Reproduction Flashcards
(45 cards)
What does life cycle begin with?
- Life cycle begins with a single cell
- Growth and differentiation
Whats established during embryonic development?
Reproductive traits
What is asexual reproduction ideal environment?
Constant, stable environment
What are clones?
Buds from somatic tissue
Whats parthenogenesis?
- No male gamete required
- Ova and female reproductive system only
What are 5 elements of sexual reproduction?
- Sex determination
- Gametogenesis
- Mating
- Fertilization
- Development
What is sex determination? In mammals? Birds? Honeybees?
-Determination of sex by genotype.
-Mammals
XX= female; XY= male
-Birds and butterflies
ZW= female; ZZ= male
-Honeybee
Asexual or sexual
Sexual always produces female (diploid= 2 sex chromosomes)
Asexual always produces male through parthenogenesis (haploid= 1 sex chromosome)
Whats hermaphroditism?
Capacity to produce both eggs and sperm
What are simultaneous hermaphrodites? Serial hermaphrodites?
- Simultaneous hermaphrodites
- Has both functional male and female sexual organs at the same time. Self-fertilization often occurs.
- Serial hermaphrodites
- Change sex in response to environmental cues
- Protygynous- Female organs develop
- Protandrous- Male organs develop
What is TSD?
- Temperature-dependent sex determination
- Environmental temperature during a critical period of embryonic development that determines whether an egg develops as male or female
Whats gametogenesis?
Process in which cells undergo meiosis to form gametes
What’s oogenesis? When does it start in a females life?
- Production of an ovum.
- Starts when fetus is 8-20 weeks old
What is an ovary composed of?
-Ova-producing oogonia and surrounding somatic cells
Whats follicluogenesis? When does it occur?
- Some follicles stimulated to mature
- Prior to ovulation
How do vertebrate ooctyes grow?
Grow by accepting material from somatic follicle cells
What are 3 modes distinguished by fate of ova prior to and after fertilization? Define each.
*Ovipary
Producing young by means of eggs that are hatched after they have been laid by the parent.
*Vivipary
Development of the embryo. Producing living young from within the body.
*Ovovivipary
Producing young by means of eggs that are hatched within the body of the parent,
How does the angler fish reproduce?
Parasitic mating
The male fuses himself onto the flesh of the much larger female anglerfish.
All that’s left of the male is his reproductive organs, which the female Angler will use to fertilize her eggs
Whats spermatogenesis? When? Where?
- Production of sperm
- Continuous
- In the seminiferous tubules of the male testes
3 Seminiferous tubule cell types?
- Leydig cells- adjacent to the seminiferous tubules in the testicle. They produce testosterone in the presence of luteinizing hormone (LH).
- Spermatogenic cells- Cells that give rise to sperm
- Sertoli cells- Absorbing extra cytoplasm from newly created spermatozoa- helps in spermatogenesis by keeping cells healthy and nourished/
Whats the male sex hormone for sexual maturation? Location? Function?
Androgens
Testes
Promote hair growth, voice deepening and libido
What are 5 male sex hormones for spermatogenesis? Location? Function?
- GnRH- Hypothalamus
- Stimulates LH release, FSH synthesis and release - LH- Anterier pituitary
- Androgen synthesis and release - FSH- Anterior pituitary
- stimulates spermatogenesis - Androgens- Testes (Leydig cells)
- stimulates spermatogensis - Prostaglandins- Seminal vesicles
- Induce changes within uterus that affect sperm motility
What happens in sperm release? Where is the sperm stored?
- Spermatids become sperm
- Nearly mature spermatozoa (cannot swim) released into the lumen of the tubule
- Sperm stored in the epididymis where they mature further – gain capacity to swim
What happens during ejaculation? What is the sperm propelled down? How?
-During ejaculation, sperm propelled by cilia or smooth muscle contractions along the vas deferens which connect to the urethra
What glands is seminal fluid added to the sperm by during ejaculation?
Seminal vesicles- 60% of fluids; made of fructose
Prostate- produce seminal fluid
Bulbourethral gland-