lesson 15 - animals Flashcards
what is metazoa another term for?
animals
are animals heterotrophic or heterotrophic or autotrophic?
heterotrophic eukaryotes
what is heterotrophic?
organisms eat other organisms for energy
do animals have cell walls?
no
if animals do not have cells walls, what do they rely on for support?
protein like collagen to support their cells and help them stick together
what are collagen found in?
animals and choanoflagellates
in what ways can animals reproduce asexually?
budding and parthenogenesis
what is parthenogenesis?
a female produces offspring without needing a mate
what type of life cycle do animals typically follow?
a diplontic life cycle, meaning they spend most of their lives as a diploid (2n) organism
what is oogamy?
a form of sexual reproduction where a large, non-motile egg is fertilized by a smaller motile sperm.
where do tissues in developing animals come from?
they arise from embryonic germ layers, which later form body structures
what are embryonic germ layers?
the first building blocks of an animal’s body that decide what parts of the body will form
how do porifera (sponges) eat?
water goes in through tines holes on its body
special cells called choanocytes catch the food floating in the water
amoebocytes move the food around to feed the whole sponge
where does the clean water exist through?
osculum
which part of a sponge moves food around?
amoebocytes
what do epidermal cells do?
they form the sponge’s outer layer, like skin
what catches the food?
choanocytes (collar cells)
what is the first step after fertilization?
cleavage
what is cleavage?
the zygote divides into many smaller cells without growing in size
what is it called when the dividing cells form a hollow ball?
blastula
does the overall size of the embryo increase during cleavage?
no, the cells get smaller, but the total size stays the same
what happens during gastrulation?
the cells move and organize into embryonic germ layers, which later form organs and tissues
what are the 2 germ layers?
ectoderm and endoderm
is ectoderm the outer or inner layer?
outer layer
what does the ectoderm become?
skin and nervous system
what does the endoderm become?
the lining of the digestive system and organs (liver and lungs)
do diploblasts have mesoderm?
no, they only have two layers
what is radial symmetry?
a body plan where the animals has a top and bottom, but no front, back, left or right
which animals have radial symmetry?
jellyfish, corals, and sea anemones
what is the difference between radial symmetry and bilateral symmetry?
animals can be divided into many equal parts like a pizza, while bilateral symmetry means it has a left and right side (humans)
what are two body forms?
polyp and medusa
does a polyp move?
no
does medusa move through water to catch prey?
yes
what are the major types of early animal development?
protostomes (mouth forms first) and deuterstomes (anus forms first)
which group do humans belong to?
deuterstomes
