Unit A Section 2.2

Question 1

Reproduction

Answer 1

Reproduction produces new individuals of a species. The way a species reproduces determines how much variation the new individuals will have.

Question 2

Asexual reproduction

Answer 2

Asexual reproduction involves only one parent.

Question 3

Side effects of asexual reproduction

Answer 3

All the offspring that result from asexual reproduction are identical to that parent. In other words, they all inherit identical characteristics because the adult makes an exact copy of itself.

Question 4

Different forms of asexual reproduction:

Answer 4

binary fission, budding, spore production, and

vegetative reproduction.

Question 5

Binary Fission

Answer 5

Only one-celled organisms, such as bacteria, and some protists, such as amoebas and some algae, reproduce by binary fission. During binary fission, a cell splits exactly in two, producing two identical individuals.

Ex Bacteria and amoeba and algae

Question 6

Budding

Answer 6

-Organisms such as hydra and yeast reproduce asexually by budding.
-During budding, the parent produces a small bud or a smaller version of itself
-In animals, such as hydra, the bud eventually detaches and becomes a new individual identical to its parent. –This is also true of yeast.
-In other animals, such as coral, the offspring remains
attached to the parent, forming a large structure composed of many identical individuals.

-ex. (hydra, yeast, coral)

Question 7

Spore Production

Answer 7

• Many fungi, green algae, some molds, and non-flowering plants such as ferns reproduce
• Spores are similar to seeds but are produced by the division of cells of the parent, not by the union of two
  cells.
• One individual will produce many spores, and each spore can develop into a new individual identical to the parent.
• Spores can survive unsuitable growing conditions because they remain dormant. When conditions improve, spores can produce new plants

Example -fungi, green algae, moulds, ferns

Question 8

Parthenogenesis,

Answer 8

meaning “virgin birth” in Greek, is the term used to
describe the process that transforms unfertilized
eggs into mature organisms.

(ants and bees, and snakes)

Question 9

Vegetative Reproduction

Answer 9

Vegetative reproduction is the reproduction of a plant that does not involve the formation of a seed.

• If you take a cutting from a coleus plant and place it in water, the cutting will grow roots and eventually develop into a whole new plant
• . Many plants, such as strawberries or spider plants, grow runners that produce new plants along with them.
• Tubers, such as potatoes on a potato plant, and bulbs, from which daffodils and tulips develop, are also forms of vegetative reproduction.
• The roots of aspen trees produce a form of shoot called a sucker. If the sucker becomes physically separated from the original tree, it will grow into a new aspen tree (Figure 2.6). In all these cases, the new individual plants that are produced will be genetically identical to their parent plant and to one another.

-Includes; cuttings, runners, suckers, tubers.
-Examples - coleus plant, strawberries,
aspen, potatoes

Question 10

Sexual reproduction

Answer 10

Sexual reproduction usually involves two individuals

- The offspring of sexual reproduction will have a mix of the characteristics of both individuals,

Question 11

Is sexual reproduction always between male or female:

Answer 11

However, sexual reproduction also occurs in species that we may not think of as having males and females, such as flowering plants and coral.

Question 12

gametes

Answer 12

Sexual reproduction in plants or animals relies on the union of two specialized cells are known as gametes
-A gamete has one role which is to join with another gamete

Question 13

The male gametes

Answer 13

are called sperm cells

Question 14

female gametes

Answer 14

are known as egg cells (ova)

Question 15

Sexual Reproduction in Animals Process

Answer 15

• The union of the sperm cell with the egg cell occurs during mating and is called FERTILIZATION
• The cell created by the joining of the two gametes is known as a zygote
• The zygote is the first cell of a new individual. The zygote then divides into two cells. The same divisions are repeated during a process called CLEAVAGE.
• Continued cell division results in a new multicellular life form referred to as an EMBRAYO.

Question 16

Development of the embryo;

Answer 16

-Depending on the species, the development of the embryo may occur inside the female parent, which happens in most mammals, or outside, in an egg, which happens in most other types of animals.

Question 17

What is the result of the sexual reproduction process is complete

Answer 17

The new individual will show some of the characteristics of its female parent and some of its male parent. But it will not be identical to the parent.

Question 18

Hermaphrodites

Answer 18

Hermaphrodites can produce both male and female gametes. Although most slugs and worms usually prefer to mate with other individuals of their species, in times of environmental stress, they can fertilize themselves.

Question 19

Sexual Reproduction in Plants Process

Answer 19

• Most plants produce both male and female gametes. However, some produce only female gametes and others only male.
• A gamete in the pollen grain and a gamete in an ovule join and, as in animals, a zygote is formed.
• The zygote then begins a series of divisions to produce an embryo.
• The embryo will eventually develop into a new individual. In most plants, the embryo is produced inside a seed.
• The seed protects the embryo and stores food for the embryo to use when it begins to grow into a new individual.
• Unlike animals, the new embryo may not begin to grow for some time but stays dormant within the seed until it has suitable growing conditions.

Question 20

Parts of a plant in reproduction

Answer 20

• Pollen contains the male gametes of a
  plant.
• Pollen is found on the stamen, or male part, of the plant
• Ovules contain the female gametes of a plant.
• Ovules are found in the pistil or female part of the plant.

Question 21

Pollination

Answer 21

Pollination occurs when pollen is transferred from the anther of the stamen to the stigma of the pistil

Question 22

Fertilization

Answer 22

Fertilization occurs when the male and female gametes unite.

Question 23

Cross-pollination

Answer 23

Cross-pollination occurs when the pollen of one plant is carried to the stigma of another by wind, water, or animals

Question 24

Cross-fertilization

Answer 24

Cross-fertilization occurs when a grain of this pollen

produces a long tube that eventually grows down the style into the ovary that contains the ovules.

Question 25

Which part of the plant contains sex cells

Answer 25

Pollen grains and ovules are sacs that contain sex cells

Question 26

What is the outcome of the offspring in cross-fertilization:

Answer 26

• Plants that are produced from cross-fertilization will show some of the characteristics from the parent that donated female gametes and some from the parent that donated male gametes.
• It will not be identical to either parent.

Question 27

Advantages of Asexual Reproduction

Answer 27

• Asexual reproduction does not require any specialized cells or a way of bringing gametes together
• asexual reproduction can produce lots of individuals very quickly.
• This is a great advantage in environments that do not change very much
• It takes less time and less energy

Question 28

Disadvantages of Asexual Reproduction

Answer 28

-There is no variation among the population
- if conditions become unfavorable, the entire population may be wiped out.
-

Question 29

Advantages of Sexual Reproduction

Answer 29

• advantage of providing lots of variation, which helps species survive environmental change.

Question 30

Disadvantages of Sexual Reproduction

Answer 30

• it takes a lot of energy
• More time to produce the offspring
• can only produce a limited number of offspring.

Question 31

How do plants produce sexually and asexually:

Answer 31

• Most plants that produce seeds by sexual reproduction can also reproduce asexually, either from cuttings or by producing structures such as bulbs or runners.
• Some plants can use their seeds to reproduce both asexually and sexually. In the asexual method, embryos develop in the seeds without the contribution of sperm cells. These seeds will grow into plants that are genetically identical to the parent plant.

Question 32

How some animals produce sexually and asexually:

Answer 32

• Throughout the growing season, females (aphids: insects) produce live female young without fertilization, or asexually
• Over the summer, several generations are produced. In the fall, when the days are short and cold, females produce a generation that includes both males and females.
• These males and females reproduce sexually and lay eggs that will hatch in the spring to produce new colonies.
• To reproduce sexually, sponges release sperm cells into the water, which are captured by special cells and carried to egg cells

Question 33

male reproductive part

PLANT

Answer 33

Stamen

Question 34

female reproductive part

Answer 34

Carpel: Pistil

Question 35

Plant female gamete

Answer 35

egg cell/ ova

Question 36

Plant male gamete

Answer 36

pollen

Question 37

Internal fertilization

Answer 37

fusion of gametes happen inside the
females body

Ex. Mammal

Question 38

External fertilization

Answer 38

The fusion of gametes happens outside the body.

Ex. frogs and fish