reproduce for several years, sometimes even for hundreds of years

Slide 9

Factors Affecting Life Span

• Internal factors:

  • Genetic makeup of the organism
  • Presence of specific genes that control aging processes

• External factors:

  • Environmental conditions, such as temperature and availability of resources
  • Predation and the ability to avoid or withstand threats

Slide 10

Adaptations for Long Life Span

• Long-lived organisms exhibit certain adaptations:
  • Slow growth rate
  • Efficient repair mechanisms for DNA and cellular components
  • Ability to reproduce at a later age
  • High resistance to environmental stress

====

Slide 11

Factors Affecting Reproduction

• Availability of resources
• Temperature and climate conditions
• Presence of suitable mates
• Hormonal regulation
• Genetic factors

Slide 12

Human Reproduction

• Human reproductive system consists of male and female reproductive organs

• Male reproductive system:

  • Testes produce sperm
  • Sperm is ejaculated through the penis

• Female reproductive system:

  • Ovaries produce eggs
  • Eggs are released during ovulation and travel through the fallopian tubes to the uterus

Slide 13

Menstrual Cycle

• Monthly cycle in females during which the uterus prepares for pregnancy
• Divided into four phases:
  • Menstrual phase: shedding of the uterine lining
  • Proliferative phase: growth of a new uterine lining
  • Ovulation phase: release of a mature egg from the ovary
  • Luteal phase: preparation of the uterus for implantation

Slide 14

Fertilization and Pregnancy

• Fertilization occurs when a sperm penetrates and fuses with an egg
• The resulting zygote implants in the uterus and pregnancy begins
• Development of the embryo and fetus occurs during pregnancy
• Hormonal changes and physiological adaptations support the growing fetus

Slide 15

Hormonal Control of Reproduction

• Gonadotropins: hormones that regulate reproductive functions
• Follicle-stimulating hormone (FSH): stimulates development of ovarian follicles in females and sperm production in males
• Luteinizing hormone (LH): triggers ovulation and formation of the corpus luteum in females, and stimulates testosterone production in males

Slide 16

Control of Menstrual Cycle

• Regulation of menstrual cycle involves a feedback loop between the hypothalamus, pituitary gland, and ovaries
• Hypothalamus releases gonadotropin-releasing hormone (GnRH)
• GnRH stimulates the pituitary gland to release FSH and LH
• FSH and LH control the development of follicles and the production of estrogen and progesterone

Slide 17

Methods of Contraception

• Contraceptive methods aim to prevent unwanted pregnancies
• Barrier methods: condoms, diaphragms
• Hormonal methods: birth control pills, patch, vaginal ring
• Intrauterine devices (IUDs)
• Sterilization: tubal ligation or vasectomy
• Natural methods: tracking fertility and avoiding intercourse during fertile periods

Slide 18

Infertility and Assisted Reproductive Technologies

• Infertility: inability to conceive after one year of unprotected intercourse
• Assisted reproductive technologies (ART):
  • In vitro fertilization (IVF): fertilization of eggs in a lab dish and transfer of embryos to the uterus
  • Intrauterine insemination (IUI): placement of sperm directly into the uterus
  • Surrogacy: another woman carries and gives birth to a child for a couple

Slide 19

Reproductive Health and STIs

• Reproductive health refers to the overall well-being and functioning of the reproductive system
• Sexually transmitted infections (STIs) are infections transmitted through sexual contact
• Examples of STIs: HIV/AIDS, gonorrhea, chlamydia, syphilis
• Importance of safe sexual practices and regular check-ups for early detection and treatment

Slide 20

Summary

• Reproduction is essential for the survival and continuity of a species
• Different organisms have different life spans, which can be annual, biennial, or perennial
• Reproductive processes can be asexual or sexual
• Human reproduction involves the male and female reproductive systems
• Hormonal control and menstrual cycle play a crucial role in reproductive processes

Slide 21

Mitosis: Cell Division for Growth and Repair

• Mitosis is a type of cell division that occurs in somatic cells
• It is responsible for growth, repair, and maintenance of the body
• Steps of mitosis:
  1. Interphase
  2. Prophase
  3. Metaphase
  4. Anaphase
  5. Telophase
  6. Cytokinesis

Slide 22

Meiosis: Cell Division for Gamete Formation

• Meiosis is a type of cell division that occurs in reproductive cells (sperm and egg)
• It is responsible for the formation of gametes and genetic diversity
• Steps of meiosis:
  1. Interphase (preceding meiosis I)
  2. Prophase I
  3. Metaphase I
  4. Anaphase I
  5. Telophase I and cytokinesis
  6. Prophase II
  7. Metaphase II
  8. Anaphase II
  9. Telophase II and cytokinesis

Slide 23

Difference Between Mitosis and Meiosis

• Mitosis:

  • Occurs in somatic cells
  • Produces two identical daughter cells
  • Maintains the same chromosome number as the parent cell

• Meiosis:

  • Occurs in reproductive cells
  • Produces four non-identical daughter cells
  • Reduces the chromosome number by half

Slide 24

Importance of Genetic Diversity

• Genetic diversity is crucial for the survival and evolution of populations
• Allows for adaptation to changing environments
• Increases the chances of producing individuals with advantageous traits
• Provides a source of variation for natural selection to act upon

Slide 25

Variation and Natural Selection

• Variations occur in populations due to genetic diversity and mutations
• Natural selection acts upon these variations to favor individuals with advantageous traits
• Individuals with advantageous traits are more likely to survive and reproduce
• Over time, the frequency of advantageous traits increases in the population

Slide 26

Importance of Sexual Reproduction

• Sexual reproduction contributes to genetic diversity
• Increases the chances of survival in changing environments
• Enables the repair of damaged DNA through recombination
• Provides opportunities for evolution and adaptation

Slide 27

Role of Hormones in Reproduction

• Hormones play a crucial role in regulating reproductive processes
• Examples of reproductive hormones:
  • Follicle-stimulating hormone (FSH)
  • Luteinizing hormone (LH)
  • Estrogen and progesterone
  • Testosterone

Slide 28

Environmental Factors Affecting Reproduction

• Environmental factors can affect reproductive success in organisms
• Examples of environmental factors:
  • Temperature
  • Light availability
  • Nutrient availability
  • Availability of water

Slide 29

Reproductive Strategies in Plants

• Plants have various reproductive strategies to ensure successful reproduction
• Examples of plant reproductive strategies:
  • Wind pollination: pollen is carried by wind to reach female reproductive structures
  • Insect pollination: flowers attract and rely on insects for pollination
  • Self-pollination: pollen from the same flower fertilizes the ovules
  • Cross-pollination: pollen from one flower fertilizes the ovules of another flower

Slide 30

Reproductive Strategies in Animals

• Animals have different reproductive strategies based on their characteristics and environments
• Examples of animal reproductive strategies:
  • Courtship behaviors: display of desirable traits to attract mates
  • Mating systems: monogamy, polygamy, promiscuity
  • Parental care: protection and care provided by parents to offspring
  • Migratory patterns: movement to specific areas for mating and reproduction