Contemporary Issues in Biology Exam 1 Study Guide

Vocabulary flashcards covering key biological concepts, definitions, statistics, and processes from Lectures 1 through 8.

Pseudoscience

Ideas presented as scientific without using the scientific method, which can mislead the public (e.g., snake oil, tobacco ads).

Peer Review

The gold standard for scientific credibility, in which less than $9\%$ of submissions pass in top journals.

Scientific Trust

A standard of trust that requires expertise, evidence, transparency, and a willingness to acknowledge uncertainty.

Male Reproductive Pathway

The route where sperm are produced in the testes, stored in the epididymis, travel through the vas deferens, and exit through the urethra.

Testosterone Regulation

A negative feedback loop involving the pituitary gland where high testosterone levels signal the pituitary to slow production.

PSA Test

A screening test for prostate cancer that detects cancer early but is controversial due to non-cancer causes of elevation and a small absolute risk reduction from $0.6\%$ to $0.5\%$.

Menstrual Cycle Regulation

A negative feedback loop where FSH and LH from the pituitary stimulate the ovaries, while estrogen and progesterone from the ovaries suppress the pituitary.

Birth Control Pills

Contraceptives that provide synthetic estrogen and progesterone to suppress the LH surge that triggers ovulation.

Menopause

The cessation of estrogen production (usually between ages 45–55) that ends the menstrual cycle and accelerates bone loss, increasing osteoporosis risk.

Hormone Replacement Therapy (HRT)

A treatment currently considered safe for most women under 60 for up to 5 years, previously limited by health fears following the 2002 Women's Health Initiative study.

Women's Health Initiative (WHI) Study

A landmark HRT study whose primary limitation was only evaluating older women in their 60s–70s rather than women just entering menopause.

Intersex Conditions

Conditions in which anatomy or chromosomes do not fit typical definitions of male or female, affecting an estimated $0.018\%$ to $1.7\%$ of people worldwide.

Viagra

A drug discovered accidentally during heart trials that increases blood flow by suppressing the enzyme PDE5, which normally breaks down cyclic GMP.

Viral STIs

Sexually transmitted infections (such as HIV, herpes, HPV, and Hepatitis B/C) that have no cure and are managed only through symptom control.

Bacterial STIs

Sexually transmitted infections (such as gonorrhea, chlamydia, and syphilis) that can be cured using antibiotics.

Mitosis and Cell Differentiation

The two processes required for human development, where cell division adds more cells and cells specialize into the ~210 tissue types in the body.

Blastocyst

A structure formed 3–5 days after fertilization that contains embryonic stem cells capable of differentiating into any tissue type.

Induced Pluripotent Stem Cells (IPSCs)

Adult skin cells reprogrammed to behave like embryonic stem cells, avoiding the ethical controversy of embryo destruction.

BRCA1 and BRCA2

Tumor suppressor genes whose mutations significantly raise the risk of breast cancer (up to $55\%$–$65\%$ with BRCA1) and ovarian cancer.

Prophylactic Mastectomy

Preventive surgical removal of breast tissue for women with BRCA mutations to dramatically reduce cancer risk before it develops.

Dolly the Sheep

The first cloned mammal (1996), created after 277 attempts, which proved adult DNA can be restarted as if it were a zygote.

Therapeutic Cloning

A cloning process used specifically for stem cell production that does not produce a baby.

Nondisjunction

An error during meiosis where chromosomes fail to separate properly, causing chromosomal abnormalities such as Down Syndrome (Trisomy 21).

Carriers

Individuals with genotype $Nn$ who carry one copy of a recessive disease allele without exhibiting the disease itself.

Sex-Linked Inheritance

An inheritance pattern (such as Hemophilia on the X chromosome) where males need only one copy of a recessive allele to express the condition.

CRISPR

A revolutionary gene-editing tool that can cut and modify DNA sequences to potentially treat diseases like sickle cell.