Sexual Reproduction in Humans

To produce fluid called semen that provides nutrients for sperm cells.

The sperm duct carries sperm and mixes it with fluids produced by glands before ejaculation.

The urethra carries urine from the bladder and semen during ejaculation.

<p>To produce sperm and testosterone.</p> Signup and view all the answers

<p>The scrotum keeps the testes at a temperature slightly lower than body temperature.</p> Signup and view all the answers

<p>To pass urine out of the body and allow semen to enter the vagina during intercourse.</p> Signup and view all the answers

<p>It mixes sperm with fluids produced by glands.</p> Signup and view all the answers

<p>Testosterone regulates the development of male reproductive tissues and secondary sexual characteristics.</p> Signup and view all the answers

<p>The placenta facilitates the exchange of nutrients like glucose and oxygen to the fetus, while also removing waste products such as carbon dioxide and urea.</p> Signup and view all the answers

<p>The placenta has a large surface area and a thin wall, which optimize it for efficient diffusion of molecules between the mother and fetus.</p> Signup and view all the answers

<p>The ability of toxins and viruses to cross the placenta primarily depends on the size of the molecules; smaller molecules can pass through more easily.</p> Signup and view all the answers

<p>Rubella can cause serious health issues such as deafness, heart disease, and eye problems in the fetus.</p> Signup and view all the answers

<p>Smoking can introduce harmful substances like nicotine that may cross the placenta, potentially harming the developing fetus.</p> Signup and view all the answers

<p>Growth of penis and testes, facial and body hair, muscle development, and voice breaking.</p> Signup and view all the answers

<p>Around age 12.</p> Signup and view all the answers

<p>The peak in oestrogen levels that occurs just before day 14.</p> Signup and view all the answers

<p>The uterine lining breaks down, leading to menstruation.</p> Signup and view all the answers

<p>About 28 days.</p> Signup and view all the answers

<p>They control the menstrual cycle by regulating oestrogen and progesterone levels.</p> Signup and view all the answers

<p>Increased interest in sex and mood swings.</p> Signup and view all the answers

<p>Around 5 to 7 days.</p> Signup and view all the answers

<p>The sperm has a flagellum (tail) that enables it to swim to the egg.</p> Signup and view all the answers

<p>The enzymes help digest through the jelly coat and cell membrane of the egg when the sperm meets the egg.</p> Signup and view all the answers

<p>Mitochondria provide energy from respiration for the flagellum to move back and forth for locomotion.</p> Signup and view all the answers

<p>The cytoplasm contains a store of energy that provides resources for the dividing zygote after fertilization.</p> Signup and view all the answers

<p>The coating changes to form an impenetrable barrier that prevents other sperm nuclei from entering the egg cell.</p> Signup and view all the answers

<p>Sperm are very small (45µm), while eggs are larger (0.2mm).</p> Signup and view all the answers

<p>Sperm have a head region and flagellum with many structural adaptations, while eggs have a round cell covered in a jelly coating.</p> Signup and view all the answers

<p>Sperm are produced every day in huge numbers (around 100 million), while females have thousands of immature eggs but only release one each month.</p> Signup and view all the answers

<p>Follicle-stimulating hormone (FSH)</p> Signup and view all the answers

<p>LH is released, causing ovulation.</p> Signup and view all the answers

<p>Progesterone maintains the thickness of the uterine lining.</p> Signup and view all the answers

<p>The uterine lining breaks down, leading to menstruation.</p> Signup and view all the answers

<p>FSH stimulates the ovaries to produce oestrogen.</p> Signup and view all the answers

<p>LH causes ovulation and stimulates the production of progesterone.</p> Signup and view all the answers

<p>Oestrogen peaks just before day 14.</p> Signup and view all the answers

<p>They lead to egg maturation and increased oestrogen release.</p> Signup and view all the answers

<p>FSH stimulates the development of a follicle in the ovary, leading to egg development.</p> Signup and view all the answers

<p>Oestrogen promotes the growth and repair of the uterus lining.</p> Signup and view all the answers

<p>Progesterone levels drop, leading to the breakdown of the uterine lining and menstruation.</p> Signup and view all the answers

<p>A high enough level of oestrogen stimulates the release of LH from the pituitary gland.</p> Signup and view all the answers

<p>The corpus luteum produces progesterone.</p> Signup and view all the answers

<p>The uterine lining breaks down, resulting in menstruation.</p> Signup and view all the answers

<p>Progesterone maintains the uterine lining and prevents its breakdown until the placenta develops.</p> Signup and view all the answers

<p>The interactions between FSH, oestrogen, LH, and progesterone control follicle development, ovulation, and the maintenance of uterine lining.</p> Signup and view all the answers