Reproduction In Flowering Plants

Question 1

Define reproduction:

Answer 1

• Reproduction is the biological process by which a new individual is produced from an already existing individual.

Question 2

What is essential for the survival and evolution of a species?

Answer 2

• Genes being transferred to next generation is essential for the survival and evolution of a species.

Question 3

Characteristics of Asexual Reproduction:

Answer 3

• one parent
• all offspring has same genetic info as parent.
• no gametes
• mitosis
• produces clones.

Question 4

Characteristics of Sexual Reproduction:

Answer 4

• two parents
• mixture of genetic info
• gametes (sperm and ova)
• Meiosis
• Fertilisation -> gametes

Question 5

List the types of Asexual Reproduction:

Answer 5

• binary fission
• Fragmentation
• budding
• spore formation
• Regeneration
• Vegetative reproduction
• grafting

Question 6

What is binary fission as asexual reproduction?

Answer 6

A single parent cell divides into two daughter cells.

e.g: amoeba, bacteria

Question 7

What is grafting as asexual reproduction?

Answer 7

• Tissue from one plant is inserted into those of another.

Question 8

Pros of Asexual Reproduction:

Answer 8

• lots of offspring in favourable conditions.
• No energy -> no gametes
• offspring same as parent which is suited to environment
• no need to find mate or pollinator

Question 9

Cons of asexual reproduction:

Answer 9

• could cause over Population
• no genetic variation -> adaptation is hard
• shared weak characteristics -> decreased survival.

Question 10

Pros of sexual reproduction:

Answer 10

• gene variation-> more adaptable -> higher survival rate
• basis of evolution
• “Reshuffling of genes” -> lower chance of inheriting harmful genes

Question 11

Cons of Sexual reproduction:

Answer 11

• fewer offspring
• high Energy cost -> flowers
• process is slower
• negative mutations can appear
• need agents (wind/insects)

Question 12

What is a flower?
-what do they contain?

Answer 12

• A flower is an organ of sexual reproduction.
• contain both male and female gametes.

Question 13

Flower likely evolved from…

Answer 13

Flowers likely evolved from specialised leaves.

Question 14

What is the difference between pollination and fertilisation?

Answer 14

• pollination -> transfer of pollen from one flower to another
• fertilisation -> occurs after pollination and is the joining of male and female gametes in the ovule to form a zygote

Question 15

What are the two different types of pollen transfer?

Answer 15

• self pollination
• cross pollination

Question 16

What are the two different types of self pollination?

Answer 16

Type 1 -> within the same flower

Type 2 -> within different flower of same plant.

Question 17

Is self-pollination considered Asexual reproduction?

Answer 17

No, the gametes are different to parent cell therefore it is sexual reproduction.

Question 18

Why do plants avoid self-pollination?

Answer 18

• it is avoided as it doesn’t create much genetic variation in offspring.

Question 19

What happens during pollination?

Answer 19

1. when an anther is mature, it splits open and discharges pollen.
2. the pollination is carried to the sigma by various agents.

Question 20

What strategies do plants have to avoid self-pollination?

Answer 20

• timing -> male and female structures mature at different times.
• Morphological -> structure of organs prevent it
• Biochemical-> chemical on surface of pollen and stigma that prevents pollen tube germination on the same flower.

Question 21

What is cross pollination?

Answer 21

• pollen is transferred from anther of a flower on one plant -> to stigma of a flower on another plant.

Question 22

Fertilised ovules __ __ __ and the ovary __ __

Answer 22

Fertilised ovules develop into seeds and the ovary into fruit.

Question 23

Describe what a fertilised ovule is:

Answer 23

Fertilised ovule -> seed which encloses and protects the embryo and endosperm.

Question 24

What is the hardened tissue around the seed called?

Answer 24

-Testa (seed coat)

Question 25

What does a fruit do?

Answer 25

A fruit protects the seed and helps with dispersal.

Question 26

Embryo becomes what?

Answer 26

Embryo becomes a cotyledon which stores food and absorbs nutrients.

Question 27

What is germination?

Answer 27

Germination -> when seeds absorb water.

Question 28

Why are seed producing plants so successful?

Answer 28

- adapted for dispersal - seeds store reserves (survive harsh conditions) - hard testa (protects embryo) - cotyledons -> food for developing plants

Question 29

What seeds are used as food?

Answer 29

- grains -> starch and fibre -legumes -> protein, low fat, fibre -Nuts -> protein, fibre, unsaturated fats

Question 30

What is a seed bank?

Answer 30

- A seed bank is a place where seeds are stored to preserve genetic diversity for the future.

Question 31

Humans have _\_\_ _\_\_ _\_ for their use, which involved…

Answer 31

Humans have domesticated wild plants for their use, which involved skilful breeding to get desired traits.

Question 32

How _does_ asexual reproduction improve crops?

Answer 32

- asexual reproduction produces clones of parent plant - if a mutation occurs it could produce a plant with a new superior trait -> if that plant is reproduced by asexual means -> the offspring will get that superior trait.

Question 33

How _does_ sexual reproduction improve crops?

Answer 33

- sexual reproduction creates genetic Variation -> offspring would be different from parent -> Some of the differences were beneficial -> breeders would plant seeds from superior plants while eliminating bad seeds -they often cross pollinate to produce new crop varieties with superior traits

Question 34

Asexual reproduction and genetic engineering could be the solution to…

Answer 34

Asexual reproduction and genetic engineering could be the solution to the imminent food crisis.

Question 35

How could asexual reproduction benefit _future_ crop production?

Answer 35

- propagation is faster than from seed (due to no gametes) - all propagated plants are considered superior quality - large quantities of plants can be produced cheaply, easily and quickly - using grafting, fruit trees will grow more quickly to fruit production - Micro-propagation can produce numerous new identical clones

Question 36

How does genetic engineering benefit crop production?

Answer 36

- Production of new variety with desired trait is achieved more quickly than conventional breeding methods - No interspecies barriers since all organisms use the same genetic code.

Question 37

What traits are biotechnologists trying to incorporate into food crops?

Answer 37

- flood tolerance - resistant to diseases and herbicides - increased tolerance to insect pests - nutrient-content enrichment - increased tolerance to environmental pressures - longer shelf storage life.

Question 38

How do breeders use Sexual Reproduction to improve food crops?

Answer 38

- crop breeders hybridise plants - Hybrid crops are produced by cross-pollinating two inbred plants of dissimilar genotype -> resulting in genetic variation

Question 39

What improvements have been made through sexual reproduction of food crops?

Answer 39

- more vigorous - improved disease resistance - earlier maturity and extended growing season - increased yield - quality improvements