Insect Reproduction Strategies Quiz

Reproduction

• Reproduction is the production of offspring, either sexually or asexually.

Reproduction Strategies

• Asexual reproduction requires only one parent organism.
• Sexual reproduction requires two parent organisms (male and female). Male gametes are sperm and female gametes are ova (eggs). Fusion of these forms a zygote.

Mechanisms of Asexual Reproduction

• Many invertebrates reproduce asexually by fission (splitting of a parent into two or more individuals).
• Other common asexual reproductive mechanisms in invertebrates include budding (new individuals grow as outgrowths from the parent) and fragmentation (a parent breaks into several pieces, each developing into a new individual).
• Parthenogenesis also occurs in invertebrates (an egg develops into a new individual without fertilization).

Sexual Reproduction

• Two Parents: Each parent has specific reproductive organs.
• Male reproductive organs: Testes produce sperm.
• Female reproductive organs: Ovaries produce ova (eggs).

Reproduction Strategies - Types

• Internal vs External Fertilization: Sperm deposited in or near female's reproductive tract; or in the external environment.
• Semelparity: Single reproductive episode before death (octopus, mayfly, salmon).
• Iteroparity: Multiple reproductive episodes over lifespan (most animals).

External vs Internal Fertilization

• External fertilization: Eggs released by female, fertilized by sperm outside the body.
• Internal fertilization: Sperm deposited in or near the female reproductive tract; fertilization occurs within the tract.

Reproductive Cycles and Patterns

• Many animals have cycles in reproductive activity, often linked to changing seasons.
• These cycles are controlled by hormones and environmental cues.

Hermaphroditism & Alternation of Sexes

• Simultaneous hermaphroditism: Both male and female gametes are present in the same organism (self-fertilization possible); Bluehead wrasse female first.
• Sequential hermaphroditism: Change sex during their lives. Protandrous: male first.

Liver Fluke (Sexual and Asexual Reproduction)

• Liver flukes have both sexual and asexual reproductive cycles.
• They have separate male and female reproductive organs.

Female Gametes - Reproduction Types

• Oviparity: Eggs laid outside the mother's body.
• Ovoviviparity: Eggs develop inside the mother, nutrients stored in the egg; hatch in the mother's uterus.
• Viviparity: No eggs; embryo develops inside the mother; all mammals except monotremes.

Insects

• Insects have separate sexes with complex reproductive systems.
• Detailed descriptions of male and female reproductive structures in insects.

Mammalian Reproduction: Males

• Male gonads (testes) consist of coiled tubes (seminiferous tubules) surrounded by connective tissue.
• Sperm production occurs in the testes.
• Sperm travels through the epididymis, vas deferens, ejaculatory duct, and urethra.
• Accessory glands produce fluids that become semen, including fructose and other energy sources, as well as buffers. The pair of seminal vesicles contribute around 60% of seminal fluid. The prostate gland and bulbourethral glands also contribute to seminal fluid.

Spermatogenesis

• Detailed process describing the development of sperm through mitosis and meiosis.

Accessory Glands

• Detailed description of male accessory glands (prostate, seminal vesicles, bulbourethral glands) and their roles.

Female Reproductive Organs: Ovary

• Ovaries are located in the abdominal cavity.
• Each ovary contains follicles, with an egg cell surrounded by follicle cells.
• Ovulation releases the egg cell.
• Remaining follicle tissue forms the corpus luteum, which secretes hormones.

Oogenesis

• Process of egg cell development from immature egg cells (oogonia).
• Oogonia undergo mitosis and then meiosis.

Oogenesis

• More detailed description of the steps in oogenesis and the formation of the oocyte.
• Primary oocytes begin meiosis in fetal life, but complete meiosis only if fertilization occurs.
• There are two divisions of meiosis.

Ovaries. Hormones

• The ovaries produce hormones like estrogen and progesterone, with detailed roles in ovulation, pregnancy, and related processes.

Oviducts and Uterus

• Egg released into abdominal cavity, near oviduct(fallopian tube).
• Cilia convey egg to the uterus.

Ovarian Cycle

• The ovarian cycle has phases (follicular and luteal) relating to follicle development, ovulation, and corpus luteum formation, and includes hormone levels (e.g., GnRH, FSH, LH).

Luteal Phase

• Description of the luteal phase and corpus luteum formation, function (production/secretion of progesterone and estrogen).
• Functions of progesterone and estrogen in relation to the uterine wall (endometrium).

Fertilization

• Acrosome reaction activates the egg.
• Sperm contacts egg plasma membrane, calcium released from internal organelles that triggers changes in the egg membrane to prevent other sperm from fertilizing the same egg.

Gamete Production. Meiosis

• Detailed comparison/overview of oogenesis and spermatogenesis, including the phases of meiosis.

Revision Questions

• List of suggested revision questions based on the topics covered in the slides.