Overview of Animal Reproduction and Development
Which of the following describes a zygote? A fertilized ovum. A multicellular embryo. An embryo that has the three primary germ layers. An embryo that is in the process of organogenesis.
A fertilized ovum.
zygote
a fertilized ovum
asexual reproduction
a form of reproduction from a single parent that makes a clone of itself through mitosis
how does can early development of the offspring occur?
either internally or externally
hermaphrodites
organisms that have both male and female sexual organs
Which axis organizes the body from head to tail? The cerebrospinal axis The dorsoventral axis The left-right axis The anteroposterior axis
The anteroposterior axis
how does fertilization occur in many fishes?
externally outside the bodies of both parents, while in others, like mammals, fertilization occurs internally inside the female
dorsoventral axis
organizes the body from back to belly
how are some multicellular animals?
some use both asexual and sexual reproduction, while some only reproduce sexually.
endoderm
the innermost layer of cells in the early embryo
gametogenesis
which is the formation of gametes
Select the set of events, in chronological order, as they occur during sexual reproduction in multicellular animals. Gametogenesis, fertilization, cleavage, formation of the three primary germ layers, organogenesis Gametogenesis, cleavage, fertilization, formation of the three primary germ layers, organogenesis Fertilization, cleavage, gametogenesis, formation of the three primary germ layers, organogenesis Gametogenesis, fertilization, cleavage, organogenesis, formation of the three primary germ layers
Gametogenesis, fertilization, cleavage, formation of the three primary germ layers, organogenesis
Select the statement that is TRUE about animal reproduction and development. Some multicellular organisms can reproduce by both sexual and asexual reproduction. Developmental biologists mainly study human development. Organogenesis begins immediately after fertilization. Animals that reproduce asexually are called hermaphrodites.
Some multicellular organisms can reproduce by both sexual and asexual reproduction.
In the early embryo, how are the positions of the mesoderm and endoderm different? The mesoderm is the innermost layer of the cells, while the endoderm is the outermost layer. The mesoderm is the middle layer of the cells, while the endoderm is the innermost layer. The mesoderm is the outermost layer of the cells, while the endoderm is the innermost layer. The mesoderm is the innermost layer of the cells, while the endoderm is the middle layer.
The mesoderm is the middle layer of the cells, while the endoderm is the innermost layer.
why is it important that cleavage occurs early in development?
a single cell is very limited in the shapes it can form, and a single-celled zygote also cannot begin the process of differentiating into different tissue types
what are the three major body axes?
anteroposterior axis, dorsoventral axis, left-right axis
anteroposterior axis
organizes the body from head to tail
left-right axis
organizes the body from left to right
gametes
specialized sex cells produced by each parent for sexual reproduction
what are the two types of gametes?
sperm and ova
what are the three primary germ layers called?
the ectoderm, the mesoderm and the endoderm
Ova
the female gametes and are created during the process of oogenesis.
organogenesis
the formation of organs, can begin in the embryo and the different body structures can begin to take shape
Sperm
the male gametes, are created during the process of spermatogenesis
mesoderm
the middle layer of cells in the early embryo
ectoderm
the outermost layer of cells in the early embryo
cleavage
the process by which the zygote rapidly divides without growing to become multicellular
what happens after fertilization?
the zygote must establish the three major body axes.
sexual reproduction
when two parents produce offspring with unique combinations of genes from both parents
