Reproductive System Flashcards
(25 cards)
What is asexual reproduction?
Reproduction without fusion of gametes; includes budding, fragmentation, and parthenogenesis.
Give an example of asexual reproduction by fragmentation.
Sea slugs or planarians regenerating from body parts.
What is parthenogenesis?
Development of an embryo without fertilization, seen in aphids, water fleas, some bees, reptiles, and fish.
Why did some species evolve sexual reproduction?
To generate genetic variation for better adaptability to changing environments.
Name the 6 key needs of sexual reproduction.
Gamete-producing organs
Viable gamete release
Mating behavior/environment
Safe zone for embryo development
Birth
Parental care
What process produces gametes?
Meiosis
Where are sperm produced?
Seminiferous tubules in the testes
What hormones are secreted by Leydig cells?
Testosterone and INSL3
Why are testes external in many mammals?
For temperature regulation and to protect against intra-abdominal pressure (e.g., during galloping)
How long is the spermatogenesis cycle in humans?
~72 days
What is the fundamental reproductive unit of the ovary?
The follicle
What triggers follicle development and ovulation?
Pituitary gonadotropins (FSH & LH)
When are primordial follicles established?
During fetal life (5–16 weeks gestation)
What happens to most follicles?
They undergo atresia (apoptotic cell death)
What are the main ovarian hormones?
Estradiol (E2) and Progesterone (P4)
What are the main pituitary gonadotropins?
Follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
What are the two phases of the menstrual cycle?
Follicular phase and luteal phase
What is capacitation?
Changes in sperm in the female tract that enable fertilization
Where does fertilization typically occur?
In the oviduct
What forms after the fusion of male and female pronuclei?
A zygote
Name stages of early embryo development.
Zygote → 2-cell → 4-cell → morula → blastocyst
What is the difference between oviparous and viviparous animals?
Oviparous lay eggs; viviparous give birth to live young.
What is the difference between monotocous and polytocous species?
Monotocous have single births; polytocous have litters.
What process ends gestation?
Parturition (birth)
