BIO 1002 final
most fetuses can survive outside the womb after a minimum of _________ weeks
20
a human embryo is known as a fetus after
8 weeks
what is special about indirect development?
because they change form, they serve different roles in environment. many offspring produced
during the embryonic stage, a hollow ball of cells is known as
blastula
the metamorphosis of a caterpillar into a butterfly is an example of
indirect development
endoderm
inner layer. formation of lining of organs and systems
an incomplete flower
lacks one or more of the four basic floral parts
an onion bulb is made up of ________ that are specially adapted for food and water storage
leaves
a pollen grain is actually the
male gametophyte
Blastocyst
mammalian blastula in which some differentiation of cells has occurred.
organogenesis
master-switch genes. genetically directing how genes play a role in development
development
mechanism how an organism grows in complexity and organization
meiosis produces a ________, which eventually gives rise to an egg in an unfertilized seed
megaspore
__________ results in the production of spores in flowering plants
meiosis
plant cells that are actively dividing are _____ cells
meristem
what cell type permits the continued growth of a plant throughout its life?
meristem cells
your biceps muscle is derived from the
mesoderm
mesoderm
middle layer. contributes to digestive tract, skeleton and muscles, hair
colostrum
milk that is not mature yet, high in proteins, yellow in color
what type of cell activity occurs in the meristem regions of plants?
mitosis
which flower structure is not a modified leaf?
pollen
which of these hormones stimulates the production of milk?
prolactin
mycorrhizae are symbiotic associations between fungi and plant
roots
which would you be unable to locate in xylem tissue?
sieve tube elements
blastopore
signifies beginning of gastrulation
the sporophyte produces
spores by meiosis
spores and gametes are both haploid reproductive cells. what is the difference between the two?
spores germinate and grow into a multicellular haploid gametophyte, and gametes fuse to form a diploid zygote
an oak tree is a
sporophyte
the sexual life cycle of plants is described as alternation of generations because it alternates between
sporophytes and gametophytes
what is not a major function of roots?
carrying out photosynthesis
apoptosis
cell death
the dermal tissue system consists of
epidermis
which of the following occurs in the placenta?
eroding blood vessels in the endometrium bathe chorionic villi in pools of maternal blood
T/F: the concentration of nutrients in plants is approximately the same as the concentration of nutrients in the surrounding soil
false
water flows upward in some xylem tubes and downward in others
false
the umbilical cord of a mammal connects the
fetus and the placenta
parenchyma tissue is a component of the _______ tissue system
ground
in the alternation of generations, what is formed when a spore germinates?
haploid stage called the gametophyte
a plant, such as an iris, that reproduces asexually most of the time, probably
has offspring that live in the same environment as the parents
where are apical meristems located?
at the tips of roots, shoots, and branches
as a morula, the embryo consists of
a cluster of cells that are much larger than normal cells
cleavage
a lot of cell division. CELL MASS DOES NOT CHANGE
in flowering plants, the sperm does not have to swim to the egg. the sperm reaches the eggs by
a pollen tube
which of the following is a result of gastrulation?
a three layer embryo
a flowering plant produces pollen in the
anther
flowers that make pollen, but not ovules, lack
carpels
cells that are alive, have thickened cell walls, and support the plant body are
collenchyma cells
which is incorrect of xylem tissues?
companion cells provide nutrition for tracheids
the first leaves produced by an embyro while still inside the seed are
cotyledons
parenchyma cells are located in all of the following structures except the
cuticle
the cells of an aging animal function less efficiently because
damaged DNA cannot be repaired
of the major tissue systems associated with land plants, the __________ tissue system covers the outer surface of the primary plant
dermal
the cells that line the inside of the blastopore become the
digestive tract
birds hatch out of their eggs looking like small versions of the adult. this is an example of
direct development
at which stage s the human embryo most susceptible to toxic substances?
during organogenesis
the nervous system forms from the
ectoderm
gastrulation
embryo develops into gastrula
why does direct development produce fewer offspring?
newborns tend to be larger, and they require a lot of energy and nourishment before and after birth
ectoderm
outer layer. responsible for nervous system, skin, hair
all of the following are included in the male parts of a flowers except
ovules (stamen, pollen, and anthers are)
most of the interior of a leaf consists of soft, living ________ cells
parenchyma
in the stems of plants, where is sugar converted to starch and stored as a food reserve?
parenchyma cells in both the cortex and pith
________ cells that convert sugar to starch in mature roots are part of the ________ tissue system
parenchyma, ground
________ are modified leaes that are often brightly colored and scented to attract pollinators
petals
what is the correct order of the tissues in a young dicot stem, from the center of the stem outward?
pith->xylem->vascular cambium->phloem->cortex->epidermis
why can't plants use N2 directly as a nutrient?
plants lack the enzymes necessary to convert N2 into NO3- or NH4+
sclerenchyma tissue does not store what?
sugars or starches
which of the following is a common function of stems, but not of roots?
support
Blastopore
the opening of the central cavity of an embryo in the early stage of development.
if a beaver eats the bark all the way around a tree trunk, why does the tree die?
the phloem is damaged, and the transport of sugars ceases
what is differentiation?
the process in which different cells develop into different cell types
grass flowers lack petals and sepals. which of the following statement is true?
they are incomplete flowers lacking one or more floral parts
as early as the _____ month, as the brain and spinal cord grow, the fetus can demonstrate movement and respond to stimuli
third
what are the results of double fertilization
triploid endosperm and diploid zygote
in humans fertilization occurs in the
uterine tube
conifers do not have flowers to attract pollinators. instead, fertilization occurs
via wind pollination
what diffuses from fetal blood to maternal blood in the placenta?
wastes
what type of environment is with direct development?
watery. helps with secreting wastes and gas exchange
which of the following statements is true?
when mature, the ovules will become seeds and the ovary will develop into a fruit
in humans, implantation occurs
when the zygote is a blastocyst