Chapter 47: Animal Reproduction and Development

________ is the fusion of sperm and egg to form a zygote.

________ is the formation of ova (singular: ovum)

________ includes the labia minora (singular: labium minus) and the labia majora, the clitoris, the opening of the urethra, and the opening of the vagina.

The egg is "laid "from the ________- a chamber that the reproductive, digestive, and excretory systems flow into and that opens to the environment.

In ________, offspring also develop inside the mothers body but are nourished by nutrient- rich yolk stored in the egg.

________ are oviparous " (egg- bearing "）animals that lay an amniotic egg protected by a hard shell; most mammals are viviparous ("live bearing) "，and embryonic development takes place entirely within the mothers body.

________ occurs in a diversity of lineages, including certain invertebrates, fishes, lizards, snakes, and birds.

Arteries transport blood from the circulatory system of the fetus, through the ________, to an extensive capillary bed in the placenta.

________ and lactation- providing milk that nourishes offspring after birth- represent some of the most extreme forms of parental care known in animals.

________ from the mothers uterus also form part of the placenta.

A(n) ________ is also known as a mature egg.

There is a distinction between the trophoblast and the ________- the embryo develops from the ________, and the trophoblast forms part of an organ called the placenta.

A vas deferens is a tube with smooth muscle in its walls that transports sperm from the epididymis to the ________ duct within the prostate gland, where the sperm are mixed with accessory fluids.

________ in mammals results in a type of blastula called a blastocyst " (sprout- bag), "which has two populations of cells.

In the ________, diploid cells called oogonia (singular: oogonium) divide by mitosis.

Inside the ________ is a fluid filled cavity (blastocoel) and a cluster of cells called the inner cell mass (ICM)

In the ________, diploid cells called spermatogonia (singular: spermatogonium) divide by mitosis.

The cells that are created during cleavage are called ________.

The ________ holds the testes; the penis functions as the organ of copulation, or sexual intercourse, necessary for internal fertilization.

Each ________ develops into a spermatozoan (plural: spermatozoa), also commonly known as sperm- a cell that is specialized for carrying a haploid genome from the male through the female reproductive act and fertilizing an egg.

________, in contrast，typically involves the fusion of haploid gametes and results in offspring that are genetically different from each other and from their parents.

When cleavage is complete, the embryo in many animals consists of a(n) ________ called a blastula.

In ________ (literally， "virgin- origin) "， females develop eggs and produce offspring without any genetic contribution from a male.

________ are called testes; female gonads are called ovaries.

by meiosis, males produce haploid sperm and females produce haploid eggs, and these gametes fuse to create diploid offspring

ovum)

spermatogonium) divide by mitosis

spermatozoa), also commonly known as sperm-a cell that is specialized for carrying a haploid genome from the male through the female reproductive act and fertilizing an egg

oogonium) divide by mitosis

labium minus) and the labia majora, the clitoris, the opening of the urethra, and the opening of the vagina