Animal Reproduction: Asexual and Sexual Processes

Asexual Reproduction

Efficient reproduction without mating, limits genetic diversity.

Genetic Variability

Diversity in genetic makeup, crucial for adaptation.

Budding

New individuals grow from parent bodies via mitosis.

Regeneration

Replacement of lost tissues or limbs in organisms.

Fission

Splitting of an organism into two new individuals.

Parthenogenesis

Development of offspring from unfertilized eggs.

Gametes

Haploid cells formed during gametogenesis for reproduction.

Gametogenesis

Process of forming gametes in gonads.

Haploid

Cell with one set of chromosomes, e.g., gametes.

Diploid

Cell with two sets of chromosomes, e.g., zygote.

Meiosis

Cell division producing gametes with genetic diversity.

Crossing Over

Exchange of genetic material during meiosis.

Independent Assortment

Random distribution of chromosomes during gamete formation.

Testes

Male gonads producing motile sperm.

Ovaries

Female gonads producing nonmotile ova (eggs).

Fertilization

Union of sperm and egg forming a diploid zygote.

Sperm Recognition

Specific interaction ensuring correct fertilization.

Egg Activation

Metabolic activation of the egg post-fertilization.

Somatic Cells

Body cells distinct from germ cells.

Germ Cells

Cells that develop into gametes during reproduction.

Mating Behavior

Actions involving courtship and pairing for reproduction.

Environmental Change

Alterations in surroundings impacting species adaptation.

Sexual Reproduction

Involves union of haploid gametes, enhancing genetic diversity.

Aquatic Fertilization

Sperm and eggs released into water for reproduction.

Haploid

Cell with a single set of chromosomes.

Internal Fertilization

Sperm deposited directly into female reproductive tract.

Cumulus

Cells in a gelatinous matrix surrounding the egg.

Zona Pellucida

Protective layer beneath the cumulus of the egg.

Acrosomal Reaction

Sperm head reaction triggered by zona pellucida.

Acrosome

Membrane-enclosed structure containing enzymes on sperm.

Polyspermy

Fertilization by multiple sperm, usually lethal.

Sodium Influx

Na+ influx alters egg membrane charge.

External Fertilization

Gametes released into water for fertilization.

Spawning

Release of gametes into aquatic environments.

Gonads

Primary sex organs producing gametes.

Accessory Sex Organs

Additional genitalia components aiding reproduction.

External Genitalia

Visible reproductive structures, e.g., penis.

Copulation

Joining of male and female reproductive organs.

Spermatophores

Packets of sperm deposited in the environment.

Dioecious Species

Species with distinct male and female individuals.

Monoecious Species

Species with individuals producing both sperm and eggs.

Simultaneous Hermaphrodite

Individual producing both gametes at the same time.

Sequential Hermaphrodite

Individual changing sex during its life cycle.

Oviparous Animals

Lay eggs; embryos develop outside the body.

Viviparous Animals

Retain embryos inside the mother's body.

Embryo Development

Varies among mammals at birth stage.

Uterus

Holds embryo until birth in females.

Placenta

Facilitates nutrient and waste exchange with mother.

Ovoviviparity

Retaining fertilized eggs until hatching in some species.

Semen

Contains sperm and fluids supporting fertilization.

Testes

Produce sperm and testosterone, located in scrotum.

Spermatogenesis

Process of sperm production in seminiferous tubules.

Leydig Cells

Produce testosterone in the testes.

Sertoli Cells

Nourish developing sperm in seminiferous tubules.

Epididymis

Stores and matures sperm after production.

Vas Deferens

Connects epididymis to urethra for sperm transport.

Seminal Vesicles

Secrete seminal fluid components into vas deferens.

Prostate Gland

Produces alkaline fluid to enhance semen.

Bulbourethral Glands

Secrete lubrication for sperm movement during climax.

Penile Erection

Caused by blood vessel dilation from nitric oxide.

cGMP

Molecule causing blood vessel dilation in erection.

Emission

Movement of semen into urethra before ejaculation.

Ejaculation

Muscle contractions force semen out of penis.

GnRH

Hormone stimulating LH and FSH release at puberty.

LH

Luteinizing hormone increasing testosterone production.

FSH

Follicle-stimulating hormone aiding spermatogenesis.

Inhibin

Negative feedback on FSH production by Sertoli cells.

Orgasm

Intense pleasure accompanying emission and ejaculation.

Erectile Dysfunction

Condition treated by drugs inhibiting cGMP breakdown.

Ovary

Organ that releases eggs during ovulation.

Oviduct

Tube where fertilization occurs and eggs travel.

Fimbria

Finger-like projections guiding the egg to oviduct.

Cilia

Hair-like structures moving the egg toward uterus.

Uterus

Organ where fertilized egg develops into embryo.

Cervix

Narrow passage connecting uterus to vagina.

Vagina

Canal through which the baby exits during birth.

Fertilization

Fusion of sperm and egg nuclei forming zygote.

Zygote

Diploid cell resulting from sperm-egg fusion.

Blastocyst

Stage of development after zygote undergoes division.

Endometrium

Uterine lining where blastocyst implants.

Placenta

Organ formed from blastocyst interaction with endometrium.

Ovarian Cycle

Cycle producing eggs and hormones in females.

Uterine Cycle

Cycle preparing endometrium for potential implantation.

Menstruation

Sloughing off of endometrium if no implantation occurs.

Primary Oocytes

Immature eggs present in ovaries at birth.

Follicle

Structure containing a primary oocyte and surrounding cells.

Corpus Luteum

Endocrine gland formed from leftover follicle cells.

Estrogen

Hormone promoting development of female secondary characteristics.

Progesterone

Hormone maintaining endometrium for potential pregnancy.

GnRH

Hormone stimulating FSH and LH production at puberty.

FSH

Hormone stimulating follicle growth and estrogen production.

LH

Hormone triggering ovulation and corpus luteum formation.

Negative Feedback

Inhibition of hormone release to regulate reproductive cycles.

hCG

Hormone secreted by blastocyst after implantation.

Corpus Luteum

Produces estrogen and progesterone during early pregnancy.

Endometrium

Uterine lining maintained by estrogen and progesterone.

Pregnancy Testing

Detects hCG presence in urine or blood.

Placenta

Nourishes embryo and produces hormones during pregnancy.

Gonadotropins

Hormones that stimulate ovarian function, inhibited during pregnancy.

Birth Control Pills

Maintain high estrogen and progesterone levels to prevent ovulation.