Life Processes – Reproduction (Chapter 3)

Vocabulary flashcards summarizing key terms and definitions related to human and plant reproduction, hormones, cell division, and modern reproductive technologies from Chapter 3 Life Processes – 2 lecture notes.

Asexual Reproduction

Mode of reproduction that occurs with somatic cells only, involves mitosis, and produces genetically identical offspring.

Sexual Reproduction

Reproduction that involves formation and fusion of gametes through meiosis, yielding genetically varied offspring.

Binary Fission

Type of asexual reproduction in which a unicellular parent divides into two equal daughter cells, e.g., Amoeba, Paramecium.

Multiple Fission

Amoeba’s asexual method where repeated nuclear divisions in a cyst produce many daughter cells (amoebulae).

Budding (Yeast)

Asexual process where a small outgrowth (bud) forms on parent yeast, receives a nucleus, and detaches as a new cell.

Fragmentation

Body of an organism (e.g., Spirogyra) breaks into pieces, each growing into a new individual.

Vegetative Propagation

Asexual reproduction in plants using roots, stems, leaves, or buds, e.g., potato eyes, Bryophyllum leaf buds.

Spore Formation

Asexual reproduction in fungi like Mucor where sporangia release spores that germinate into new colonies.

Mitosis

Somatic cell division producing two genetically identical diploid daughter cells.

Meiosis

Reductional cell division in germ cells producing four haploid gametes with half the chromosome number.

Gamete

Haploid reproductive cell (sperm or ovum) formed by meiosis.

Zygote

Diploid cell formed by fusion of male and female gametes during fertilization.

Ovulation

Release of a mature oocyte from the ovarian follicle under luteinizing hormone influence.

Menstrual Cycle

Cyclic changes (~28-30 days) in female reproductive system involving ovaries and uterus, leading to menstruation.

Follicle Stimulating Hormone (FSH)

Pituitary hormone that stimulates ovarian follicle growth and spermatogenesis.

Luteinizing Hormone (LH)

Pituitary hormone triggering ovulation and formation of corpus luteum; stimulates testosterone release in males.

Estrogen

Ovarian hormone that regenerates endometrium and promotes female secondary sexual characters.

Progesterone

Corpus luteum hormone that prepares and maintains the uterine lining for implantation.

Testosterone

Primary male sex hormone responsible for spermatogenesis and male secondary sexual characters.

Corpus Luteum

Yellow body formed from ruptured follicle; secretes progesterone (and estrogen).

Corpus Albicans

Degenerated corpus luteum when pregnancy does not occur.

Endometrium

Inner lining of uterus that thickens for implantation and is shed during menstruation.

Implantation

Embedding of the embryo into the uterine endometrium.

Parturition

Childbirth process initiated by uterine contractions under oxytocin influence.

Oxytocin

Pituitary hormone that stimulates uterine contractions and milk ejection.

Testis

Male organ producing sperm and testosterone.

X Chromosome

Sex chromosome present in both sexes; contributes to female offspring when paired XX.

Y Chromosome

Male-specific sex chromosome; its presence (XY) determines male sex in humans.

Pollination

Transfer of pollen grains from anther to stigma of a flower.

Double Fertilization

Process in flowering plants where one male gamete fuses with egg (zygote) and the other with polar nuclei (endosperm).

Androecium

Male floral whorl composed of stamens (anther + filament).

Gynoecium

Female floral whorl made of carpels (ovary, style, stigma).

Calyx

Outermost floral whorl; green sepals protecting the bud.

Corolla

Second floral whorl; colorful petals attracting pollinators.

Stamen

Male reproductive unit of flower consisting of anther and filament.

Carpel

Female reproductive unit of flower comprising ovary, style, and stigma.

Anther

Pollen-producing part of stamen containing pollen sacs (locules).

Ovary (Plant)

Basal part of carpel housing ovules; develops into fruit after fertilization.

Embryo Sac

Haploid female gametophyte inside ovule containing egg cell and polar nuclei.

Pollen Tube

Tube grown from pollen grain through style to deliver male gametes to embryo sac.

Spore

Haploid, usually unicellular reproductive unit capable of developing into a new organism without fusion.

Sporangium

Spore-producing structure in fungi and some plants.

Spermatogenesis

Process of sperm formation in seminiferous tubules of testis.

In Vitro Fertilization (IVF)

Technique where fertilization occurs outside the body in a lab, and embryo is transferred to uterus.

Surrogacy

Arrangement where a surrogate woman carries and delivers a pregnancy for another individual/couple.

Sperm Bank

Facility that collects, screens, and stores donated semen for assisted reproduction.

Condom

Barrier contraceptive device preventing sperm entry into female reproductive tract; also reduces STDs.

Intra-uterine Device (IUD)

Contraceptive device placed in uterus to prevent pregnancy.

Syphilis

Sexually transmitted bacterial disease caused by Treponema pallidum.

Gonorrhoea

Sexually transmitted infection caused by Neisseria gonorrhoeae, leading to painful urination and discharge.

Monozygotic Twins

Identical twins arising from a single fertilized egg that splits into two embryos.

Dizygotic Twins

Fraternal twins produced when two separate ova are fertilized by two different sperms.

Population Explosion

Rapid, excessive growth of human population in a short period.

Family Planning

Strategies (e.g., condoms, IUDs) adopted to control number and spacing of children.

Maintenance of Species

Continued survival of a species through reproduction preventing extinction.

Genetic Diversity

Variation in genetic composition among individuals resulting from sexual reproduction and meiosis.

Diploid

Cell having two sets of chromosomes (2n), typical of somatic cells.

Haploid

Cell possessing one set of chromosomes (n), typical of gametes.

Fission

General term for asexual reproduction where a parent cell splits to form new individuals.

Cyst (Amoeba)

Protective structure formed under adverse conditions where multiple fission occurs.

Pseudopodia

Temporary cytoplasmic projections in Amoeba used for movement and feeding; lost before cyst formation.

Embryo

Early developmental stage following zygote formation until fetal stage or seed maturation.

Implantation Site (Uterus)

Region in endometrium where embryo embeds and develops.

Placenta

Temporary organ connecting fetus and mother for nutrient and gas exchange.

Parturition Hormone

Oxytocin, which triggers labor contractions.

FSH in Males

Stimulates spermatogenesis in the seminiferous tubules.

LH in Males

Stimulates Leydig cells to secrete testosterone.

Test-tube Baby

Lay term for a child conceived through IVF technology.

Somatic Cell

Any body cell other than gametes; undergoes mitosis.

Germ Cell

Cell destined to form gametes; undergoes meiosis.

Chromosome

DNA-protein structure carrying genetic information, crucial during cell division.

Oxidative Energy Processes

Nutrition and respiration, which generate energy required for life processes.

Pollination Agents

Biotic or abiotic factors (wind, water, insects) that transfer pollen.