Biology Practice Flashcards: Human Reproduction, Health, Microbes, and Biotechnology

A comprehensive set of vocabulary flashcards covering the biological concepts of human reproduction, reproductive health, microbes in human welfare, and the principles of biotechnology.

Gametogenesis

The process of formation of gametes, specifically sperms in males and ovum in females.

Insemination

The transfer of sperms into the female genital tract.

Fertilisation

The process of fusion of a sperm with an ovum leading to the formation of a diploid zygote.

Gestation

The period of embryonic development following implantation and preceding delivery.

Parturition

The process of delivery of the foetus, also known as childbirth.

Scrotum

A pouch situated outside the abdominal cavity that helps maintain the testes at a temperature $2-2.5^{\circ}C$ lower than normal internal body temperature, necessary for spermatogenesis.

Testicular lobules

The approximately $250$ compartments found in each testis.

Seminiferous tubules

Highly coiled tubules inside each testicular lobule where sperms are produced, lined by male germ cells (spermatogonia) and Sertoli cells.

Sertoli cells

Cells within the seminiferous tubules that provide nutrition to the male germ cells.

Leydig cells

Interstitial cells located outside the seminiferous tubules that synthesise and secrete testicular hormones called androgens.

Male sex accessory ducts

Ducts including the rete testis, vasa efferentia, epididymis, and vas deferens.

Male accessory glands

Glands consisting of paired seminal vesicles, a prostate, and paired bulbourethral glands whose secretions constitute seminal plasma.

Uterine wall layers

The three layers of tissue in the uterus: external thin membranous perimetrium, middle thick smooth muscle myometrium, and inner glandular endometrium.

Mammary alveoli

Clusters of cells within mammary lobes that secrete milk, which is stored in the lumens of the alveoli.

Primary spermatocytes

Spermatogonia that undergo the first meiotic division (reduction division) to form two equal, haploid secondary spermatocytes.

Spermiogenesis

The process by which spermatids are transformed into spermatozoa (sperms).

Spermiation

The release of sperms from the seminiferous tubules after their heads become embedded in the Sertoli cells.

Acrosome

A cap-like structure at the anterior portion of the sperm head filled with enzymes that help in the fertilisation of the ovum.

Oogenesis

The process of formation of a mature female gamete, which is initiated during the embryonic development stage.

Ovulation

The release of the secondary oocyte (ovum) from the ovary after the rupture of the Graafian follicle.

Menarche

The first menstruation, which begins at puberty.

Menopause

The cessation of menstrual cycles in human beings, occurring around the age of $50$ years.

LH Surge

The rapid secretion of LH leading to its maximum level during the mid-cycle (about $14^{th}$ day) which induces ovulation.

Corpus luteum

The structure formed by the remaining parts of the Graafian follicle after ovulation that secretes large amounts of progesterone.

Amniocentesis

A procedure using fetal cells and dissolved substances in amniotic fluid to test for genetic disorders such as Down syndrome, haemophilia, and sickle-cell anemia.

RCH programmes

Reproductive and Child Health Care programmes initiated in India to create awareness and provide facilities for building a reproductively healthy society.

Lactational amenorrhea

A natural method of contraception based on the absence of menstruation during the period of intense lactation following parturition.

IUDs

Intra Uterine Devices, such as the non-medicated Lippes loop, copper-releasing CuT, and hormone-releasing LNG-20, inserted into the uterus to prevent conception.

Vasectomy

A surgical sterilisation procedure for males involving the removal or tying of a small part of the vas deferens.

Tubectomy

A surgical sterilisation procedure for females involving the removal or tying of a small part of the fallopian tube.

MTP

Medical Termination of Pregnancy, or induced abortion, which is the intentional or voluntary termination of pregnancy before full term.

IVF

In vitro fertilisation, a process where fertilisation occurs outside the body in laboratory conditions, commonly known as the test tube baby programme.

ZIFT

Zygote intra fallopian transfer, where a zygote or early embryo with up to $8$ blastomeres is transferred into the fallopian tube.

LAB

Lactic Acid Bacteria, such as Lactobacillus, which grow in milk and convert it into curd by producing acids that coagulate milk proteins.

Streptokinase

An enzyme produced by the bacterium Streptococcus, used as a 'clot buster' for removing clots from the blood vessels of patients with myocardial infarction.

Cyclosporin A

An immunosuppressive agent used in organ-transplant patients, produced by the fungus Trichoderma polysporum.

Statins

Blood-cholesterol lowering agents produced by the yeast Monascus purpureus that competitively inhibit the enzyme responsible for cholesterol synthesis.

BOD

Biochemical Oxygen Demand, a measure of the organic matter in water based on the oxygen consumed by bacteria to oxidise it.

Activated sludge

The sediment formed during secondary sewage treatment consisting of bacterial flocs.

Methanogens

Anaerobic bacteria, such as Methanobacterium, that produce large amounts of methane along with $CO_2$ and $H_2$ from cellulosic material.

Bacillus thuringiensis (Bt)

A microbial biocontrol agent used to control butterfly caterpillars; its toxin genes have been introduced into plants like Bt-cotton.

Biofertilisers

Organisms that enrich the nutrient quality of soil, including bacteria like Rhizobium and fungi that form mycorrhiza.

Genetic engineering

Techniques used to alter the chemistry of genetic material (DNA and RNA) and introduce them into host organisms to change their phenotype.

Bioprocess engineering

The maintenance of sterile conditions in chemical engineering processes to grow desired microbes or eukaryotic cells in large quantities for products like vaccines and enzymes.

Restriction enzymes

Proteins known as 'molecular scissors' that cut DNA at specific nucleotide sequences, categorised as exonucleases or endonucleases.

Palindrome in DNA

A sequence of base pairs that reads the same on two strands when the orientation of reading ($5' \rightarrow 3'$) is kept the same.

Gel electrophoresis

A technique used to separate DNA fragments by forcing them to move toward the anode through an agarose gel matrix.

PCR

Polymerase Chain Reaction, a process involving three steps (denaturation, primer annealing, and extension) to amplify a specific segment of DNA.