Biology: Reproductive Strategies

A method of reproduction where offspring are genetically identical to the parent.

The cell division process in asexual reproduction.

Reproduction involving the union of two gametes (sperm and egg).

Reproductive cells (sperm and egg) produced by meiosis in gonads.

A type of reproduction where offspring arise from unfertilized eggs.

A reproductive strategy where one organism has both testes and ovaries.

A fertilized egg.

Sex organs (testes or ovaries) where gametes are produced.

Embryonic sex is determined by the sex chromosomes. XY embryos become male, XX embryos become female.

The gene on the Y chromosome that triggers male development by converting gonads into testes.

The male gamete (reproductive cell) specialized for carrying genetic information.

Male reproductive organs that produce sperm and male hormones.

A sac that holds the testes outside the body to maintain a lower temperature for sperm development.

The process of sperm formation in the seminiferous tubules of the testes.

Coiled tubes inside the testes where spermatogenesis occurs.

Categorization of a newborn based on observable physical attributes (genitalia).

Tubes that extend from the uterus, where fertilization occurs.

Another name for the oviduct, the site of fertilization.

An egg can only develop for 24 hours after ovulation.

Sperm can survive for up to 6 days in the female reproductive tract.

Outer layer of the oocyte that sperm must penetrate.

Inner layer of the oocyte, also requiring sperm penetration.

First phase of the menstrual cycle, involving egg maturation and ovulation.

Second phase of the menstrual cycle, preparing the body for pregnancy.

Sperm cells are initially produced in the testes and then mature in the epididymis.

The epididymis is a long, coiled tube where sperm cells mature and gain motility.

Mature sperm consists of a head, body, and tail, each serving a specific function.

From the epididymis, sperm travels through the vas deferens to the urethra.

The penis contains three cylinders of spongy tissue, filled with blood during an erection.

Erection occurs when nerve impulses cause blood vessels in the penis to expand, filling the spongy tissue with blood.

The forceful ejection of semen from the urethra, stimulated by nerve impulses and muscle contractions.

Semen consists of sperm and secretions from glands, like the prostate, which provide energy for the sperm.

Rapid cell division in a zygote, forming smaller cells that eventually form a hollow ball called a blastocyst.

A hollow ball of cells formed during early embryonic development, containing an inner cell mass and outer trophoblast.

A cluster of cells inside the blastocyst that will develop into the embryo.

The outer layer of cells in the blastocyst that releases hCG and helps with implantation.

The process where the blastocyst burrows into the uterine lining.

A membrane that encloses and protects the developing embryo.

A membrane that forms from the trophoblast and interacts with the uterine tissue to create the placenta.

An organ that connects the developing embryo to the mother's blood supply, providing oxygen and nutrients.

Oxytocin, a hormone, is released when a baby suckles at the breast. This triggers the release of milk from the mammary glands.

Allometric growth refers to the fact that different parts of a baby's body grow at different rates after birth.

Contraception methods are different ways to prevent pregnancy without stopping sexual intercourse.

Abstinence is a method of contraception that involves refraining from any sexual contact.

Gonorrhea is a sexually transmitted disease caused by bacteria. It can cause discharge from the penis or vagina.

Chlamydia is a sexually transmitted disease caused by the bacteria Chlamydia trachomatis. Women usually experience no symptoms until the infection is established.

Syphilis is a sexually transmitted disease caused by the bacteria Treponema pallidum. If left untreated, it can lead to serious health issues.

Genital Herpes is a common STD caused by the herpes simplex virus type 2 (HSV-2). It produces red blisters on the genitals.

A gene, like the SRY gene, that influences development of male or female characteristics.

The primary sex organs in humans: ovaries in females and testes in males.

The SRY gene on the Y chromosome controls the conversion of gonads into testes in developing males.

A pouch that holds the testes outside the body, keeping sperm at a cooler temperature for proper development.

Coiled tubes inside the testes where sperm production (spermatogenesis) occurs.

Sperm development requires a temperature cooler than the rest of the body, which is why the testes are located in the scrotum.

A child's sex is typically assigned based on the external genitals they are born with.

A person's sense of their own gender, which might or might not match their assigned sex.

The female sex cell is called an ovum, or egg. It is produced in the ovaries and is responsible for carrying half of the genetic information needed for reproduction.

At birth, a female's ovaries contain approximately 2 million oocytes. This number will decrease over her lifetime.

A primary oocyte is an immature egg cell that has begun the first meiotic division but is paused until puberty.

FSH and LH are hormones produced by the pituitary gland, which trigger the development and release of oocytes during ovulation.

Fallopian tubes, also called oviducts or uterine tubes, transport eggs from the ovaries to the uterus. They are also the sites of fertilization.

The endometrium is the inner lining of the uterus. It is shed during menstruation and is responsible for providing a suitable environment for implantation of a fertilized egg.

The cervix is the narrow, muscular opening between the uterus and the vagina. It helps to protect the uterus from infection and regulates the flow of menstrual blood.

Ovulation is the process in which a mature egg is released from the ovary and travels down the fallopian tube.

The rapid cell divisions in a zygote, creating smaller cells that will ultimately form the blastocyst.

A hollow ball of cells (500-2000) that forms during early development, containing the inner cell mass (future embryo) and the outer trophoblast.

A cluster of cells within the blastocyst that will develop into the embryo.

The outer layer of cells in the blastocyst that releases hCG and helps with implantation.

The process where the blastocyst burrows into the uterine lining.

A membrane that encloses and protects the developing embryo.

A membrane that forms from the trophoblast and interacts with the uterine tissue to create the placenta.

An organ that connects the developing embryo to the mother's blood supply, providing oxygen and nutrients.

During the first three months of pregnancy, the developing human is called an embryo. After the third month, it becomes a fetus.

Fine hair that covers the head and body of a fetus during the fifth month of pregnancy.

By the end of the sixth month, a fetus cannot survive outside the uterus without significant medical intervention.

The placenta provides oxygen and nutrients to the fetus while removing waste products.

All of the growth during the third trimester is fueled by the nutrients and oxygen passed from the mother's blood to the fetus through the placenta.

Oxytocin and prostaglandins work together to stimulate uterine contractions during labor.

Prolactin stimulates milk production in the mammary glands usually three days after birth.

The average pregnancy lasts about 40 weeks from the last menstrual cycle to the baby's birth.

Oxytocin, a hormone, is released during breastfeeding. It stimulates the release of milk from the mammary glands, triggered by the infant's suckling.

Allometric growth refers to the different rates at which various parts of a baby's body grow after birth.

Sex in mammals is determined early in development by sex chromosomes. XX embryos develop as female and XY embryos develop as male.

The SRY gene, located on the Y chromosome, controls the development of male characteristics by triggering the gonads to become testes.

The scrotum is a sac that holds the testes outside of the body, maintaining a cooler temperature ideal for sperm development.