Chapter 47: Animal Reproduction and Development

Fertilization

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

Oogenesis

________ is the formation of ova (singular: ovum)

Female genitalia

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

cloaca

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

ovoviviparous species

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

Birds

________ 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.

Parthenogenesis

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

umbilical cord

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

Pregnancy

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

Cells

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

ovum

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

ICM

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.

short ejaculatory

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.

Cleavage

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

female gonad

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

trophoblast

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

male gonad

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

blastomeres

The cells that are created during cleavage are called ________.

saclike scrotum

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

haploid spermatid

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.

Sexual reproduction

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

mass of blastomeres

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

parthenogenesis

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

Male gonads

________ are called testes; female gonads are called ovaries.

Once the males have matured, sexual reproduction ensues

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

Oogenesis is the formation of ova (singular

ovum)

In the male gonad, diploid cells called spermatogonia (singular

spermatogonium) divide by mitosis

Each haploid spermatid 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 the female gonad, diploid cells called oogonia (singular

oogonium) divide by mitosis

Female genitalia includes the labia minora (singular

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