Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BIOS TEST 2 > Plant Reproduction > Flashcards

Plant Reproduction Flashcards

1
Q

Alternation of Generations

A

two distinct multicellular stages in their life cycles, a multicellular haploid GAMETOPHYTE and multicellular diploid SPOROPHYTE
- the gametophyte produces gametes via mitosis and fuse to form a diploid zygote
- the SPOROPHYTE is created when the zygote develops into a mature multicellular diploid individual, which then produces haploid spores via meiosis
- the spores develop into a mature multicellular haploid individuals
- STAGES ARE NAMED FOR WHAT THEY PRODUCE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Gamete

A

mature haploid male/female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Spore

A

typically unicellular; reproductive unit capable of giving rise to a new individual without sexual fusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

AOG Variations in Plant Lineages

A
  • Seedless Nonvascular (bryophytes) plants have a gametophyte-dominated life cycle
  • Seedless Vascular plants are sporophyte-dominated life cycle
  • Gymnosperms are sporophyte-dominated and have no flowers, no double fertilization, and have “naked seeds”
  • Angiosperms are sporophyte-dominated and have flowers, double fertilization, and fruit-covered seeds

Gymnosperms and angiosperms both produce pollen which delivers sperm to eggs without water, and seeds protect the embryo for dispersal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Reproduction in Angiosperms

A

angiosperms have 3 defining features: flowers, double fertilization, and fruit-covered seeds
- FLOWERS: attract animal pollinators
- DOUBLE FERTILIZATION: invest resources for nourishment of the developing embryo
- FRUITS: facilitate seed dispersal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Flower Structure

A

has four layers (listed from external to internal)
1. Sepal
2. Petals
3. Male reproductive structures
4. Female reproductive structures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Flower Structure: Sepal

A

outermost layer of a flower; green leafy structures which protect the developing flower bud before it opens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Flower Structure: Petals

A

layers inside the sepals; modified leaves which are colored to attract pollinators

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Flower Structure: Male reproductive structures

A

third layer of a flower; consists of the stamen, anthers, and filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Stamen

A

composed of anthers and filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Anthers

A

contain microsporangia, the structures that produce microspores which develop into male gametophytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Filaments

A

structures that support the anthers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Flower Structure: Female reproductive structures

A

innermost layer of a flower; consists of the carpel (which contains a stigma, style and ovary)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Stigma

A

location where pollen - male gametophytes - are deposited by wind and pollinators

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Style

A

structure that connects the stigma to the ovary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Ovary

A

contain megasporangia, structures that produce megaspores, which develop into female gametophytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Pollen

A

male gametophyte in angiosperms and gymnosperms; a multicellular, haploid organism that produces the sperm
- IMPORTANT ADAPTATION IN FACILITATING COLONIZATION OF LAND BY PLANTS DURING EARLY PLANT EVOLUTION
- its protective covering prevents desiccation of the sperm
- allows angio and gymnosperms to reproduce away from water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Microspoangium

A

structure in angiosperms where pollen is developed, located within the anthers
- pollen sacs in which the microspores develop into pollen grains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Microspore

A

haploid spore that is derived from a diploid cell
- within the microsporangium, the diploid microspore mother divides via meiosis to give rise to 4 microspores, each of which form a pollen grain
- upon maturity, the microsporangia bursts, releasing pollen grains from the anther to be transported by wind, water, or by a pollinator

20
Q

Mature Pollen Structure

A

contains TWO cells: a generative and tube cell
- the small generative cell is contained within the larger tube cell
- when the pollen grain reacts with the flower’s stigma, it undergoes pollen germination

21
Q

Pollen Germination

A
  1. the tube cell begins growing into the stigma, through the style, and down the bottom of the ovary. as it grows, it forms a POLLEN TUBE, a conduit to deliver sperm to egg
  2. the generative cell migrates through the pollen tube to the ovary for fertilization. when traveling inside the tube, the cell divides to form 2 sperm cells. BOTH are required for double fertilization
22
Q

Embryo Sac

A

female gametophyte with 2 distinct phases:
1. a single cell in the diploid megasporangium, located within the ovules, undergoes meiosis to produce 4 megaspores - only 1 survives
2. the surviving haploid megaspore undergoes mitosis WITHOUT COMPLETE CELL DIVISION, to produce an 8-nucleate, 7-cell female gametophyte: the embryo sac

23
Q

Embryo Sac Structure

A
  • 2 nuclei (polar nuclei) move to the center of the sac and fuse to form a single, diploid central cell that later fuses with the sperm cell to form the TIPLOID ENDOSPERM, which will provide nourishment for the developing embryo
  • 3 nuclei position themselves on one side of the sac and develop into the ANTIPODAL CELLS, which later degenerate into providing nourishment
  • the nucleus closest to the microphyte becomes the female gamete (egg cell)
  • 2 other nuclei develop into SYNERGID CELLS
24
Q

Microphyte

A

the site where sperm enters the embryo sac

25
Synergid Cells
use chemical signaling to help guide the pollen tube for successful fertilization
26
Embryo Development
once fertilization is complete, the resulting diploid zygote develops into the embryo, and the fertilized ovule forms other tissues of the cell - the ovule wall becomes part of the fruit - the ovule is part of the sporophyte; the structures within the embryo sac are produced by the gametophyte
27
Pollination Syndromes
the way a particular plant species is pollinated - plants pollinated by animals must attract and feed them - plants pollinated by wind and water must produce massive quantities of pollen to increase fertilization chances
28
Pollination Syndromes: Colored, highly scented flowers
pollinated by bees, butterflies, wasps, or flies - these insects are active during the day and can detect bright colors and strong smells - sweet smells attract bees and butterflies and rotting smells attract flies - many insect pollinated flowers have UV range colors that are visible to insects
29
Pollination Syndromes: White/pale colored, highly scented flowers
pollinated by moths and bats - active at night - light coloring makes them easier to see at night - tend to smell musky/fruity - flowers pollinated by bats tend to be larger than those pollinated by moths
30
Pollination Syndromes: brightly colored, odorless flowers
pollinated by birds - do not have a strong sense of smell - these flowers tend to have a curved, tubular shape to accommodate beaks
31
Pollination Syndromes: small green, petal-less flowers
pollinated by wind - these flowers do not produce nectar - must produce excessive amounts of pollen - gymnosperms are pollinated by wind
32
Pollination Syndromes: aquatic plants
pollinated by water - pollen floats and water carries it to another flower
33
Double Fertilization
two fertilization events; is unique to angiosperms - after fertilization is complete, no other sperm can enter - the fertilized ovule forms the seed - the ovary becomes the fruit, which usually surrounds the seed
34
Double Fertilization: Step 1
1. after pollen is deposited on the stigma, it germinates and grows through the style to reach the ovule 2. the pollen tube cells grow to form the tube, guided to the microphyte by synergic cell chemical signals 3. the generative cell travels through the tube to the egg and divides via mitosis to form 2 sperm cells
35
Double Fertilization: Step 2
1. one sperm fertilizes the egg cell, forming a diploid zygote 2. the other sperm fuses with the 2 polar nuclei, forming a TRIPLOID cell that develops into the endosperm
36
Endosperm
serves as a source of nutrition for the developing embryo and also after germination
37
Seed Maturation
the evolution of the seed in gymnosperms and angiosperms was an important adaptation allowing plants to colonize land away from water due to the protection of the embryo within the plant - the seed is analogous to the amniotic egg in animal reproduction - after fertilization, the seed can go through three phases: DEVELOPMENT, DESICCATION, or DORMANCY
38
Seed Maturation: Development
the zygote enters a temporary period of development where it first divides to form 2 cells: the upper (APICAL) cell andthe lower (BASAL) cell - at the same time, the endosperm accumulates starches, lipids, and proteins and nourishes the developing cotyledons (embryonic leaves) that serve a nutrient and energy storage for embryo development after germination (before the plant can photosynthesize to produce its own carbon supply)
39
Apical Cell
gives rise to the embryo - the actual embryo that will develop into a plant
40
Basal Cell
gives rise to the suspensor, which eventually makes connection with the maternal tissue - the suspensor does not becomes part of the future plant, but provides a route for nutrition to be transported from the mother plant to the growing embryo - "extra-embryonic" tissue - is analogous to the umbilical cord in placental mammals)
41
Seed Maturation: Desiccation
the seed loses up to 95% of its water; this water loss dehydrates the seed and causes extremely low metabolic activity and concentrates the seed's sugars to protect the cell from freezing - causes embryonic development to be paused
42
Seed Maturation: Dormancy
a time of no growth + minimal metabolic activity that allows time for dispersal; growth is resumed only when the seed detects growth appropriate conditions - in these conditions, the seed will then GERMINATE/RE-INITIATE DEVELOPMENT - once development is reactivated, the seedling relies on cotyledon food - some signals include: water, specific light wavelengths, cold periods, fire, and scarification
43
Fruit + Seed Dispersal
after fertilization, the ovary of the flower develops into the fruit, which allows for seed dispersal far from the mother plant in more favorable and less competitive conditions - propulsion-dispersed - wind-dispersed - water-dispersed - animal-dispersed
44
Fruit + Seed Dispersal: Propulsion
fruits "explode" out of the plant
45
Fruit + Seed Dispersal: Wind
fruits are lightweight and may have wing/parachute-like appendages that allow them to be carried by the wind
46
Fruit + Seed Dispersal: Water
fruits are light and buoyant, giving them the ability to float
47
Fruit + Seed Dispersal: Animal
fruits either have "hooks" to attach and fall off animals or are very sweet/fatty to be eaten and deposited in a new location in feces - BIRDS: fruits tend to be brightly colored - MAMMALS: fruits tend to be highly scented

BIOS TEST 2 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions